Allo-SCT in children with high-risk leukemia using unmanipulated grafts from alternative donors.

Allogeneic HSCT is a curative treatment for high-risk leukemia. In Europe, approximately 15% of children have an HLA-matched sibling, but in 65-70% HLA allele-matched (9-10/10) unrelated donors (UD) can be identified. Transplantation using an HLA partially mismatched donor, unrelated cord blood or haploidentical family donor with graft manipulation is then considered with preference on the basis of local experience and/or availability. Here we evaluate the outcomes of 87 consecutive patients with leukemia transplanted with unmanipulated graft from matched or partially mismatched UD or cord blood (CB) at our institution between January 2001 and December 2007. Within the median follow-up of 30 months, the acute GVHD grade II was diagnosed in 70.9% patients; grades III-IV only in 4.6%. The overall incidence of chronic GVHD was 43.3% (extensive in 34.9%). The probability of 3-year EFS was 59.5% and that of 3-year overall survival was 66.9%. TRM at day +100 was 4.5%, and overall it was 13.8%. Fourteen patients (16.1%) died as a consequence of post-transplant leukemia relapse. We conclude that the prognosis of patients transplanted for leukemia using unmanipulated grafts from HLA-matched or partially mismatched UD or CB is comparable and satisfactory. TRM and relapse rate are lower than in the earlier period.

Prognosis of pediatric patients transplanted for Ph+ chronic myeloid leukemia in the period from 1989 to 2006 in the Czech Republic.

Chronic myeloid leukemia (CML) is a myeloproliferative disorder caused by clonal proliferation of primitive hematopoietic stem cell. The median age at diagnosis is 55 to 60 years with less than 10% of patients younger 20 years. Incidence of CML in children in the Czech Republic is 0.106 cases/100 thousands per year. Here we report outcome of 38 pediatric patients (median age 12.5 years; range 1.8 - 17.3) with Ph-positive CML diagnosed between years 1989 to 2006. Primarily chronic phase of the disease was diagnosed in 32 (84%) patients. 32 (84.2%) patients underwent hematopoietic stem cell transplantation (HSCT) with the median age at transplantation of 14.9 years (range 6.9 - 20.5 years). Out of transplanted patients 16 (50%) obtained graft from unrelated donor, 13 (41%) from matched sibling donor, 2 from haploidentical family donor and autologous transplantation has been performed in one case. 6 patients were not transplanted, 4 of them died (median 1.2 years from diagnosis), 2 are alive 0.6 and 17.8 years from the diagnosis. Overall survival (OS) in 25 patients after HSCT at our department during the whole period is 66.7% with 15/16 being in stable continuous molecular-genetic remission (94%). During the period of time results of transplantations have been significantly improved (p=0.0071). OS after HSCT until year 1997 is 25% while from year 1998 until now is 87.5%. All centers OS of patients after HSCT is 71%. Results of HSCT in children with CML obtained from the year 1998 at our center are fully comparable with results achieved in large and experienced centers. HSCT remains the only proven and effective method for the treatment of CML. Clinical studies assessing the role of tyrosine kinase inhibitors in children instead of early HSCT should be planned carefully in order to avoid sub-optimal outcomes.

[Availability of molecular genetic diagnostic services in the Czech Republic. Is it too little, too much or sufficient?]. / Nabídka diagnostických sluzeb v oblasti molekulární genetiky v Ceské republice. Je to málo, moc, nebo akorát?

Review of diagnostic services offered by molecular genetic laboratories classified according the number of laboratories dealing with individual diagnoses is presented. Three different categories were distinguished: frequently, medium and rarely offered diagnostic service. Services that concerned trombophilic factors F2 a F5 and methylentetrahydrofolatreductase, cystic fibrosis, paternity testing, gender determination, molecular testing for hemochromatose--HFE, detection of BCR/ABL fused gene, and Y-chromosomal loci DAZ and AYF examination were most frequently offered.

[HLA-DPB1 gene analysis in haematopoietic stem cell transplantations]. / Analýza HLA-DPB1 genu u transplantací hematopoetických kmenových bunek.

BACKGROUND: The HLA-DPB1 gene is probably one of HLA class II genes affecting the haematopoietic stem cell transplantation. The aim of the study was to analyse the HLA-DPB1 gene and its match/mismatch in patients transplanted from unrelated HSC donors. The PCR-SSP method was used for the typing of the HLA system. METHODS AND RESULTS: The cohort consisted of 201 pairs of patient/unrelated HSC donor. Match in HLA-A, -B, -Cw, -DRBI and -DQBI (e.g. 10/10 match) was found in 81 pairs. The HLA-DPBI was tested in them. 18 different HLA-DPBI alleles were identified in this cohort. Complete match (e.g.12/12) was detected in 3% of the 201 analysed pairs only. CONCLUSIONS: The probability of finding 12/12 matching unrelated HSC donor is limited due to the high percentage of mismatches and inaccessibility of previous HLA-DPB1 results.

[Significance of confirmatory testing of HLA system in unrelated haematopoietic stem cell donors]. / Význam konfirmacních testu HLA systému nepríbuzných dárcu hematopoetických kmenových bunek.

BACKGROUND: Haematopoietic stem cell transplantation is a standard curative therapy for some acquired haematological diseases and inherited metabolic and immunological disorders. The HLA compatibility in five loci (HLA class I -A, -B and -C and HLA class II -DRB1 and -DQB 1) of the donor/recipient pair is a prerequisite for the success of haematopoietic stem cell transplantation which represents a process of adoption donors immunity. METHODS AND RESULTS: HLA is the most polymorphic system in the human genome and this polymorphism is exactly detected by molecular genetics methods on DNA level only. In period of 2001-2004 we performed confirmatory testing of 366 unrelated haematopoietic stem cells donors from Czech and foreign registers for 256 patients. Only 16% of the donors completely matched the patients in all HLA loci. We detected HLA mismatches in the samples of 81% patient/donor pairs but these results were consonant with previous results from registers. 3% of confirmatory samples were discrepant with previous registry data. CONCLUSIONS: Despite of increasing number of available unrelated haematopoietic stem cell donors and the quality of registry HLA typing the possibility of finding the completely match donor is still limited.

[HLA-DRB1/DQA1/DQB1 alleles and haplotypes in Czech children with celiac sprue]. / HLA-DRB1/DQA1/DQB1 alely a haplotypy ceských deti s celiakální sprue.

BACKGROUND: The celiac disease (CD) is a multifactor disease resulting from a life time abnormal immune response to gluten accompanied by autoimmune characteristics, which can in sensitive individuals evoke small bowel mucosa morphologic changes. The genetically sensitive individual to CD has not been defined yet, it is obvious, however, that this illness is closely linked to the HLA class II genes. The objective of our study was to detect associations of HLA class II alleles and haplotypes DRB1/DQA1/DQB1 in Czech CD children. METHODS AND RESULTS: A group of Czech CD children diagnosed according to ESPGHAN criteria was genotyped HLA for alleles of DRB1/DQA1/DQB1 loci. Genotyping of the HLA-DRB1/DQB1 haplotypes proved statistically significant association CD with haplotypes and alleles of this genetic system. 92.9% of patients have in their HLA phenotype allele DQA1*0501 in either cis or trans configuration with the DQB1 allele *0201/*0202. The extended HLA haplotype DRB*0301/DQA1*0501/DRB1*0201 as well as the haplotype DRB1*0701/DQA1*0201/DQB1*0202, are presented in 63.6% or in 61.0% CD patients respectively. The individual HLA class II alleles DRB*0301, *0701, DQA1*0201, *0501, DQB1*0201, *0202 and the above mentioned HLA haplotypes inclusively provide genotypic frequencies significantly different from healthy Czech individuals (P < or = 0.06 +/- 0.001). These results support the opinion that the HLA molecule expressed on the cellular surface as a alpha beta heterodimer encoded by the DQA1*0501 and DQB1*0201/02 alleles in either cis or trans configuration is responsible for the primary sensitivity to this disease. We were, however, not able to find an association of various clinical forms of the CD with a certain HLA haplotype in the followed group. CONCLUSION: The CD patients have in comparison with healthy population significantly different frequency of HLA class II haplotypes. Though the finding of these alleles is not sufficient for an explicit confirmation of this diagnosis, the proof of this risky haplotype/s may notably contribute to it, namely in case of potential or latent forms of this disease.

Cytotoxic T lymphocyte precursor frequency analysis in the selection of HLA matched unrelated donors for hematopoietic stem cell transplantation: the correlation of CTLp frequency with HLA class I genotyping and aGVHD development.

The selection of human leukocyte antigen (HLA) compatible unrelated donors for hematopoietic stem cell transplantation (HSCT) is based on the direct genotyping of HLA class I and class II alleles (HLA-A, -B, -C, -DRB1, -DQB1 loci). The cellular test estimating the frequency of cytotoxic T lymphocyte precursors (CTLp) has been included into the selection procedure of unrelated donors to detect the class I alloreactivity and to predict acute graft versus host disease (aGVHD) occurrence and severity. The relationship between HLA-A, -B, -C high/medium resolution genotyping and CTLp activation was analysed in the cohort of 78 unrelated donor/patient pairs indicated for HSCT. The high frequency of CTLp (> 1:100,000) correlated significantly (p < or = 0.0002) with the incompatibilities in alleles of HLA-A, -B, -C loci. Nevertheless, the results of HLA-A, -B, -C genotyping and CTLp assay are not fully alternative, suggesting that the CTLp test gives its specific information. The high CTLp frequency (CTLpf) in 14/35 pairs fully matched by HLA class-I alleles genotyping could reflect the influence of another factors upon the CTLp activation. On the contrary, the low CTLp frequency values (< or = 1:100,000) found in 8/43 pairs with existing HLA class-I alleles incompatibilities could indicate the immunological permissivity of these particular mismatches. The clinical relevance of the CTLp test for aGVHD prediction has been also analysed. The relationship between CTLp activation in vitro and the incidence and severity of aGVHD was evaluated in 37 patients who underwent allogeneic HSCT. The severe form of aGVHD (grade III-IV) developed in 9 of 18 cases (50%) with the high pretransplant CTLpf value. The patients with the low CTLpf (n = 19) suffered from the severe form of aGVHD in 2 cases (10%) only, the remaining 17 patients from this group were without aGVHD symptoms or developed only the mild form of aGVHD (I-II). The relationship between CTLp results and the incidence and severity of aGVHD was found statistically significant (p < or = 0.01).

The relationship between HA-1 compatibility and the activation of helper T lymphocyte precursors.

The relationship between the compatibility in minor histocompatibility HA-1 antigen and the activation of helper (IL-2 producing) T lymphocyte precursors in vitro was studied in the group of 17 HLA-A2 positive HLA identical siblings. Although the number of pairs studied is still small, no correlation has been found between HA-1 compatibility and helper T lymphocyte precursors activation. The results presented here could suggest the possibility that the HTLp assay does not have to be a relevant parameter for the detection of HA-1 mismatches in HLA identical siblings.