Biomedical subjects

H Behrendt

Publications and source records attributed to H Behrendt.

At least 19 recordsLinked to original sources

PubMed2000

Traffic-related air pollution is associated with atopy in children living in urban areas.

Traffic emissions are a major source of air pollution in Western industrialized countries. To investigate the association between traffic-related air pollution and parameters of atopy, we studied 317 children 9 years of age living near major roads in two urban areas and one suburban area of a city in West Germany. Atopic sensitization was analyzed by skin-prick testing and determination of allergen-specific serum immunoglobulin E. Parents recorded allergic symptoms in a symptom diary, and physicians assessed allergic diseases. Personal NO2 exposure and NO2 concentrations in front of each child's home were measured. Outdoor NO2 was a good predictor for traffic exposure but a poor predictor for NO2 exposure at the personal level. Atopy was found to be related to outdoor NO2 (odds ratio for the association between symptoms of allergic rhinitis and outdoor NO2 = 1.81; 95% confidence interval = 1.02-3.21) but not to personal NO2 (odds ratio for the association between symptoms of allergic rhinitis and personal NO2 = 0.99; 95% confidence interval = 0.55-1.79). When the analysis was restricted to urban areas, we found that hay fever, symptoms of allergic rhinitis, wheezing, sensitization against pollen, house dust mites or cats, and milk or eggs were associated with outdoor NO2. The results indicate that traffic-related air pollution leads to increased prevalence of atopic sensitizations, allergic symptoms, and diseases.

Child↗

PubMed1999

Airway diseases and allergies in East and West German children during the first 5 years after reunification: time trends and the impact of sulphur dioxide and total suspended particles.

BACKGROUND: East-West comparison studies in Europe find higher prevalences of infectious airway diseases and lower prevalences of allergies in eastern areas. Pollution from sulphur dioxide (SO2) or total suspended particles (TSP) are discussed as causes of this difference. METHODS: In four differently polluted areas of East Germany where pollution decreased dramatically between 1989 and 1995 cross-sectional studies in about 7-year-old children were repeated every year between 1991 and 1995. In two differently polluted areas of West Germany studies with the same design were done in 1991 and 1994. In all, 19090 children participated in the study. Thirteen different questions about airway diseases and allergies were evaluated. Logistic regression was used to adjust for confounding. RESULTS: With the exception of pneumonia, all infectious airway diseases and irritations of the airways show a steeper temporal decrease in East than in West Germany or are positively associated with either SO2 or TSP in East Germany. For allergies and related symptoms no differences in time trends could be detected or no association with SO2 or TSP could be seen in East Germany. CONCLUSION: Most airway diseases were more frequent in East than in West Germany in 1991 and were associated with SO2 or TSP. The decrease in these pollutants between 1991 and 1995 has already had a favourable effect. An effect of SO2 or TSP pollution on allergies and related symptoms could not be detected. This pollution does not protect against the development of allergies.

Age Distribution↗

PubMed1999

"Eco-syndrome" ("multiple chemical sensitivity"--MCS).

In the physicians's practice in past decades, an increasing number of patients suffering from polysomatic complaints with a subjective feeling of allergy against environmental noxious agents have been seen. Various names for this condition include "Eco-Syndrome" or "Multiple Chemical Sensitivity" (MCS), "Multiorgan Dysesthesia" or "Idiopathic Environmental Intolerances". The uncertainty in the nomenclature reflects the deficiency in the knowledge of the etiopathophysiology and accordingly the diagnostic and therapeutic procedures. Most patients have completed an odyssey of visiting various specialists including psychiatrists and undergone many kinds of so-called alternative or parascientific procedures. We studied such patients since the early 1980s performing intensive interdisciplinary and allergological investigations. In about two third of the patients psychiatric or psychosomatic disturbances were obvious, but in one third of the patients somatic pathophysiological conditions were regarded as predominant cause of the present complaints. Many patients exhibited various pathophysiological patterns including somatic and psychosomatic alterations. Measurements of indoor air pollutants in the dust or in the air showed in some cases increased values of aromatic hydrocarbones, terpenes etc., without, however, explaining the main complaints. We conclude from our experience that patients presenting with hypersensitivity phenomena related to indoor air pollution are a heterogeneous group. There is no evidence, that "MCS" really exists, often it is diagnosed by the patients themselves. The term "eco-syndrome" describes a "working diagnosis" in order to apply careful interdisciplinary investigations for this heterogeneous group of patients. For the practical management of these patients mutual confidence is a prerequisite for success. The role of indoor air pollutants in triggering unspecific complaints beyond the exclusively toxicological field remains to be elucidated by future studies.

Diagnosis, Differential↗

PubMed1998

[Late sequelae of oncologic treatment in children].

The risk of late effects of cancer treatment in children is higher than that after treatment during adulthood. The late effects of chemotherapy are proportional to the dosage and those of irradiation to the size of the radiation field, fractionation and dose. Irradiation may lead to impaired growth of bone and soft tissues, cranial irradiation to pituitary deficiencies, alopecia and impaired cognitive function, irradiation of the neck to altered thyroid function, thoracic irradiation to diminished pulmonary function and cardiovascular morbidity, radiation therapy of the abdomen to infertility in females, impaired renal function and chronic enteritis. Chemotherapy-induced damage is more organ-specific. Well-known cardiotoxic agents are the anthracycline derivatives. Restricted pulmonary function is seen after treatment with bleomycin and nitrourea derivatives. Several antineoplastic agents are gonadotoxic in men. Nephrotoxic agents are cisplatin and ifosfamide. The cumulative relative risk of developing a second primary neoplasm is 3,8-6,9 after a follow-up period of 25 years. Alkylating agents and the topoisomerase inhibitors are known to increase the risk of haematologic malignancy, while radiation therapy is associated with bone, soft tissue, thyroid, breast, brain and gastrointestinal malignancies.

Adolescent↗

PubMed1998

Mutational analysis of Bax and Bcl-2 in childhood acute lymphoblastic leukaemia.

In childhood acute lymphoblastic leukaemia there are large interpatient variations in levels of the apoptosis-regulating proteins Bax and Bcl-2, but the molecular basis for this variation is unknown. Point-mutations in bax have been reported in cell lines derived from haematological malignancies. Frameshift mutations, which result in reduced Bax levels, have also been found in colon cancer of the microsatellite mutator phenotype. Bcl-2 overexpression, or gain of function mutations in the open reading frame (ORF) or in the translational repressor, the upstream ORF(uORF) of bcl-2, might also be important in deregulating its function or expression. We have therefore analyzed 21 bone marrow aspirates from untreated childhood acute lymphoblastic leukaemia and 2 from myeloid leukaemia for mutations in box and bcl-2. DNA sequence analysis of the ORFs of bax and bcl-2 and of the uORF of bcl-2 revealed no mutations, despite the large range in expression levels. Thus, mutations within the (u)ORFs of bax and bcl-2 that (in)activate or deregulate Bax and Bcl-2 are infrequent in primary childhood acute leukaemia and do not play a major role in regulation of the encoded proteins in this disease.

Adolescent↗

PubMed1998

Favorable outcome after 1-year treatment of childhood T-cell lymphoma/T-cell acute lymphoblastic leukemia.

BACKGROUND: For T-malignancies in children a poor prognosis is reported. In these malignancies a combination of lymphoma and leukemia is commonly seen at presentation and most patients are treated according to protocols for acute lymphoblastic leukemia (ALL). These protocols are often designed for the majority of ALL cases, i.e., progenitor-B-ALL. In pediatric lymphoblastic non-Hodgkin's lymphoma without bone marrow infiltration various protocols have been used. The most frequently reported regimens show variable survival rates between 40 and 75%. PATIENTS AND METHODS: From 1989 we have treated 32 consecutive patients with T-cell malignancies, irrespective of localization, with a protocol consisting of a 4-agent induction treatment followed by high doses of methotrexate, and cytosine-arabinoside and intensified bleomycin, adriamycin, cyclophosphamide, vin cristin, prednisone (BACOP) courses. Treatment duration for each patient was 1 year. Twenty-one of the 32 patients had stage IV disease. Follow-up ranged from 1.6 to 7.6 years (median 4.2 years). RESULTS: Overall event-free survival (EFS) was 72%, while in those with stage IV disease it was 67%. No therapy-related deaths occurred. Neither stage, initial leukocyte value, mediastinal involvement, bone marrow involvement, nor the presence of CD1, CD3, CD4, CD8, or CD10 epitopes was prognostically significant. Evaluation of toxicity revealed a minimal decrease of carbon monoxide diffusion and cardiac shortening fraction. CONCLUSION: A relatively short but intensive chemotherapy can be used in T-cell malignancies. The EFS is satisfying, but larger studies are needed.

Adolescent↗

PubMed1998

Long-term neuro-endocrine sequelae after treatment for childhood medulloblastoma.

The occurrence of neuro-endocrine deficiencies following craniospinal irradiation for medulloblastoma is well known, but data concerning the spectrum and prevalence of endocrine abnormalities in adulthood are scarce. We studied endocrine function in 20 (median age 25 years) adult subjects, 8-25 years (median 16 years) after therapy. The radiation dose to the whole cranium and spinal axis was 35 +/- 2.6 Gray (mean +/- standard deviation) with a boost to the posterior fossa of 18 +/- 3.7 Gray. 13 subjects had received additional chemotherapy. In 15 of 20 (75%) subjects, endocrine abnormalities were observed. In 14 (70%), growth hormone (GH) secretion was impaired; 7 (35%) subjects had an absolute GH deficiency, while 7 (35%) showed subnormal responses to insulin-induced hypoglycaemia. In contrast, only 20% (4) of these subjects showed impairment of the hypothalamus-pituitary-thyroid (HPT) axis, while 15% (3) showed central impairment of hypothalamus-pituitary-gonadal (HPG) function. Central impairment of the HPG axis was associated with impaired GH secretion in all cases. Central adrenal insufficiency was not observed. Basal levels of prolactin were normal in all subjects. Young age at treatment was a determinant of GH deficiency in adulthood (P = 0.014). Neither post-treatment interval, nor the use of chemotherapy were determinants of central endocrine impairment in adulthood. In long-term survivors of medulloblastoma, GH deficiency has a high prevalence. In contrast, impairment of the HPG and HPT axis is less common, while central adrenal insufficiency was not observed.

Adolescent↗

PubMed1998

Trichothiodystrophy without associated neuroectodermal defects.

Trichothiodystrophy leading to generalized trichorrhexis nodosa-like hair changes with abnormal hair breakage is described in a 4-year-old girl. A marked deficiency of sulphur and the sulphur-containing amino acid, cystine, was detected in the biochemical analysis of the hair. Further investigation of the hair showed the morphological criteria of trichothiodystrophy. Commonly related symptoms, such as mental retardation, ichthyosis and increased sensitivity to sunlight, were not present in our patient.

Child, Preschool↗

PubMed1998

The influence of cultural and educational factors on the validity of symptom and diagnosis questions for atopic eczema.

Valid questions for atopic eczema are necessary to identify risk factors in epidemiological studies. We have examined the influence of cultural and educational factors on the validity of some questions on atopic eczema used in the International Study of Asthma and Allergies in Childhood by using data from a cross-sectional study on 1511 children aged 6 years from East and West Germany. We tested three questions in relation to a point prevalence of atopic eczema as recorded by a dermatologist: (i) has a physician ever diagnosed eczema in your child? (ii) Has your child ever had an itchy rash which came and went for at least 6 months? (iii) Has your child ever had 'neurodermatitis' (atopic eczema, endogenous eczema)? The point prevalence of atopic eczema on the day of investigation was 11.1% (134 of 1217). According to the questionnaire, 15.7% of the children had had physician-diagnosed eczema, 14.1% had had neurodermatitis and 11.3% had had an itchy rash for > 6 months. Fifty-one per cent of parents who had a child with atopic eczema on the day of investigation said that their child had had an itchy rash which came and went for at least 6 months. This sensitivity value is less than that found in another community survey conducted in the U.K., suggesting that the German wording of the question seems to mean something more severe to the parents than the English one. The education of the parents had an influence on the validity of the three questions: parents with < 10 years of schooling often answered symptom and diagnosis questions less positively. Parents with academic degrees, contrary to expectation, did not answer most precisely, this being especially true for the symptom questions. The association between symptom questions and clinical diagnosis was higher in West than in East Germany. We compared lifetime eczema symptoms and diagnosis with a point prevalence clinical diagnosis. In the absence of knowledge of how extraneous factors measured in this paper can affect diseases chronicity, it is difficult to say with certainty that such factors affect the validity of symptom and diagnosis questions on atopic eczema. Our study suggests that more studies are needed to examine the influence of social class, education and location on the validity of symptom questionnaires for atopic eczema. Until then, we recommend that information about such variables should be gathered routinely.

Child↗

PubMed1998

Determination of histamine and leukotrienes from basophils in cell supernatants by high-performance liquid chromatography.

A reversed-phase high-performance liquid chromatographic method with gradient elution for the separation of the mediator substances histamine and the leukotrienes C4 (LTC4), D4 (LTD4), and E4 (LTE4) is described. The detection occurs fluorimetrically after automated precolumn derivatization with o-phthaldialdehyde. All components are chromatographically separable. Because of the different excitation and emission wavelengths, only the most important biological active mediators histamine and LTC4 are determinable in one parallel chromatographic run. The method is examined by linearity and precision tests and is applicable to biological sample matrices like cell supernatants of human basophils enriched by Percoll-density gradient centrifugation and stimulated for mediator release by anti-IgE. The established method is suitable to separate the mediators from other matrix components. The determination limit for histamine is 55.0 micrograms/L and that for LTC4 16.0 micrograms/L, referring to the reference solutions. Therefore, a fast, economical method for the common determination of the most important mediators histamine and LTC4 is established. This method is also suitable for high sample amounts in routine medical analysis.

Basophils↗

PubMed1997

Airborne particulate matter modulates the production of reactive oxygen species in human polymorphonuclear granulocytes.

Causal relationships between airborne particles (especially particulate matter < 10 microm in diameter) and increases in prevalences and symptoms of respiratory diseases have been postulated in many epidemiologic studies. Polymorphonuclear leukocytes (PMN) in the nasal or bronchial epithelium can be exposed to particulate matter (PM) and may upon exposure produce reactive oxygen species (ROS). Release of ROS can result in cellular and tissue damage and initiate or exacerbate inflammation. To elucidate the effect of PM on inflammatory reactions, we exposed human PMN to PM extracts. PM were collected with high volume samplers in two cities, Dusseldorf and Duisburg, in Germany and reflect sites with high traffic and industrial emissions respectively. The collected particles were extracted using water and then dichloromethane, resulting in an aqueous and an organic extract. The production of ROS was determined using luminol-enhanced chemiluminescence (LCL) of resting and zymosan-stimulated PMN. The present study shows that extracts of PM alone significantly stimulated the production and release of ROS in resting PMN. The effects of the PM extracts were inhibited by superoxide dismutase (SOD), catalase and sodium azide (NaN3). Zymosan-induced LCL was, however, diminished by coincubation with PM extracts. The chemical composition is important when considering the effects of particles. Our study shows that only organic substances adsorbed to particles stimulate LCL. SOZ-induced LCL is inhibited by both types of extracts, but aqueous extracts have a stronger inhibitory effect. It is at present unclear which substances are responsible for these effects.

Air Pollutants↗

PubMed1997

The Bax alpha:Bcl-2 ratio modulates the response to dexamethasone in leukaemic cells and is highly variable in childhood acute leukaemia.

Bcl-2 over-expression has been shown to inhibit apoptosis induced by a variety of stimuli, whereas a predominance of Bax alpha to Bcl-2 accelerates apoptosis upon apoptotic stimuli. We sought to study the relevance of these apoptotic regulating gene products in leukaemia. In a panel of leukaemia and lymphoma cell lines (HL60, DoHH2, CEM C7, L1210 and S49), the Bax alpha-to-Bcl-2 ratio as assessed by Western-blot analysis correlated with sensitivity to dexamethasone treatment. In addition, in HAbax alpha-transfected CEM C7 clones, a similar correlation was found for dexamethasone and thapsigargin sensitivity. In bone-marrow aspirates from patients with childhood acute lymphoblastic or myelocytic leukaemia (ALL, n = 48; AML, n = 8), the Bcl-2 and Bax alpha levels were highly variable, but well within the range found in the Bax alpha transfectants and in the established cell lines. Bcl-2 levels were lower in T- than in B-lineage ALL, which could be ascribed to simultaneous inverse relation between Bcl-2 and WBC. By contrast, Bax alpha:Bcl-2 was independent of any presenting feature and was largely dependent on Bax alpha levels. Results suggest that Bax alpha:Bcl-2, rather than Bcl-2 alone is important for the survival of drug-induced apoptosis in leukemic cell lines and ALL.

Apoptosis↗

PubMed1997

Treatment of isolated testicular recurrence of acute lymphoblastic leukemia without radiotherapy. Report from the Dutch Late Effects Study Group.

BACKGROUND: The isolated recurrence of testicular leukemia in boys with acute lymphoblastic leukemia (ALL) is considered to be an ominous sign, heralding generalized recurrence. In general, treatment is comprised of systemic retreatment and local radiotherapy to one or both affected tests. METHODS: In this study, the authors report five boys with a late isolated testicular recurrence of ALL during sustained bone marrow remission, in whom radiotherapy had been omitted. High dose methotrexate was included in the treatment regimen. RESULTS: No further recurrences occurred after cessation of therapy. The follow-up period ranged from 1-15 years (median, 8 years). CONCLUSIONS: These cases show that there is a subpopulation of boys with recurrence of testicular leukemia who can be treated without radiotherapy. Therefore, the authors propose a treatment regimen for boys with late isolated recurrence of testicular leukemia in which conventional reinduction maintenance treatment is given in combination with high dose methotrexate. Radiotherapy should be withheld until subsequent testicular recurrence occurs.

Antimetabolites, Antineoplastic↗

PubMed1997

Treatment of Hodgkin's disease in children with alternating mechlorethamine, vincristine, procarbazine, and prednisone (MOPP) and adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD) courses without radiotherapy.

Since the introduction of mechlorethamine, vincristine, procarbazine, and prednisone (MOPP) chemotherapy, children with Hodgkin's disease (HD) have been treated with chemotherapy alone. The occurrence of side effects related to irradiation (especially secondary solid tumors) is less likely to occur. Alkylating agents in the MOPP chemotherapy combinations are, however, known for their late effects, i.e., gonadal dysfunction and secondary malignancies. Combination with non-alkylating and non-cross-resistant drugs (as in the adriamycin, bleomycin, vinblastine, and dacarbazine [ABVD] combination: may give superior treatment results and possibly a decrease in the occurrence of side effects. From 1988 to 1993 all children presenting with HD were treated with alternating MOPP and ABVD courses (3 x MOPP, 3 x ABVD). Twenty-one children (7 females, 14 males), ages 5-18 years (median 14 years) were included; their clinical stages were 1, 7 patients; II, 8 patients; III, 5 patients; IV, 1 patient. Their pathology revealed 2 lymphocytic predominance, 17 nodular sclerosis, 1 mixed cellularity. In 1 patient only cytology was done and thus histopathologic subclassification was not possible. Two children have relapsed; disease-free survival is 90%. Analysis of toxicity revealed no decrease in cardiac function by ultrasound examination and no pulmonary effects noted by carbon monoxide diffusion. In 1 of the 10 children tested, mild hypogonadism was noted. No secondary tumors occurred. From this small population of children with HD we conclude that treatment with MOPP/ABVD for 6 cycles without radiotherapy may be adequate. The occurrence of gonadal dysfunction may be less frequent than with 6 cycles of MOPP. However, more patients and further follow-up are needed.

Adolescent↗

PubMed1997

Characterization of Ambient Air Particle Size Fractions in Three GermanCities with the Aid of Electron Microscopy

Multistage-filtration samplers offer the opportunity toanalyze dust fractions deposited on corresponding stages of the sampler. Inthis investigation, a typical two-stage sampler was used in the cities ofDortmund (mining and steel industry), Dusseldorf (lesser industrialactivities), and Duisburg (steel industry), North Rhine Westphalia. Thepurpose of this study was to compare the composition of dust fractions withthe aid of analytical electron transmission microscopical methods. Theparticle size distribution was similar in the cities, the 50% value ofthe equivalent diameter was 0.8 μm. Analytical results are presented fordifferent mineral classes with approximately 30 single minerals in allcities. The highest concentration values in the fine dust fraction weresilicate minerals, while the sulfate content was very high in the coarse dustfraction in all cities.

Journal Article↗

PubMed1997

Rearrangement status of the malignant cell determines type of secondary IgH rearrangement (V-replacement or V to DJ joining) in childhood B precursor acute lymphoblastic leukemia.

Immunoglobulin heavy chain (IgH) oligoclonality in childhood B precursor acute lymphoblastic leukemia (ALL) as determined by Southern analysis is found in 30-50% of patients and has been shown to be the result of ongoing IgH rearrangement (mostly V(H)-replacement and V(H) to D-J(H) joining) after malignant transformation. It is unknown however, what determines the type of secondary rearrangement. Also the biological basis of the variable degree of oligoclonality observed in childhood ALL is poorly understood. We analyzed in detail the IgH rearrangement status of the leukemic cells for a random panel of 18 childhood B precursor ALL patients by polymerase chain reaction (PCR)/sequencing analysis and by Southern analysis. By Southern analysis 10/18 (55.6%) patients were considered oligoclonal and 8/18 (44.4%) monoclonal. In contrast, by PCR minor clonal rearrangements were detected in 14/18 (77.8%) patients. V(H)-replacement was found in 7/14 patients, V(H) to D-J(H) joining in 6/14 patients and an unusual type of secondary rearrangement, V(H)-D to J(H) joining, in one patient. Only a single type of secondary rearrangement was detected in each patient. The type of secondary rearrangement (V(H)-replacement or V(H) to D-J(H) joining) depended on the rearrangement status (VDJ/VDJ or VDJ/DJ, respectively) of the dominant leukemic clone as determined by Southern analysis. We found that in addition to a more 'advanced' IgH rearrangement status patients with V(H)-replacements also have a more 'advanced' TCRdelta rearrangement status, which possibly reflects exposure of both the IgH locus and the TCRdelta locus to recombinase activity in a preleukemic clone. Finally, we investigated a putative relationship between oligoclonality by Southern analysis and S-phase fraction of the leukemic cell population. We found a significantly lower percentage cells in S-phase for oligoclonal patients as compared to monoclonal patients. Our data add to the understanding of ongoing rearrangement of antigen receptor loci in childhood ALL and have implications for the monitoring of minimal residual disease by PCR.

Adolescent↗

PubMed1997

Gramineae pollen as trigger factors of atopic eczema: evaluation of diagnostic measures using the atopy patch test.

After contact with grass pollen, seasonal exacerbations of eczematous skin lesions have been described in a subgroup of patients with atopic eczema (AE). Epicutaneous patch testing with aeroallergens (atopy patch test. APT) has been used to investigate these patients. We performed comparative APT in 79 patients with AE and 20 control subjects (14 non-atopic volunteers and six patients with grass pollen allergic rhinoconjunctivitis). Subjects were tested with grass pollen allergen extract in petrolatum and with unprocessed native dry pollen of Dactylis glomerata. Results after 48 h were compared with the patient's history, corresponding skin prick test and specific IgE. Fifteen of the 79 AE patients showed clear-cut eczematous reactions to unprocessed D. glomerata pollen; 14 of these had an elevated serum IgE to D. glomerata and 13 had a positive skin prick test. Twenty patients had a positive APT reaction to grass pollen allergen extract, including 12 of the D. glomerata reactive subjects (P < 0.001). Positive patch test reactions to D. glomerata were seen in 66.7% of cases with and 10.5% of patients without a predictive history of exacerbations during the pollen season. For the standardized extract, these percentages were 75% vs. 16.4% (P < 0.001). No side-effects were observed. Control subjects showed no positive reactions. We conclude that grass pollen preparations may be used to investigate trigger factors for eczematous skin lesions in a subgroup of patients with AE.

Adolescent↗

PubMed1997

PCR-positivity in harvested bone marrow predicts relapse after transplantation with autologous purged bone marrow in children in second remission of precursor B-cell acute leukaemia.

Purging of autologous bone marrow (BM) grafts of children in second remission after a relapse of precursor B acute lymphoblastic leukaemia (ALL) in the BM has been carried out in our laboratory since 1987, initially by complement mediated cell lysis. This protocol was extended by performing an immunorosette depletion before lysis with complement. The aim of the present study was to assess by polymerase chain reaction the presence of residual leukaemic cells in the BM grafts before and after purging. The results were then correlated to clinical outcome. In 24/28 patients a PCR product was obtained by amplification of IgH and/or TcR junctional regions. BM before purging was available for analysis in 13 patients. We found that leukaemic cells could be detected in 8/13 (62%) of these grafts before purging . All these eight patients experienced a relapse, regardless of whether the purging procedure had been successful (defined as achievement of PCR-negativity) or not. In contrast, none of the five patients with PCR-negative grafts before purging relapsed (P = 0.0008). One patient died due to transplant-related toxicity. Of the remaining 23 patients, nine patients received a PCR-positive BM graft after purging. All these nine patients experienced a relapse as compared to 6/14 whose BM was PCR-negative after purging (P = 0.0072). Two of eight PCR-positive BM grafts could be purged to PCR-negativity. Thus, improvements both in treatment of leukaemia and in purging efficacy are still needed.

Adolescent↗