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L B Schwartz

Publications and source records attributed to L B Schwartz.

At least 19 recordsLinked to original sources
PubMed2006

Enumeration and immunohistochemical characterisation of bone marrow basophils in myeloproliferative disorders using the basophil specific monoclonal antibody 2D7.

BACKGROUND: Basophils are highly specialised granulocytes that express a unique profile of antigens and increase in myeloproliferative disorders (MPD). In chronic myeloid leukaemia (CML), basophilia is a diagnostic and prognostic determinant. So far, however, no reliable approach for routine detection and enumeration of bone marrow basophils has become available. OBJECTIVE: To detect and enumerate basophils in bone marrow sections in patients with CML and other MPD. METHODS: The anti-basophil antibody 2D7 was applied to paraffin embedded bone marrow sections from normal/reactive subjects (n = 31), patients with CML (chronic phase, n = 37; accelerated phase, n = 9), and other MPD (chronic idiopathic myelofibrosis (CIMF), n = 20; polycythaemia vera (PV), n = 20; essential thrombocythaemia (ET), n = 20; indolent systemic mastocytosis (ISM), n = 7). RESULTS: As assessed by serial section staining, 2D7(+) cells were found to co-express myeloperoxidase, histidine decarboxylase, CD9, and CD43, but did not express B cell or T cell restricted antigens. 2D7(+) bone marrow cells were found to increase in CML compared with normal/reactive bone marrow and other MPD (median numbers of 2D7(+) cells/mm(2): CML, 33; normal/reactive bone marrow, 6; CIMF, 10; PV, 6; ET, 5; ISM, 3; p<0.05). The highest basophil counts were recorded in accelerated phase CML (115/mm(2)). CONCLUSIONS: A novel immunohistochemical procedure has been established for basophil detection in normal bone marrow and MPD. This approach should help in the quantification of bone marrow basophils at diagnosis and during anti-leukaemic treatment.

Adult↗
PubMed2006

The tryptase positive compact round cell infiltrate of the bone marrow (TROCI-BM): a novel histopathological finding requiring the application of lineage specific markers.

AIMS: Compact tryptase-positive round cell infiltrates of the bone marrow (TROCI-BM) are very rare histopathological findings and may pose challenging problems with regard to the cell type involved (either mast cells or basophilic granulocytes) and the exact diagnosis. METHODS: A selected panel of immunohistochemical markers against mast cell and basophil related antigens, including CD25, CD34, CD117/Kit, and the 2D7 antigen (which is found only in basophilic granulocytes) on a total of 410 routinely processed bone marrow biopsy specimens (including 88 cases of systemic mastocytosis (SM), 20 cases of chronic myeloid leukaemia (CML), 92 cases of myeloid neoplasms other than CML, and 210 controls with normal/reactive bone marrows). RESULTS: In total, 17 cases with TROCI-BM could be identified: 11 SM (including two cases of well-differentiated SM and two mast cell leukaemias; MCL), 2 myelomastocytic leukaemia (MML), 2 CML with excess of basophils (secondary basophilic leukaemia (CMLba)), and 2 tryptase positive acute myeloid leukaemia (AML). Regarding the cell types involved, TROCI-BM cells were found to express CD117/Kit in all cases of SM and MCL. In MML and tryptase postitive AML, TROCI-BM cells were found to coexpress CD34 and Kit. The basophil specific antigen 2D7 was only detected in CD34/Kit negative TROCI-BM cells in two patients with CMLba. The activating point mutation D816V was detected in 8/11 patients with SM but not in any of the other haematological malignancies. CONCLUSIONS: In summary, a total of six rare myeloid neoplasms may present with a novel immunohistochemical phenomenon tentatively termed TROCI-BM.

Adult↗
PubMed2004

Heparin-induced recurrent anaphylaxis.

BACKGROUND: Heparin-related immediate-type hypersensitivity reactions like urticaria, angio-oedema or bronchospasm are very rare, and only a few cases of anaphylaxis-like responses because of heparin have been described. However, the mechanisms underlying these reactions and the role of mast cells in their pathogenesis have not been elucidated. OBJECTIVES: We report a patient with end-stage renal disease who presented with recurrent anaphylaxis after receiving heparin during haemodialysis. The underlying aetiology was obscured by the initiation of haemodialysis with its known anaphylactic-like side-effects. The diagnosis of hypersensitivity to heparin was confirmed by the clinical picture, positive skin tests and elevated serum tryptase levels. MATERIALS AND METHODS: We performed prick and intradermal skin tests with heparin, enoxaparin and danaparoid heparinoid. Total and mature tryptase levels were measured in serum by ELISAs at 1, 24 and 36 h following the reaction. RESULTS: An elevated mature tryptase level was found at 1 h, which returned to normal levels at 24 and 36 h. A high total tryptase level was detected at 1 h, but remained somewhat elevated at 24 h. Prick tests were negative with the three compounds. Intradermal skin tests with heparin and enoxaparin were both positive, while with danaparoid negative. Following negative skin test results, danaparoid was used as an anticoagulant during dialysis for the next 3 years without any adverse effects. CONCLUSIONS: In conclusion, we report the first case of heparin-induced anaphylaxis confirmed by an elevated level of mature tryptase in serum. Following skin tests, the patient was treated with danaparoid during haemodialysis sessions three times a week without any adverse effects. Because of increasing use of heparin in daily medical practice, physicians should be aware of possible immediate hypersensitivity reactions to this medication and know how to diagnose and treat them.

Anaphylaxis↗
PubMed2004

Batroxobin reduces intracellular calcium concentration and inhibits proliferation of vascular smooth muscle cells.

BACKGROUND: Batroxobin (BX), a serine protease used in defibrinogenation and thrombolysis, also has an effect on c-fos gene and growth factor. This study attempted to determine the effects of BX on the proliferation of vascular smooth muscle cells (VSMCs) and calcium metabolism. METHODS: VSMCs were treated with BX at concentrations of 0.1, 0.3, or 1.0 mmol/L and cell numbers were determined at 0, 24, 48, and 72 hours. Intracellular calcium concentration ([Ca2+]i) was measured using direct fluorescence methods. RESULTS: BX was found to suppress proliferation of VSMCs in a dose-dependent fashion with inhibition rates of 18% and 31% by 48 and 72 hours, respectively. In addition, BX decreases basal [Ca2+]i significantly. The basal level in untreated cells was 162.7 +/- 33.8 nmol/L, and decreased to 131.5 +/- 27.7 nmol/L, 128.3 +/- 28.5 nmol/L, and 125.6 +/- 34.3 nmol/L with the three concentrations of BX, respectively. Noradrenaline (NE)-induced [Ca2+]i stimulation was also attenuated by BX (0.1 mmol/L BX, 20% +/- 8% inhibition; 0.3 mmol/L BX, 54% +/- 11% inhibition; 1.0 mmol/L BX, 62% +/- 15% inhibition). The ability of NE to stimulate [Ca2+]i was attenuated in cultures in Ca(2+)-free medium, as was the ability of BX to blunt NE-induced stimulation. CONCLUSION: These findings demonstrate that BX can effectively inhibit proliferation of VSMCs, probably by blocking the release and uptake of Ca2+, thus influencing [Ca2+]i.

Animals↗
PubMed2002

Characterization of 'adult-type' mast cells derived from human bone marrow CD34(+) cells cultured in the presence of stem cell factor and interleukin-6. Interleukin-4 is not required for constitutive expression of CD54, Fc epsilon RI alpha and chymase, and CD13 expression is reduced during differentiation.

BACKGROUND: In vitro-derived human mast cells exhibit different properties, depending in part on the source of progenitor cells. Most investigations have used fetal liver, cord blood or peripheral blood. Few have used adult bone marrow. OBJECTIVE: Human mast cells derived in vitro from the CD34(+) progenitors in bone marrow and cord blood that had been cultured with recombinant human stem cell factor (rhSCF) and recombinant human interleukin-6 (rhIL-6) were compared. METHODS AND RESULTS: After 12 weeks of culture, nearly all of the cells were mast cells, and nearly all of these had cytoplasmic granules containing both tryptase and chymase (MCTC type), stained metachromatically with acidic toluidine blue, and expressed CD117 on the cell surface. Both tryptase protein and mRNA were detected by two weeks of culture. Chymase mRNA and protein were detected at 4 weeks but not at 2 weeks of culture. By 12 weeks, chymase content per cell, measured by ELISA, was significantly higher (P < 0.05) in human bone marrow-derived mast cells (HBMMC) (5.6 +/- 0.9 pg) than in cord blood-derived mast cells (CBMC) (2.4 +/- 0.9 pg), whereas histamine and tryptase levels were not significantly different. Of the cluster designations tested, CD29, CD49d, CD51 and CD61 were strongly expressed on HBMMC. CD54 and Fc epsilon RI alpha also were expressed constitutively. Approximately half of CD34-sorted cells at day 0 were CD13(+) and this diminished as mast cell maturation occurred. Electron microscopy revealed that 12-week-old HBMMC had many secretory granules that contained spherical electron dense cores surrounded by electron lucent space, consistent with previous reports of immature MCTC cells developing in vivo. CONCLUSIONS: CD34(+) progenitors of human bone marrow are a rich source of mast cell progenitors capable of expressing granule and surface markers of mature mast cells in the presence of rhSCF and rhIL-6.

Antigens, CD↗
PubMed2002

Serum tryptase measurements in patients with myelodysplastic syndromes.

Abnormal differentiation and maturation of hemopoietic cells are characteristic features of myelodysplastic syndromes (MDS). Tryptases (alpha- and beta-type) are lineage-restricted serine proteases primarily expressed in mast cells (MC). We have analyzed expression of tryptase in 89 de novo MDS patients (refractory anemia (RA), n = 30; RA with ringed sideroblasts (RARS), n = 21; RA with excess of blasts (RAEB/RAEB-t), n = 27; chronic myelomonocytic leukemia (CMML), n = 11). Serum levels of total tryptase (alpha - protryptase + beta - tryptase) were measured by FIA. The numbers of tryptase+ cells were determined in paraffin-embedded bone marrow (bm) sections by immunohistochemistry and morphometry. In healthy individuals, serum total tryptase levels ranged between < 1 and 15 ng/ml (5.6 +/- 2.8 ng/ml). Tryptase levels of > 20 ng/ml were detected in 5/22 patients with RA (22.7%), 4/17 with RARS (23.5%), 0/16 with RAEB/RAEB-t, and 3/8 with CMML (37.5%). Thus, serum tryptase concentrations were higher in RA (16.6 +/- 14.3 ng/ml), RARS (12.9 +/- 8.2), and CMML (16.5 +/- 7.6) compared to RAEB/-t (8.7 +/- 3.8). By morphometry, elevated numbers of tryptase+ bm cells were detected in all MDS groups (RA: 139 +/- 131; RARS: 118 +/- 98; RAEB/RAEB-t: 80 +/- 79; CMML: 105 +/- 114 cells/mm2) compared to controls (54 +/- 51 cells/mm2). As assessed by Northern blotting and protein analysis, bm cells in MDS primarily produced alpha-(pro)tryptase, but little or no beta-tryptase. Together, our data show that elevated levels of tryptase are detectable in a group of patients with MDS probably because of an increase in neoplastic (mast) cells producing the enzyme(s). In addition, serum tryptase levels appear to correlate with MDS variants. Follow up studies should clarify whether an elevated tryptase concentration in MDS is of prognostic significance.

Adult↗
PubMed2001

Expression of mast cell tryptase by myeloblasts in a group of patients with acute myeloid leukemia.

alpha- and beta-tryptase genes encode serine proteases that are abundantly expressed by mast cells. Under physiologic conditions other myeloid cells are virtually tryptase negative. However, tryptases are also expressed in several myeloid leukemia cell lines. In this study, serum total tryptase levels were determined in 150 patients with acute leukemias (de novo acute myeloid leukemia [AML], n = 108; secondary AML, n = 25; acute lymphoid leukemia [ALL], n = 17) by fluoroenzyme immunoassay. In healthy subjects (n = 30), tryptase levels ranged between 2.0 and 12.6 ng/mL. Elevated tryptase levels (> 15) were detected in 42 (39%) of 108 patients with de novo AML and in 11 (44%) of 25 patients with secondary AML. No elevated tryptase levels were found in patients with ALL. In de novo AML, elevated tryptase levels were frequently detected in patients with French-American-British classification M0 (6 of 9), M2 (9 of 14), M3 (4 of 6), and M4eo (7 of 7), and less frequently in M1 (7 of 20), M4 (6 of 26), M5 (2 of 18), M6 (0 of 5), or M7 (1 of 3). The highest tryptase levels were found in M4eo. Immunohistochemical staining of bone marrow sections with anti-tryptase antibody as well as immunoelectron microscopy revealed tryptase expression in the cytoplasm of myeloblasts. As assessed by Northern blotting and reverse transcriptase-polymerase chain reaction, AML cells expressed alpha-tryptase messenger RNA (mRNA) but little or no beta-tryptase mRNA. In AML patients with elevated serum tryptase before chemotherapy, who entered complete remission, tryptase levels returned to normal or near normal values. Blast cell persistence or regrowth was associated with a persistently elevated level or recurrent increase of tryptase. Together, tryptase is expressed in myeloblasts in a group of AML and may serve as a useful disease-related marker.

Acute Disease↗
PubMed2001

Human skin-derived mast cells can proliferate while retaining their characteristic functional and protease phenotypes.

Human mast cells in adult tissues have been thought to have limited, if any, proliferative potential. The current study examined mast cells obtained from adult skin and cultured in serum-free medium with recombinant human stem cell factor. During the first 4 weeks of culture, the percentages of mast cells increased from 10 to almost 100. After 8 weeks, a 150-fold increase in the number of mast cells was observed. When freshly dispersed mast cells were individually sorted onto human fibroblast monolayers and cultured for 3 weeks, one or more mast cells were detected in about two thirds of the wells, and in about two thirds of these wells the surviving mast cells showed evidence of proliferation, indicating most mast cells in skin can proliferate. Such mast cells all expressed high surface levels of Kit and Fc epsilon RI, each of which were functional, indicating IgE was not required for Fc epsilon RI expression on mast cells. Such mast cells also retained the MC(TC) protease phenotype of mast cells that normally reside in the dermis. After 4 to 8 weeks of culture these mast cells degranulated in response to substance P and compound 48/80, characteristics of skin-derived mast cells that persist outside of the cutaneous microenvironment. (Blood. 2001;97:2045-2052)

Adult↗
PubMed2001

Patency and limb salvage after infrainguinal bypass with severely compromised ("blind") outflow.

HYPOTHESIS: Infrainguinal graft patency and limb salvage are adversely affected by severely compromised outflow. DESIGN: Retrospective review of all infrainguinal bypass procedures performed at a single institution during a 5-year period. SETTING: University teaching hospital. PATIENTS: Two hundred seventy-four patients underwent infrainguinal bypass for limb salvage (351 grafts in 307 limbs). INTERVENTIONS: All infrainguinal bypasses originated from a femoral artery. The distal anastomosis in 279 grafts was located in an artery with at least 1 patent outflow vessel with anatomically normal end-artery runoff (Society for Vascular Surgery/International Society for Cardiovascular Surgery ad hoc committee runoff score, 1-9). The distal anastomosis of 72 grafts was located in an artery with only collateral outflow ("blind bypass"; runoff score, 10). MAIN OUTCOME MEASURES: Perioperative morbidity and mortality, primary-assisted and secondary graft patency, limb salvage, and survival. RESULTS: All data are presented as mean +/- SEM. Patients undergoing blind bypass were older (age, 70 +/- 2 vs. 66 +/- 1 years; P <.05) and had a higher incidence of hypertension (90% vs 70%; P <.05) and end-stage renal disease (24% vs. 13%; P <.05). Comparing patients undergoing blind bypass to bypass with at least 1 patent outflow vessel, there were no differences in the use of nonautogenous conduits (50% vs 59%; P =.21) or postoperative warfarin (30% vs 32%; P =.69), or in perioperative mortality rates (2.7% vs 3.2%; P =.79). After a median follow-up of 13 months (range, 0-60 months), 2-year secondary graft patency for the entire group was 63% +/- 4%. The secondary patency rate of blind bypass grafts was no different from that of grafts with at least 1 patent outflow vessel (67% +/- 7% vs. 64% +/- 4%; P was not significant). However, the 2-year limb salvage rate in limbs with blind outflow was significantly worse than in limbs with at least 1 patent outflow vessel (67% +/- 7% vs. 76% +/- 3%; P =.04). CONCLUSION: Acceptable long-term patency rates can be achieved in infrainguinal bypass grafts with blind outflow, although blind outflow remains a marker for subsequent limb loss in the chronically ischemic leg.

Aged↗
PubMed2001

The hemodynamics of vein grafts: measurement and meaning.

The long-term patency of infrainguinal vein grafts appears to depend primarily on the size and quality of the venous conduit. Therefore, those quantities which directly relate to the conduit's ability to act as a transporter of blood, namely internal diameter and longitudinal impedance (Z(L)), have predictive value for patency. Autologous grafts of good quality frequently remain patent even with compromised outflow. Therefore, those quantities that are outflow dependent, including deltaP, flow, velocity, shear stress, and resistance, carry less predictive value for long-term performance.

Blood Flow Velocity↗
PubMed2001

Adenoviral-mediated gene transfer in human and animal vein grafts using clinically relevant exposure times, pressures, and viral concentrations.

This study examined the efficiency of adenoviral-mediated gene transfer in experimental vein grafts and cultured human saphenous vein under physiologic conditions using clinically relevant exposure times, pressures, and viral concentrations. The external jugular veins of 25 male New Zealand White rabbits were exposed to 0.5 mL of replication-deficient adenovirus vectors encoding beta-galactosidase (AdlacZ), control adenovirus (AdBg/II), or vehicle at pressures ranging from 0 to 120 mmHg for 10 min. Veins were excised and grafted into the carotid circulation. After 5 days, the vessels were reexposed, excised, and stained with X-gal chromagen for beta-galactosidase (beta-gal) activity. Gene transfer was also performed in 13 segments of human saphenous vein discarded at the time of bypass grafting. The veins were cultured for 0-21 days and assayed for beta-gal activity as above. Rabbit vein grafts exposed to high-pressure AdlacZ transfection showed significant transgene expression in 100% of grafts (39 +/- 2% positive cells/hpf) while only 60% of those transfected at low pressure expressed beta-gal (9 +/- 3% positive cells/hpf). All human veins exposed to AdlacZ expressed beta-gal to a variable degree (range 10-50% positive cells/hpf). No control grafts or veins expressed the transgene. Efficient adenoviral-mediated gene transfer in experimental vein grafts and human saphenous vein segments can be achieved using clinically feasible parameters of exposure time, pressure, and viral concentration.

Adenoviridae↗
PubMed2001

Diagnostic criteria and classification of mastocytosis: a consensus proposal.

The term 'mastocytosis' denotes a heterogeneous group of disorders characterized by abnormal growth and accumulation of mast cells (MC) in one or more organ systems. Over the last 20 years, there has been an evolution in accepted classification systems for this disease. In light of such developments and novel useful markers, it seems appropriate now to re-evaluate and update the classification of mastocytosis. Here, we propose criteria to delineate categories of mastocytosis together with an updated consensus classification system. In this proposal, the diagnosis cutaneous mastocytosis (CM) is based on typical clinical and histological skin lesions and absence of definitive signs (criteria) of systemic involvement. Most patients with CM are children and present with maculopapular cutaneous mastocytosis (=urticaria pigmentosa, UP). Other less frequent forms of CM are diffuse cutaneous mastocytosis (DCM) and mastocytoma of skin. Systemic mastocytosis (SM) is commonly seen in adults and defined by multifocal histological lesions in the bone marrow (affected almost invariably) or other extracutaneous organs (major criteria) together with cytological and biochemical signs (minor criteria) of systemic disease (SM-criteria). SM is further divided into the following categories: indolent systemic mastocytosis (ISM), SM with an associated clonal hematologic non-mast cell lineage disease (AHNMD), aggressive systemic mastocytosis (ASM), and mast cell leukemia (MCL). Patients with ISM usually have maculopapular skin lesions and a good prognosis. In the group with associated hematologic disease, the AHNMD should be classified according to FAB/WHO criteria. ASM is characterized by impaired organ-function due to infiltration of the bone marrow, liver, spleen, GI-tract, or skeletal system, by pathologic MC. MCL is a 'high-grade' leukemic disease defined by increased numbers of MC in bone marrow smears (>or=20%) and peripheral blood, absence of skin lesions, multiorgan failure, and a short survival. In typical cases, circulating MC amount to >or=10% of leukocytes (classical form of MCL). Mast cell sarcoma is a unifocal tumor that consists of atypical MC and shows a destructive growth without (primary) systemic involvement. This high-grade malignant MC disease has to be distinguished from a localized benign mastocytoma in either extracutaneous organs (=extracutaneous mastocytoma) or skin. Depending on the clinical course of mastocytosis and development of an AHNMD, patients can shift from one category of MC disease into another. In all categories, mediator-related symptoms may occur and may represent a serious clinical problem. All categories of mastocytosis should be distinctively separated from reactive MC hyperplasia, MC activation syndromes, and a more or less pronounced increase in MC in myelogenous malignancies other than mastocytosis. Criteria proposed in this article should be helpful in this regard.

Adult↗
PubMed2001

Prevention of restenosis by a herpes simplex virus mutant capable of controlled long-term expression in vascular tissue in vivo.

Neointimal hyperplasia resulting from vascular smooth muscle cell (SMC) proliferation and luminal migration is the major cause of autologous vein graft failure following vascular coronary or peripheral bypass surgery. Strategies to attenuate SMC proliferation by the delivery of oligonucleotides or genes controlling cell division rely on the use of high concentrations of vectors, and require pre-emptive disruption of the endothelial cell layer. We report a genetically engineered herpes simplex virus (HSV-1) mutant that, in an in vivo rabbit model system, infects all vascular layers without prior injury to the endothelium; expresses a reporter gene driven by a viral promoter with high efficiency for at least 4 weeks; exhibits no systemic toxicity; can be eliminated at will by administration of the antiviral drug acyclovir; and significantly reduces SMC proliferation and restenosis in vein grafts in immunocompetent hosts.

Animals↗
PubMed2001

IL-6 attenuates apoptosis, while neither IL-6 nor IL-10 affect the numbers or protease phenotype of fetal liver-derived human mast cells.

BACKGROUND: The combination of recombinant human stem cell factor (rhSCF), rh interleukin (IL)-6 and rhIL-10 was reported to be optimal for mast cell development from cord blood progenitors and to induce chymase expression in all such mast cells earlier in their development than tryptase. OBJECTIVE: The effects of rhIL-6 and rhIL-10 in various combinations on the rhSCF-dependent development of human mast cells from fetal liver progenitors were examined in serum-free media. METHODS: Dispersed fetal liver cells were cultured in serum-free AIM-V medium with rhSCF alone, or with combinations of rhIL-6 and rhIL-10. Tryptase and chymase expression, surface Kit expression, metachromasia with toluidine blue and apoptosis were measured. RESULTS: Neither rhIL-6 nor rhIL-10 nor the two interleukins together, when included from day 0 of culture, affected the number or protease phenotype of mast cells at 1 or 3 weeks. Expression of tryptase paralleled the appearance of metachromasia and surface Kit, both of which preceded chymase expression, regardless whether a rabbit polyclonal or mouse monoclonal anti-chymase antibody preparation was used. On the other hand, rhIL-6 markedly attenuated baseline levels of apoptosis in the presence of rhSCF as well as apoptosis occurring after withdrawal of rhSCF, whereas rhIL-10 had no effect. CONCLUSION: RhIL-6 protected fetal liver-derived mast cells from apoptosis, particularly after withdrawal of rhSCF, but neither rhIL-6 nor rhIL-10 nor the combination of these interleukins affected the numbers or protease phenotype of these mast cells.

Apoptosis↗
PubMed2001

Grass pollen immunotherapy inhibits seasonal increases in basophils and eosinophils in the nasal epithelium.

BACKGROUND: Symptoms of allergic rhinitis are accompanied by infiltration of the nasal mucosa with inflammatory cells, predominantly eosinophils and metachromatic cells (basophils and mast cells). Specific immunotherapy (IT) reduces mucosal eosinophilia and numbers of metachromatic cells in the epithelium. A specific marker distinguishing basophils from mast cells was recently developed. OBJECTIVES: The basophil-specific monoclonal antibody 2D7 was used to determine the influence of subcutaneous IT on numbers of nasal mucosal basophils compared with the effects of IT on neutrophils, eosinophils and mast cells. METHOD: During a randomized, placebo-controlled trial of grass pollen IT in 44 adults with severe summer hay fever, nasal biopsies were taken at baseline, out of the pollen season, and at the peak of the pollen season following 2 years treatment. Biopsies were processed for immunohistochemistry for basophils (2D7+), mast cells (AA1+), eosinophils (MBP+) and neutrophils (neutrophil elastase+). RESULTS: In placebo-treated (PL) patients there were significant seasonal increases in basophils (P < 0.01), mast cells (P < 0.05) and eosinophils (P = 0.002) in the nasal submucosa. In IT-treated patients significant increases in 2D7+ cells (P < 0.01) and eosinophils (P = 0.01) but not AA1+ cells (P = 0.9) were observed. These differences were significant between groups for eosinophils (P < 0.05). In the epithelium there were seasonal increases in AA1+ cells and eosinophils in both groups (PL: P < 0.01, IT: P < 0.05 for both). The between-group difference was significant for eosinophils (P = 0.05). Basophils were observed in the epithelium of six out of 17 in the placebo group and one out of 20 in the IT group (P = 0.03). Neutrophil numbers remained constant in both epithelium and submucosa. CONCLUSION: Successful grass pollen immunotherapy was associated with inhibition of seasonal increases in basophils and eosinophils, but not mast cells or neutrophils within the nasal epithelium. Immunotherapy may act, at least in part, by reducing seasonal recruitment of basophils and eosinophils into the epithelium.

Adult↗
PubMed2001

Human mouse mast cell protease 7-like tryptase genes are pseudogenes.

BACKGROUND: Alpha-tryptase and beta-tryptase are important clinical markers for mast cell-dependent disorders. A third family of tryptase genes on human chromosome 16 has been identified and called human mouse mast cell protease 7 (hmMCP-7)-like tryptase. OBJECTIVE: This study was designed to determine whether these tryptase genes are expressed by human mast cells. METHODS: A 2842-bp hmMCP-7-like tryptase gene was cloned and sequenced from a human placental genomic library. PCR and RT-PCR procedures, respectively, were used to determine whether this tryptase gene family was present in most genomes and whether it was expressed. RESULTS: The tryptase clone was almost identical to the hmMCP-7-like tryptase II and I genes, and therefore it was called hmMCP-7-like tryptase III. All such genes encode a Gln(-3) like alpha-tryptase. They also terminate translation after amino acid 235, whereas alpha- and beta-tryptase genes each encode a 275-amino acid protein. In this study, cell lines HMC-1, KU812, and Mono-Mac-6; mast cells derived in vitro from cord blood and fetal liver progenitors; and mast cell-enriched preparations of dispersed skin and lung cells contained hmMCP-7-like tryptases in their genomes by PCR with gene-specific primers. To identify whether such genes were transcriptionally active, RT-PCR revealed alpha- or beta-tryptase products in all mast cell preparations and cell lines and in activated skin-derived mast cells, but no hmMCP-7-like tryptase products. CONCLUSION: These results indicate hmMCP-7-like tryptase (I, II, III) genes are pseudogenes and unlikely to affect measurements of alpha- and beta-tryptases.

Animals↗