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J Thiele

Publications and source records attributed to J Thiele.

At least 73 records · Page 4Linked to original sources
PubMed2001

p21/waf1/cip1 in gastric cancer: associations with histopathological subtypes, lymphonodal metastasis, prognosis and p53 status.

BACKGROUND: Cyclins and cyclin-dependent kinases are determining factors of the cell cycle. In the present study, we investigated the role of p21 and p53 in the biology of gastric cancer, focusing on its influence on progression and prognosis (n = 195). METHODS: P21 and p53 immunoreactivity was analysed immunohistochemically, applying monoclonal antibodies. The p53 status was comparatively evaluated by PCR-SSCP analysis of p53 mutations in selected tumours. RESULTS: Fifty-eight percent of the carcinomas were p21+ in more than 5% of the cancer cell nuclei, whereas 19% exhibited a p21 immunoreactivity in more than 20% of the nuclei. On the other hand, p53 was over-expressed (in more than 50% of the nuclei) in about 45% of the specimens. P21 immunoreactivity in more than 5% of the nuclei was inversely related to the pN as well as pTNM cancer stage, whereas only a strong p21 expression (in >20% of the nuclei) was correlated with a better survival probability in a univariate analysis. The p53 status was associated with lymphonodal metastasis, but not with prognostic data. In multivariate survival analyses, neither p21 nor p53 emerged as independent prognostic factors. Compared with the results of p53 mutation analysis by PCR-SSCP. p21 immunoreactivity was reduced in p53-mutated cases. CONCLUSIONS: These features show an association of p21 over-expression with certain clinico-pathological parameters of gastric cancer. In this context, our data suggest that p21 immunoreactivity in more than 5% of the tumour cells has a predictive value for the course of adenocarcinoma of the stomach.

Adenocarcinoma↗
PubMed2001

Therapy-related changes of CD34+ progenitor cells in chronic myeloid leukemia: a morphometric study on sequential trephine biopsies.

In chronic myeloid leukemia (CML), it has been assumed that the number of CD34(+) progenitor cells (PGCs) provides useful diagnostic and prognostic information regarding the evolution of accelerated phase and blastic crisis. However, until now no information is available about changes of this peculiar precursor cell population during therapy or possible associations with the other bone marrow constituents. For this reason, a retrospective clinicopathological study was performed on 83 patients with CML including 209 sequential bone marrow biopsies (intervals ranging between 6 and 143 months) and immunohistological staining of CD34(+) cells (QBEND10), megakaryocyte precursors (CD61), and erythropoiesis (Ret 40f). According to treatment modalities, three different groups of patients could be distinguished that received either monotherapy by interferon-alpha2b (IFN-alpha2b) or hydroxyurea (HU) and a combination of both. In comparison with a control group, morphometry revealed a significant increase in the quantity of CD34(+) PGCs per hematopoiesis (cellularity) in the CML bone marrow before treatment. Independently of treatment modalities and presentation of clinical findings nonresponding patients were generally characterized by a higher amount of progenitors in the initial biopsy specimens. Furthermore, calculation of the CD34(+) cell growth index showed a significant and rapid progression in nonresponding patients and in those developing an accelerated or blastic phase during therapy. This feature was prominently expressed following IFN treatment and related to a failing regeneration of nucleated erythroid precursors. In patients with a myelofibrotic bone marrow at onset no differences in the number of CD34(+) PGCs were recognizable in the pretreatment biopsies. This finding contrasted a significant and gradual change in progenitor cell frequency under treatment and evolving myelofibrosis. Opposed to HU therapy, the latter feature was explicitly detectable in the IFN group. In conclusion, the incidence of CD34(+) PGCs in the CML bone marrow reflects therapeutic efficacy. By demonstrating a significant relationship between fiber content and quantity of CD34(+) cells during treatment, experimental findings concerning the complex functional interactions between the fibrous stroma compartment and progenitor cell differentiation and proliferation are elucidated.

Antigens, CD34↗
PubMed2001

Immunoreactivity of monoclonal antibody BW835 represents a marker of progression and prognosis in early gastric cancer.

The Thomsen-Friedenreich (TF) antigen is a well-known human pan-carcinoma antigen. It represents a carbohydrate core disaccharide (Gal beta 1-3GalNAc) which is predominantly bound to mucin peptide cores. Its immunoreactivity depends on changes in glycosylation which lead to a reduction in the carbohydrate chain length and the exposure of core carbohydrates. In the present study, we investigated 208 gastric adenocarcinomas with respect to their immunohistochemical reactivity applying two monoclonal antibodies (MAbs). MAb specifically detecting TF antigen (A78-G/A7) and MAb BW835 were included. The latter reacts with a certain glycoform of the MUC1 peptide core, characterized by core-type glycans like TF. A78-G/A7 epitopes were detected in 68.8% and BW835 epitopes in 57.7% of the carcinomas. BW835 immunoreactivity correlated with the presence of lymph node metastases. Both A78-G/A7 and BW835 staining were significantly stronger in tubular/papillary cancer (WHO classification) and intestinal-type cancer according to Laurén. In univariate survival analyses of all patients studied, BW835 immunoreactivity was a marker of an unfavorable prognosis (p < 0.05). The presence of A78-G/A7 and BW835 epitopes exerted a negative effect on the subgroup of pTNM stage I carcinomas. These results indicate that TF and MUC1-TF immunoreactivity defines a 'high-risk' subgroup of stage I patients in gastric cancer.

Adenocarcinoma↗
PubMed2001

Bone marrow engraftment: histopathology of hematopoietic reconstitution following allogeneic transplantation in CML patients.

Following myelo-ablative treatment and allogeneic bone marrow transplantation (BMT) in chronic myelogenous leukemia (CML) histopathological features assumed to exert a significant impact on engraftment have been rarely investigated systematically. This review is focused on immunohistochemical and morphometric techniques involving nucleated erythroid precursors, resident macrophages and their various subsets, megakaryocytes and finally argyrophilic (reticulin-collagen) fibers. Regarding standardized intervals of examination in the postgraft sequential trephine biopsies a pronounced reduction in cellularity was obvious and accompanied by a decrease in the quantity of erythro- and megakaryopoiesis. A significant correlation between the number of erythroid precursors and CD68+-macrophages could be determined in the areas of regenerating hematopoiesis. This finding is in keeping with the important functional role of the centrally localized mature macrophages during erythropoiesis. A relevant pretransplant reduction of the red cell lineage and an early to advanced reticulin fibrosis were correlated with a low hemoglobin level (anemia) and splenomegaly and furthermore associated with a significant delay to reach transfusion independence. This result was supported by corresponding findings in biopsy specimens performed shortly after day 30 following BMT (standard interval for assessment of engraftment). Samples revealed an enhancement of fiber density and a conspicuous decrease in the amount of erythropoiesis in the small fraction of patients who did not conform with the usually accepted criteria for successful hematopoietic reconstitution. Considering the compartment of histiocytic reticular cells the recurrence of Pseudo-Gaucher cells (PCGs) in the engrafted donor marrow was remarkable and most prominently expressed in the first two months following BMT. This feature was presumed to be functionally linked with a pronounced degradation of cell debris in the sequel of myelo-ablative therapy (scavenger macrophages). According to planimetric measurements in the postgraft bone marrow the atypical dwarf-like CD61+-megakaryocytes characteristic for CML disappeared. On the other hand, normalization of megakaryocyte size and nuclear lobulation were absent in sequential examination of the few patients developing a leukemic relapse. In a number of patients with manifest myelofibrosis at onset, an initial regression after BMT was followed by an insidiously occurring retrieval which was concentrated on the areas of reconstituting hematopoiesis. Similar to its relevant pretransplant association the postgraft reappearance of myelofibrosis was significantly correlated with the quantity of CD61+-megakaryocytes. Altogether a number of histological features in the pre-and postgraft bone marrow exhibited significant correlations with each other and thus indicated functional relationships. Moreover, quantity of erythropoiesis and amount of reticulin fibers (myelofibrosis) exerted a significant impact on engraftment status.

Animals↗
PubMed2001

The value of bone marrow histology in differentiating between early stage Polycythemia vera and secondary (reactive) Polycythemias.

BACKGROUND AND OBJECTIVES: The diagnostic criteria of the Polycythemia Vera Study Group (PVSG), although generally acknowledged as the gold standard for establishing a diagnosis of polycythemia vera (PV), do not consider bone marrow features. It may, therefore, be speculated that initial-early stages of PV are overlooked. In this retrospective study we tried to investigate whether bone marrow morphology of patients with an only borderline to slight increase in hemoglobin/hematocrit not conforming with the postulates of the PVSG enabled a clear-cut differentiation between PV and secondary (reactive) polycythemias (SP). DESIGN AND METHODS: From a series of 348 patients with a borderline to pronounced erythrocytosis and representative pre-treatment bone marrow trephine biopsies a cohort of 86 cases was selected showing only a borderline increase in hemoglobin (males < 18.5 g/dL, females < 16.5 g/dL). Biopsies and clinical records were evaluated independently and following histologic and clinical work-up a straightforward consensus was reached. The diagnostic impact of histologic findings was tested by means of discriminate analysis of 20 standardized morphologic features based on histochemical and immunohistochemical staining techniques. RESULTS: Bone marrow histopathology in 47 patients diagnosed as having SP was characterized by a minimal to slight increase in cellularity with predominance of the erythroid lineage. Neutrophil granulocytopoiesis was prominent and left-shifted and small to medium-sized megakaryocytes without maturation defects were scattered throughout the bone marrow. There was an increased number of eosinophils, marked perivascular plasmacytosis, histiocytic reticular cells with accumulated cell debris and many iron-laden macrophages. Contrasting this appearance in SP our 39 patients with initial-early stage PV revealed a hypercellular bone marrow with trilineage proliferation (pan-myelosis) showing confluent sheets of erythropoiesis and loose clusters of megakaryocytes. Megakaryocytopoiesis was characterized by a pleomorphous appearance, i.e. giant cells were lying adjacent to small ones, but lacked an obvious cytologic abnormality. There was usually no prominent inflammatory reaction of the interstitial compartment. In ten patients lymphoid nodules were found, but no conspicuous iron deposits and in six patients a borderline to minimal increase in reticulin fibers was present. Following stepwise discriminate analysis of histologic features a set of parameters emerged including increase in megakaryocyte size, perivascular plasma cells, overall bone marrow cellularity and cellular debris. This pattern exerted a significant impact on separation (Wilks' lambda statistics = 0.110, p < 0.0001) of early stage PV from SP. Most patients with SP had an underlying bronchopulmonary condition, frequently associated with heavy smoking or rarely renal pathology. In addition to the histopathologic features, splenomegaly, thrombocyte count, LDH, LAP and erythropoietin levels proved to be different in the two groups of patients. INTERPRETATION AND CONCLUSIONS: Initial-early PV is characterized by a specific pattern of bone marrow histopathology. Clinical features of distinctive impact include splenomegaly, thrombocyte count, LDH, LAP and in particular erythropoietin level. Taking these clinical and histologic findings into consideration, reactive-secondary causes of polycythemia (SP) are clearly distinguishable from autonomous ones (PV).

Adult↗
PubMed2000

Thomsen-Friedenreich antigen presents as a prognostic factor in colorectal carcinoma: A clinicopathologic study of 264 patients.

BACKGROUND: Up to now, the expression of the tumor-associated Thomsen-Friedenreich (TF) antigen in colorectal carcinoma has not been thoroughly investigated with particular emphasis on its correlation with established clinicopathologic characteristics and classifications as well as its prognostic relevance. METHODS: Formalin fixed, paraffin embedded specimens from 264 patients with colorectal carcinoma were stained using an avidin-biotin complex-peroxidase assay. As primary monoclonal antibodies (MAbs), A78-G/A7, which binds to TFalpha and TFbeta antigen irrespective of its carrier, and BW835, which detects TFalpha on MUC1 repeat peptide, were applied. RESULTS: MAbs A78-G/A7 and BW835 labeled 64.8% and 58. 0%, respectively, of carcinomas. None of the binding patterns correlated with gender, tumor localization, or growth type. Only BW835 reactivity exhibited a significant correlation with increasing pTNM staging and histologic grading. Staining of the MAb A78-G/A7 was significantly stronger in carcinomas that contained a mucinous component. In univariate survival analysis, in addition to pTNM staging and histologic grading, reactivity with A78-G/A7 as well as BW835 were significantly correlated with lower survival probability. Multivariate analysis according to the Cox proportional hazards model revealed only pTNM staging, histologic grading, and A78-G/A7 staining to be independent prognostic factors. CONCLUSIONS: According to these results, TF disaccharide represents a cancer-associated antigen in colorectal carcinoma that exhibits qualities of a prognostic marker. As demonstrated by BW835 staining, it is obviously coexpressed with MUC1 peptide core in a great number of cases. These results suggest that TF, in addition to MUC1, might also serve as a useful target antigen in the treatment of patients with colorectal carcinoma.

Adenocarcinoma↗
PubMed2000

Prognostic impact of p21/waf1/cip1 in colorectal cancer.

In addition to the tumor suppressor gene p53, Cyclin Dependent Kinases (CDK) are well known to influence the cell cycle in normal human tissues and various neoplasias as well. The purpose of our present study was to evaluate the expression of the CDK-inhibitor p21/waf1/cip1 in colorectal cancer with special emphasis on the prognostic impact. Between 1985 and 1991, 294 patients (median age, 65 years) underwent surgical operative therapy for colorectal cancer. Formalin-fixed and paraffin-embedded tumor specimens were investigated. For immunohistochemistry the Catalysed Reporter Deposition (CARD) technique was performed. The survival probability was calculated and possible prognostic risk factors were tested using multivariate analysis. The p21/ waf1/cip1 staining pattern was positive in 197 (67%) specimens and negative in 97 (33%) samples. No significant correlation could been calculated between p21/waf1/cip1 expression and other variables such as age, sex, WHO-Classification, localisation, grading, TNM-classification or UICC-stage. Patients with a positive staining reaction had a significantly better survival (p < 0.0052). Moreover, p21/waf1/cip1 was shown to be an independent prognostic parameter by multivariate analysis (p < 0.022). In contrast with these findings, the p53 tumor status had no impact on survival. P21/ waf1/cip1 appears to be an independent prognostic parameter in colorectal cancer and is associated with a favorable survival. This feature may be related to a cell cycle arrest in the G1 phase induced by p21/waf1/cip1, resulting in lower tumor cell proliferative activity.

Aged↗
PubMed2000

[Reactive lymphoid nodule or malignant lymphoma. A brief guideline for the differential diagnosis of bone marrow infiltrates in non-Hodgkin lymphomas].

Differentiation of focal or extended lymphoid bone marrow infiltrates presents a diagnostic challenge and therefore warrants systematic evaluation of those features which affect this. One of the basic requirements is an appropriate technique of processing the bone marrow specimens. This includes the possibility of enzyme evaluation (naphthol-AS-D-chloroacetate esterase) and immunohistochemistry (set of monoclonal antibodies) and comparison with the corresponding lymph node histology. A number of histological parameters have emerged with a distinctive property for distinguishing between reactive focal lymphoid aggregates and malignant lymphomas. Amongst these the pattern of infiltrates, i.e., histotopography (subcortical infiltrates, paratrabcular-endosteal localization, margination, tandem-like extension between adipocytes and cribriform appearance), content of reticulin fibers, cytology (small lymphocytes versus large blast cells) and, finally, immunohistochemistry (monoclonal versus polyclonal expression of cytoplasmic immunoglobulins, uniform versus mixed population of B or T lymphocytes) are most important. In conclusion, synoptic consideration of several parameters, in particular histotopography and immunohistochemistry provides a most promising approach to differentiate neoplastic from reactive lymphoid lesions in the bone marrow.

Antibody Formation↗
PubMed2000

[ Polyglobuly versus polycythemia vera].

Differentiation of an elevated hemoglobin/hematocrit level warrants not only the determination of relevant laboratory values, including erythropoietin, but also an elaborate evaluation of bone marrow histopathology. Particularly in the initial stages of polycythemia vera (PV), when not all stringent clinical criteria are completely fulfilled, a more refined analysis of morphological features helps to distinguish autonomous (PV) from spurious or secondary erythrocytosis - polyglobuly (PG). PV is characterized by a panmyelosis, i.e., a trilinear proliferation of all cell lineages, whereas in PG erythropoiesis predominates. Megakaryopoiesis exerts a significant impact on differentiation, because in PV there is a conspicuous grouping associated with a strikingly expressed pleomorphous appearance. This peculiar feature implicates assemblies of small- to medium-sized megakaryocytes lying adjacent to giant cells with extensively lobulated, staghorn-like nuclei. A further discriminating parameter is presented by the interstitial lesions frequently occurring in PG. These, according to the usually underlying inflammatory cause (chronic bronchitis-recurrent bronchopneumonias), include iron-laden macrophages, a prominent perivascular plasmacytosis, phagocytosis of cell debris by histiocytic reticular cells and often an in- crease in the number of eosinophils. Comparable findings are not, or only to a minor ex-tent, detectable in PV. In conclusion, by regarding hematopoiesis and the myeloid stroma initial stages of PV may be definitively distinguished from PG.

Bone Marrow↗
PubMed2000

[Thrombocytosis versus thrombocythemia--differential diagnosis of elevated platelet count].

Differentiation of an elevated, repeatedly determined platelet count (> or =500x10(9)/l) includes the discrimination between reactive causes generated by a variety of underlying conditions and a neoplastic myeloproliferative disorder (CMPD). In addition to clinical findings, the evolution of laboratory data during follow-up and histology of the bone marrow exerts a significant diagnostic impact. Characteristic features are not only expressed by hematopoiesis, but also by the myeloid stromal compartment. While the megakaryocyte-rich subtype of chronic myeloid leukemia (CML) and the 5q(-) syndrome (MDS) are dominated by abnormal micromegakaryocytes, in polycythemia vera (PV) this cell lineage reveals a pleomorphous appearance. In essential thrombocythemia (ET), a prevalence of giant megakaryocytes with deeply lobulated (staghorn-like) nuclei may be encountered. A clear-cut discrimination of ET from early (hypercellular) stages of idiopathic (primary) myelofibrosis (IMF) presenting with thrombocythemia becomes possible, provided the conspicuous atypical features of megakaryopoiesis characterizing the latter entity are taken into account. Moreover, CML displays a predominance of the granulocytic lineage whereas PV shows a panmyelosis or trilineage proliferation, involving erythropoiesis, in particular. In contrast, erythropoiesis is markedly reduced in CML and to a lesser degree also in IMF. In CMPDs extreme values of iron deposits may be found, ranging from a total lack (PV) to minor amounts (CML) and a normal staining reaction (ET). Similar results are exhibited regarding reticulin fibrosis, which is usually not present in ET, rarely observed in PV and detectable to a variable degree in CML and IMF.

Diagnosis, Differential↗
PubMed2000

[Histologic and hematological findings in CML. A comparative immunohistochemical-morphometric and clinical study on bone marrow biopsies from 604 patients derived from two institutes of pathology (Cologne/Freiburg)].

An immunohistochemical and morphometric study was performed on bone marrow biopsies in 604 patients with chronic myelogenous leukemia (CML) to compare morphological and clinical features and to evaluate effects of interferon (IFN) and chemotherapy. Following morphometry significant correlations were calculated between number of CD61(+) megakaryocytes, including their precursors with fiber density. This finding is in line with the close functional relationship between megakaryopoiesis and fibroblasts regarding the complex pathomechanism of myelofibrosis. The latter was observed in about 28% of patients already at diagnosis. In a similar way, the frequency of CD68(+) macrophages was correlated with the amount of Ret40f(+) nucleated erythroid precursors, implicating an involvement of this cell lineage in iron turnover, hemoglobin synthesis, and degradation of the expelled nuclei from normoblasts. The (alpha-D-galactosyl residue-expressing) Pseudo-Gaucher cells were detectable in 30% of pretreatment specimens. Moreover, significant associations were calculable between reduction in erythropoiesis or increase in fibers with clinical features such as hemoglobin level, percentages of myelo- and erythroblasts in the peripheral blood, and spleen size. These variables are in keeping with more advanced stages of CML. Based on our morphometric evaluations, a classification into three different histological subgroups: granulocytic, megakaryocytic, and myelofibrotic was carried out. This simplified staging system was correlated with corresponding sets of hematological data. Sequential biopsies in 173 patients with monotherapy by IFN, hydroxyurea (HU), or busulfan (BU) revealed a fibrogenic effect of IFN in contrast to a fiber-reducing property of HU. The dynamics of myelofibrosis and changes of major cell lineages during treatment were readily demonstrable by calculating corresponding indices. These included the ratios between quantitative differences of corresponding variables at repeated examinations and time. Thus, in patients with complete hematological remission following IFN administration, regeneration of erythropoiesis was found to be accompanied by an increase in the total number of CD68(+) macrophages, including activated subpopulations. Histological subgroups showed a transition from a (nonfibrotic) granulocytic and megakaryocyte pattern to the myelofibrotic subtype in about 40% of patients. This change was opposed to a numerical reduction in the myelofibrotic subtype which occurred in 17 patients (36%), but predominantly in those under HU therapy. In conclusion, the striking heterogeneity of bone marrow features in CML warrants a careful morphological evaluation of trephine biopsies and appropriate means of processing to achieve relevant correlations with clinical data and, thus, allows a more elaborate insight into the dynamics of the disease process.

Biopsy↗
PubMed2000

[Apoptosis and proliferation in the bone marrow of chronic myeloproliferative disorders--biological and prognostic importance].

Apoptosis and proliferation are important regulators of normal development and homeostasis in the bone marrow. Therefore, dynamics of hematopoiesis is mainly defined by these two parameters. However, since only few data are available from previous studies, we performed a retrospective analysis to elucidate some aspects of this complex pathomechanism. A total of 400 patients with chronic myeloproliferative disorders (CMPDs) and corresponding reactive bone marrow lesions were enrolled into this study. Apoptosis was detected in bone marrow tissue by the ISEL-technique and topoisomerase II alpha expression was demonstrated by the monoclonal antibody Ki-S1. Furthermore, by determination of the proliferating-cell nuclear antigen labeling (PCNA) index, we were able to calculate the proportion of cells in the G2/M phase, because both nuclear antigens are expressed in different phases of the cell cycle. Patients with IMF, PV, and ET revealed a normal range of apoptosis, whereas in chronic myeloid leukemia (CML) a significant increase could be observed. On the other hand, IMF and PV were characterized by a raised proliferative activity. Dynamics of hematopoiesis was assessed by calculation of the so called hematopoietic turnover index. In CML and reactive lesions no alterations of this parameter were detectable, but IMF and PV showed a significant increase. Survival analysis disclosed a relevant worsening of life expectancy for patients with reduced apoptosis and proliferation. In conclusion, our in-situ results confirm and extend previous experimental data on hematopoietic cell kinetics. In this context, a greater regenerative capacity of hematopoiesis may be reflected by an increased rate of apoptosis and/or proliferation and therefore is associated with a more favorable outcome.

Antibodies, Monoclonal↗
PubMed2000

[Prognostic factors and survival in chronic myeloproliferative disorders].

The broad spectrum of clinical and hematological as well as histomorphological findings at diagnosis of chronic myeloproliferative disorders (CMPDs) is significantly associated with prognosis. However, in this context the impact of bone marrow histology is still being controversially discussed. This feature applies to CML in particular. Therefore, risk classification is mainly based on clinical data. In order to evaluate the predictive value of bone marrow morphology we performed a retrospective study on a total of 1023 patients with CMPDs. Relative survival rates and a disease-specific loss of life expectancy were calculated to adjust the age- and gender-specific mortality in older patients. Patients with chronic myeloid leukemia (CML) showed an average life expectancy of 5 years, with significantly longer survival times under interferon treatment. In contrast, the ET group did not disclose any relevant reduction in life expectancy. Initial bone marrow fibrosis and a reduction in erythropoiesis were the most important prognostic features in CML. Furthermore, Pseudo-Gaucher cells indicated a favorable outcome in the cohort of patients receiving chemotherapy. On the other hand, peripheral myelo- and erythroblasts were correlated with a worsening in survival. Regarding IMF, a simplified multivariate risk score was constructed, including age, hemoglobin level, platelet and leukocyte counts, and a leuko-erythroblastic blood picture as most important variables. The three risk groups derived showed significantly different survival patterns, but in this calculation bone marrow histology exerted no major influence on survival. On the other hand, initial (prefibrotic) stages of IMF revealed a better prognosis. In conclusion, our results underline the importance of bone marrow morphology in CMPDs, since significant correlations with patients' outcome were calculated. Particularly in CML, myelofibrosis and reduction of erythropoiesis were associated with survival and, thus, must be regarded as important predictive and independent parameters.

Adult↗
PubMed2000

Macrophages and their subpopulations following allogenic bone marrow transplantation for chronic myeloid leukaemia.

A morphometric and immunohistochemical study was performed on 354 bone marrow trephine biopsies derived from 126 patients with chronic myeloid leukaemia (CML) before and after allogeneic bone marrow transplantation (BMT). The purpose of this investigation was to evaluate the macrophage population, including several subsets and their dynamics in the posttransplant period. In addition to the total CD68+ resident (mature) macrophages the so-called activated fraction identified by its capacity to express alpha-D-galactosyl residues, the pseudo-Gaucher cells (PGCs) and the iron-laden histiocytic reticular cells were also considered. Following immuno- and lectin-histochemical staining morphometric analysis was carried out on sequential postgraft bone marrow specimens at standardized intervals. Compared to the normal bone marrow and calculated per haematopoiesis (cellularity) an overall decrease of about 40-50% in the quantity of CD68+ macrophages and the BSA-I+ subpopulation was detectable in the early posttransplant period (9-45 days after BMT). Noteworthy was the temporal recurrence of PGCs in the engrafted bone marrow, which was not associated with a clonally transformed cell population or leukaemic relapse. Reappearance of postgraft PGCs was most prominent in the first 2 months after BMT. This conspicuous feature was presumed to be functionally associated with a pronounced degradation of cell debris following pretransplant myelo-ablative therapy (scavenger macrophages). Evidence for an activation of the BSA-I+ macrophage subset was derived from the identical carbohydrate-binding capacity shown by the PGCs. In the regenerating haematopoiesis shortly after BMT a significant correlation between the number of BSA-I+ macrophages and erythroid precursor cells was determinable. This result implicates a close functional relationship between postgraft reconstitution of erythropoietic islets and centrally localized activated macrophages. In conclusion, findings emerging from this study included the reappearance of PCGs in the engrafted bone marrow independently of a leukaemic relapse and the significant association of the activated BSA-I+ macrophage subset with the recovery of erythropoiesis.

Adult↗
PubMed2000

Selectins (CD62L, CD62P) and megakaryocytic glycoproteins (CD41a, CD42b) mediate megakaryocyte-fibroblast interactions in human bone marrow.

Previous in vitro studies are in keeping with the finding that isolated and enriched megakaryocytes attach to bone marrow fibroblasts and generate an increased growth of these cells. This process was assumed to depend on a close spatial relationship between both cell types which supports the paracrine effect of platelet-derived growth factor (PDGF) and transforming growth factor (TGF)-beta1. Moreover, adhesion molecules including beta1 integrin receptors and fucosylated structures were determined to play an important role in these complex interactions. However, up to now the influence of megakaryocyte expressed glycoproteins CD41a and CD42b in these processes was not investigated. In addition, the role of megakaryocytic CD62P and also of CD62L, both adhesion molecules of the selectin group, could also be of interest. Following isolation and enrichment of bone marrow megakaryocytes and fibroblasts, both cell populations were characterized regarding their expression of these factors by applying immunocytochemical techniques. Additionally, their influence on adhesion of megakaryocytes to fibroblasts as well as fibroblast growth was evaluated by comparative megakaryocyte-fibroblast co-cultures and inhibition studies using specific monoclonal antibodies (mabs). Fibroblast monocultures served as controls. In these experiments, selectin-specific antibodies significantly reduced megakaryocyte attachment to fibroblast feeder layers and fibroblast growth in the co-cultures. The effect of CD41a and CD42b specific antibodies was limited to megakaryocyte-dependent fibroblast growth. These results elucidate the involvement of the selectins CD62P and CD62L in the basal activation of megakaryocytes inducing their attachment to bone marrow fibroblasts. In contrast, the megakaryocyte glycoproteins CD41a and CD42b exert their effect on the megakaryocyte dependent fibroblast growth. Altogether, it is tempting to speculate that the various interactions of these mediators reflect certain steps in the complex pathomechanisms causing the evolution of (reactive) myelofibrosis in hematopoietic neoplasias accompanied by megakaryocytic proliferation.

Bone Marrow↗
PubMed2000

Visualization of carbohydrate-binding molecules expressed by myelomono- and erythropoietic cells derived from human bone marrow: an immunoenzymatic double-staining study.

Interactions between human haematopoietic and bone marrow stromal cells are governed by complex carbohydrate-mediated adhesion processes. In order to evaluate corresponding carbohydrate-binding sites on human myelo- and erythropoietic cells which were able to react with mono- or oligosaccharides, we established an immunocytochemical double-staining assay. In a first step, cell lineages were visualized using Lewis(x) (CD15) or glycophorin C-specific monoclonal antibodies. The second step included polyacrylamide-conjugated carbohydrate structures. According to our results, the carbohydrate-binding potential of granulopoietic cells increased during the process of maturation, contrasting a reduction of carbohydrate-binding sites on erythroid precursor cells during differentiation. With respect to previous in vitro studies, these findings shed some light on certain aspects of bone marrow homing as well as on the trafficking of mature cellular elements into circulation. It is tempting to speculate that carbohydrate-mediated adhesion mechanisms may be involved in the various functional defects of progenitor cells in chronic myelogenic leukaemia, especially regarding their complex interactions with the marrow microenvironment.

Binding Sites↗
PubMed2000

Therapy-related changes of CD20+ and CD45RO+ lymphocyte subsets in chronic myeloid leukemia (CML): an immunohistochemical and morphometric study on sequential trephine biopsies of the bone marrow.

Little information exists about the amount of CD45RO+-T- and CD20+-B-lymphocytes in the bone marrow of patients with Philadelphia chromosome-positive chronic myelogenous leukemia (Ph1+-CML) at presentation or regarding corresponding changes during therapy. On the other hand, quantification of this cell compartment seems to be imperative for two reasons: first, the presumed association of immunocompetent lymphocyte subsets in the expansion of the leukemic cell clone; and second, a speculated relationship with the complex generation of myelofibrosis. Therefore, an immunohistological and morphometric study was performed on 219 representative trephine biopsies of the bone marrow derived from 70 patients with repeated examinations during the course of Ph1+-CML. For the identification of the different lymphocyte populations, the monoclonal antibodies UCHL-1 (CD45RO) and L26 (CD20) were applied on formaldehyde-fixed and decalcified specimens. In comparison to a control group and calculated per hematopoietic cells, the CML bone marrow showed about a 50% decrease in the total amount of lymphocytes. Determination of CD45RO+ and CD20+ subsets revealed a significant enhancement during treatment. Because of the different intervals (range, 10 to 25 mo) between first and last biopsy in the various therapeutic groups, results had to be modified by considering dynamic features. This calculation included changes of the lymphocyte subpopulations related to time. Contrasting the CD45RO+ lymphocytes, a relevant increase in the CD20+ subset could be observed after interferon-a treatment or corresponding combination regimens. No significant correlations were found between fiber density at onset (first biopsy) or development of fibrosis and lymphocyte proliferations in the course of CML. Our results are in keeping with the finding that a proper immune response consistent with an increased lymphocyte growth seems to be associated with a regression of the clonally-transformed cell population. Opposed to a repeatedly discussed pathomechanism, we failed to demonstrate any quantitative relationships between the extent of lymphocyte proliferations and occurrence or progression of myelofibrosis.

Adult↗