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Patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) always require platelet transfusions, but the increase in platelet count is often less than expected. Since factors responsible for poor response to platelet transfusions in this clinical setting are largely unknown, we performed a prospective study in 87 consecutive children transplanted in a single institution. The mean 16-h corrected count increment (CCI) of 598 platelet transfusions was 5.76 +/- 8.32 x 10(9)/l. Both before and after HSCT, 13.8% of patients had antibodies against HLA and/or platelet-specific antigens. Univariate analysis identified 12 factors significantly associated with a lower post-transfusion CCI, but only four reached statistical significance in the multivariate analysis. These four factors were concomitant therapy with vancomycin, alloimmunization, use of an Autopheresis cell separator for preparation of platelet concentrates and cytomegalovirus infection. We, therefore, suggest that a better response to platelet transfusions could be obtained by choosing a suitable cell separator, by avoiding the use of vancomycin and by adopting measures that reduce alloimmunization and CMV infection. Moreover, screening patients for HLA and platelet-specific antibodies before HSCT would identify the majority of subjects who will develop alloimmune refractoriness after transplantation and would allow the search for a compatible donor in advance. [ABSTRACT FROM AUTHOR]

Background: Extracorporeal photochemotherapy (EPC) has recently been proposed for the treatment of adults with either acute or chronic GVHD. However, data on children given this therapy are scarce. A Phase I-II study was carried out on EPC in children experiencing GVHD after allogeneic transplantation of HPCs.Study Design and Methods: Nine patients with steroid-resistant, grade II-IV acute GVHD and 14 with chronic GVHD, all of whom had been refractory to at least one line of treatment, were enrolled in this study and analyzed. The median age was 10.3 years (range, 5.4-18.1), and the median body weight was 35 kg (range, 17-89).Results: Seven of the nine patients with acute GVHD showed a response to EPC, whereas the disease progressed in the remaining two children (both with skin, gastrointestinal, and liver GVHD), and they died of grade IV acute GVHD. Among the seven children who responded to EPC, it was possible to completely discontinue immunosuppressive treatment in three. In the 14 children with chronic GVHD, 4 and 5 patients experienced complete and partial response to EPC, respectively, whereas the remaining 5 patients, all with extensive chronic GVHD, had stable disease or disease that progressed during EPC. Among these latter 5 patients, 3 died. In 6 of the 9 patients with chronic GVHD responding to EPC, immunosuppressive therapy was discontinued.Conclusion: EPC is safe, feasible, and effective in children with either acute or chronic GVHD occurring after an allograft. [ABSTRACT FROM AUTHOR]

We compared the immunogenetic data from 2666 patients affected by HLA-related autoimmune diseases with those from 4389 ethnically matched controls (3157 cord blood donors CBD, 1232 adult bone marrow donors BMD), to verify the appropriateness of HLA typing requests received in the past decade. The frequency of HLA-B* 27 phenotype was 10.50% in 724 ankylosing spondylitis, 16.80% in 125 uveitis (3.41% BMD, 4.24% CBD, P < 0.0001); HLA-B*51 allele was 15.57% in 212 Behçet's disease (12.91% BMD, 9.88% CBD, P < 0.0001); the HLA-DRB1-rheumatoid arthritis (RA) shared epitope was 13.72% in 554 RA (10.85% BMD, 13.48% CBD, P = 0.016); the carriers of almost one of HLA-DQB1 susceptibility alleles were 84.91% in 795 celiac disease (CD) and 59.37% in 256 insulin-dependent diabetes mellitus (IDDM) (46.06% in 875 CBD, 42.75% in 662 BMD P < 0.0001). Overall, our results show that the HLA marker frequencies were higher in patients than controls, but lower than expected from the literature data (excluding CD and IDDM) and demonstrate that, in complex immunogenetic conditions, a substantial number of genetic analyses are redundant and inappropriate, burdening to the public health costs. For this reason, we suggest the Italian Scientific Society of Immunogenetics to establish guidelines to improve the appropriateness of typing requests. [ABSTRACT FROM AUTHOR]

Whipple's disease (WD) is a very rare chronic systemic condition characterised by a Th2/T regulatory (Treg) dysregulated immune response versus Tropheryma whipplei, a bacterium widely diffuse in the environment. To investigate whether this Th2/Treg polarised response has a genetic background, we investigated the Th1, Th2, Th17 and Treg cytokine genetic profile of 133 patients with WD. Thanks to the European Consortium on WD (QLG1-CT-2002-01049), the polymorphism of 13 cytokine genes was analysed in 111 German and 22 Italian patients using the polymerase chain reaction with sequence-specific primers (PCR-SSP) technique. The frequencies of the genotypes, haplotypes and functional phenotypes were compared with those obtained in 201 German and 140 Italian controls. Clinical heterogeneity was also considered. Functionally, WD patients may be considered as low producers of TGF-β1, having an increased frequency of the genotype TGF-β1+869C/C,+915C/C [12.3 % vs. 3.81 %, odds ratio (OR) = 4.131, p = 0.0002] and high secretors of IL-4, carrying the genotype IL-4-590T/T (5.34 % vs. 1.17 %, OR = 5.09, p = 0.0096). No significant association was found between cytokine polymorphism and clinical variability. Analogously to the recent cellular findings of a Th2/Treg polarised response, we showed that the cytokine genetic profile of WD patients is skewed toward a Th2 and Treg response. This was similar in both German and Italian populations. However, the significant deviations versus the controls are poorer than that expected on the basis of these recent cellular findings. [ABSTRACT FROM AUTHOR]

The HLA genomic structure underlines the permanence of fixed haplotypes transmitted in blocks as allelic combinations. One of the most discussed concerns is how and why such a strong linkage between HLA alleles has been maintained for so long. We hypothesized a possible KIR-driven pressure in the genesis of specific HLA-A,B haplotypes. Certain HLA-A and -B molecules are ligands for the same KIR receptors through the Bw4 binding motif spanning residues 77-83 in the α1 domain. We analyzed the HLA-A and -B genomic types of 9897 Caucasian people (3533 newborns and 6364 adults) subdividing them according to the presence/absence of the HLA-B Bw4 serological epitope. For each HLA-B Bw4- and Bw6-cross-reactive group, we evaluated the presence/absence of HLA-A ligands for KIR3DL1 (HLA-A*23, HLA-A*24, HLA-A*32) and KIR3DL2 (HLA-A*03, HLA-A*11). The frequency of HLA-A KIR ligands significantly increased moving from the HLA-B Bw4/Bw4 to the HLA-B Bw4/Bw6 and the HLA-B Bw6/Bw6 groups among both newborns and adults (P<0.0001). Here, we suggest that, when the HLA-B KIR-ligand motif is lacking, the HLA-A KIR-ligand might have a vicarious role in controlling the natural killer cell-mediated innate immune response. Basing upon this compensatory function in the engagement of KIR receptors, we hypothesize that specific HLA-A,B ancestral haplotypes were generated. [ABSTRACT FROM AUTHOR]

Abstract: Background: Increasing the safety in Immunogenetics Labs, in the era of antiretroviral pharmacogenomics, represents an imperative goal. To this purpose, we tested saliva and buccal cells as biological sources of DNA, alternative to peripheral blood, for HLA-B*57:01 genomic typing of HIV positive patients eligible to treatment with abacavir. Methods: Blood, saliva and buccal cells of 20 voluntary donors and 20 HIV positive patients were collected. DNA was extracted with a manual commercial kit and an automated platform. Quality and quantity of DNA was evaluated with different procedures. The suitability and reliability of DNAs for HLA-B*57:01 genotyping was checked at low and high resolution level, using PCR-SSP (sequence specific primers PCR), revPCR-SSO (reverse sequence specific oligonucleotides PCR), bead array and SBT (sequence based typing) techniques. Results: DNA concentrations were qualitatively very good and quantitatively comparable in all the specimens tested with an inferior yield for cotton swabs. Comparing the results of HLA typing with different methodologies, the 100% of reproducibility was achieved. Conclusions: The viral load of buccal epithelial cells or saliva is extremely low. Here we demonstrated that the DNA from these alternative sources is appropriate for HLA-B*57:01 typing. We strongly recommend the use of this procedure to increase the safety in the lab when dealing with infectious samples. [Copyright &y& Elsevier]

Birth weight is known to be a direct indicator of perinatal mortality and a clear predictor of adult pathologies too. It has been correlated with several causes of mortality in adulthood: low birth weight with diabetes, nephropathy and cardiovascular diseases and high birth weight with autoimmune diseases and cancer. In genome-wide studies, an extended human leucocyte antigen ( HLA) region has been linked to birth weight variation. We focused our attention on the HLA haplotypes marked by HLA-A, HLA-B and HLA-DRB1 polymorphisms in 1206 healthy Caucasian newborns belonging to the Cord Blood Bank of Pavia (Italy) and their mothers, aiming to investigate the association between this restricted HLA region and birth weight variation. In our study, the HLA-B*38;DRB1*13 haplotype showed an ascending trend among centiles addressing to the high foetal weight. The HLA-A*02;B*15 haplotype showed a descending trend among centiles addressing to the low foetal weight. Besides the acknowledged correlation between the HLA-A*02 and HLA-B*15 alleles (as well as low birth weight) and type I diabetes and between the HLA-B*38 and HLA-DRB1*13 alleles (as well as high birth weight) and several autoimmune diseases, we cannot predict if our babies, healthy at birth, will suffer from these pathologies during life. Nevertheless, our data point to the HLA telomeric end for markers linked to the low birth weight and to the HLA centromeric end for markers linked to the high birth weight, thus limiting the region involved in birth weight variation, which still represents a useful predictor of disease risk in adulthood. [ABSTRACT FROM AUTHOR]

Aim: We investigated on parental history and IgE serum level in 2588 consecutive newborns to individuate babies "at risk" of atopy at birth and we analysed the polymorphisms of class III region to evaluate the association with immunogenetic markers of HLA: C4A, C4B, LTA, RAGE and TNFA genes; we performed TNF and IgE receptor (FCERB1) physiologically related gene polymorphisms. Result: 791 babies/2588 (30.6%) were considered "at risk" for atopy and followed-up: 400 had familial history of atopy (at least one parent or sibling), 256 had IgE >0.35 kUA/l at birth and during the follow-up and 135 were positive for both conditions. The allele C4B2 was significantly more frequent in the sample of babies at risk (22.1% vs 10%, p< 0.001). Furthermore, the mean value of IgE at birth in babies carrying the allele C4B2 was 2.26 KUA/l versus 0.74 KUA/l in those not carrying this allele (p=0.01). No significant association emerged for RAGE at the centromeric end of class III region and for LTA, TNFA at the telomeric one. TNFRI, TNFRII and FCERB1 gene polymorphisms also seemed not implicated. Conclusion: Our study confirms that HLA class III region seems involved in familial predisposition to atopy, and C4B gene probably acts as a marker of a more restricted subregion. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate whether polymorphisms of the HLA class II, tumour necrosis factor (TNF) and transporter associated with antigen processing (TAP) genes influence the response toα-interferon in patients with chronic hepatitis C. Twenty-seven sustained responders and 55 non-responders toα-interferon monotherapy were investigated. HLA-DRB1, DQA1, DQB1, TNFA, TNFB, TAP1 and TAP2 alleles were determined by PCR-based molecular techniques. Sustained virological response was defined as undetectable serum hepatitis C virus (HCV) RNA for at least 3 years after the end of treatment. Probability (P) values were corrected for the number of alleles tested (Pc). Viral genotype 1b was more frequent in responders than in non-responders (56% vs. 26%,P = 0.009). HLA-DQB1*02 occurred less frequently in responders than in non-responders (14.8% vs. 29%,Pc not significant). HLA-DRB1*11 and DQB1*0602 were found in 22.2% and 9.3% of responders and in 10.9% and 1.8% of non-responders, respectively (Pc not significant). There was no difference in the distribution of TNF alleles in the two groups. Twenty-four (88.8%) responder patients as compared with 34 (61.8%) non-responders were TAP1*0101 homozygous (Pc not significant). Thus, in European Caucasoids with chronic hepatitis C, we could not demonstrate a strong association between HLA class II, TNF, and TAP gene polymorphisms and response to interferon treatment. [ABSTRACT FROM AUTHOR]

Summary:We evaluated the outcome of 63 children given haematopoietic stem cell transplantation from unrelated donors (URD-HSCT) prospectively selected using DNA high-resolution typing of both HLA class I and class II loci. Thirty patient/donor pairs (48%) were fully matched. Among the others, HSCT was performed in the presence of one (n=22), two (n=9), or three (n=2) HLA disparities. Patients had either malignant (n=46) or non-malignant (n=17) disease. In all cases, graft-versus-host disease (GVHD) prophylaxis consisted of cyclospor-in A, short-term methotrexate and pretransplant anti-thymocyte globulin. The probability of haematopoietic recovery at day 100 was 97%. Two patients experienced primary graft failure. The cumulative probability of grades III-IV acute GVHD and of extensive chronic GVHD equalled 8 and 14%, respectively. A total of 12 patients died of transplant-related complications. The probability of transplant-related mortality (TRM) at 100 and 180 days was 10 and 15%, respectively, whereas the cumulative incidence of TRM was 22%. The probability of GVHD-related mortality equalled 6% at 2.5 years. The overall and disease-free survival rates were 67 and 65%, respectively. URD-HSCT with donor selection based on high-resolution HLA typing is associated with low incidence of both severe acute GVHD and graft failure. The observed outcome is comparable to that of children transplanted from HLA-identical siblings.Bone Marrow Transplantation (2003) 31, 987-993. doi:10.1038/sj.bmt.1704054 [ABSTRACT FROM AUTHOR]

Haematopoietic stem cell transplantation (HSCT) represents the treatment of choice for severe bone marrow failure in patients with Fanconi anaemia (FA). When the donor is a compatible relative, the chance of being cured with an allograft is in the order of 70%. However, for FA children lacking an HLA-identical sibling, the results of HSCT from an alternative donor are less satisfactory because of a higher risk of graft rejection, graft-versus-host-disease (GVHD) and regimen-related toxicity. We report on a 12-year-old girl with FA, who was treated by T-cell-depleted (TCD) peripheral blood HSCT from her haploidentical uncle, using a novel fludarabine-based preparative regimen without radiation. She had rapid engraftment with no toxicity and no GVHD. Progressive recovery of both numbers of lymphocyte and of proliferative response to polyclonal activators occurred over time. At 18 months after transplantation, she is well with 100% donor chimerism and has recovered normal immune function.Bone Marrow Transplantation (2003) 31, 437-440. doi:10.1038/sj.bmt.1703903 [ABSTRACT FROM AUTHOR]

Summary. We conducted a retrospective cohort study to estimate the incidence of major blood-borne agents among Italian blood donors and calculated the risk of infection among blood recipients using the ‘incidence/window period model’. The study was conducted among 46 180 blood donors enrolled in six blood centres between 1994 and 1999. During follow-up, seven new infections were confirmed: three donors seroconverted for anti-human immunodeficiency virus (HIV); two for anti-hepatitis C virus (HCV); and two showed hepatitis B surface antigen (HBsAg) reactivity; no cases of syphilis were observed. The incidence rates per 100 000 person/years were: 4·06 (95% CI: 0·82–11·85) for HIV; 2·41 (95% CI: 0·29–8·70) for HCV; and 2·70 (95% CI: 0·32–9·77) for HBsAg; the incidence for total hepatitis B virus (HBV) infection was 9·77 per 100 000 person/years (95% CI: 1·16–35·36). The estimated risk of an infectious blood unit not being detected was: 2·45 (95% CI: 0·13–12·33) per 1 million units for HIV; 4·35 (95% CI: 0·30–22·39) for HCV; and 15·78 (95% CI: 1·16–84·23) for HBV. Overall, an estimated 22·58 per 1 million units are infected. In Italy, the risk of transfusion-transmitted infections is low and is similar to that in other western countries. The introduction of new more sensitive screening tests could reduce the residual risk of transfusion-transmitted infection by 40–80%. [ABSTRACT FROM AUTHOR]

Non-responsiveness to hepatitis B virus (HBV) vaccine in adults is strongly associated with HLA-C4AQO, DRB1[sup *] 0301,DQB1[sup *]02 haplotype. This association was also demonstrated in neonates who failed to mount a humoral response to challenge with HBV vaccine. About 4% of vaccinated newborns do not reach a protective antibody level (≤ 10 mlU/ml) at seroconversion and 0.4% is a non-responder even after receiving a fourth dose of vaccine (true non-responders (TNR)); while 3.6% achieved an antibody level ≥ 10 mlU/ml (slow responders (SR)) only when reboostered with the fourth dose. In the present study we extend the vaccination and HLA typing to 91 family members of probands to understand better the possible parent-to-child transmission of this trait. A transmission disequilibrium test (TDT), performed in 27 families, showed that the C4AQO allele was almost always transmitted to probands, both TNRs and SRs. Although not statistically significant, the highest LOD score was obtained with C4A locus: 1.58. These results suggest the presence of a region regulating immune response against HBV vaccination near to or coincident with the C4A locus. Genes and Immunity (2001) 2, 367-372. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the cycling status of cord blood (CB)-derived colony-forming cells (CFC) and long-term culture-initiating cells (LTC-IC), and their recruitment into the S-phase of the cell cycle. By using the cytosine arabinoside (Ara-C) suicide approach, we found that only small proportions of both CFC and LTC-IC were in the S-phase of the cell cycle. These estimates were confirmed by flow cytometric DNA analysis, which showed that 96 ± 2% of CB-derived CD34+ cells were in G[sub 0]/G[sub 1] and only 1.6 ± 0.4% in the S-phase. Staining of CD34+ cells with an antistatin monoclonal antibody, a marker of the G[sub 0] phase, indicated that among CD34+ cells with a flow cytometric DNA content typical of the G[sub 0]/G[sub 1] phase 68 ± 7% of cells were in the G[sub 0] phase of the cell cycle. Incubation (24 h) with interleukin 3 (IL-3), recombinant human stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF) significantly increased the proportion of cells in the S-phase for both CFC and LTC-IC without inducing any loss in numbers. Flow cytometric DNA analysis also showed an increase in CD34+ cells in the S-phase upon continuous exposure to these cytokines. Our findings indicate that: (i) very few CB-derived CFC or LTC-IC were in the S-phase of the cell cycle; (ii) a substantial amount of CD34+ cells with a flow cytometric DNA content typical of the G[sub 0]/G[sub 1] fraction was cycling, as found in the G[sub 1] phase of the cell cycle; and (iii) 24-h incubation with IL-3, SCF and G-CSF could drive a proportion of progenitor cells into the S-phase without reducing their number. These data might be useful for gene transfer protocols and the ex vivo expansion of CB-derived progenitor cells. [ABSTRACT FROM AUTHOR]

Ten patients with acute leukemia (AL) in early relapse after allo-BMT were treated with a modified MEC (mitoxantrone, etoposide and Ara-C) regimen followed by donor PBPC collected after mobilization with G-CSF. Seven patients achieved CR or had normal hemopoietic reconstitution: two had an early relapse at days +53 and +48, two patients died from acute GVHD at days +31 and +96, one died of interstitial pneumonia at day +55, and two patients experienced long-term survival. One patient with refractory disease and nodal involvement who did not respond to the first BMT had overt expansion of the leukemia at day +36; one patient with Ph+ ALL and one with ANLL evolving from MDS, both with skin involvement, had blast cells in peripheral blood at day +27 and +26, respectively. Transient cytopenia occurred in all patients; a normal granulocyte and platelet count was achieved within 3 weeks in all patients but one; acute GVHD occurred in six patients, and four had chronic GVHD. This approach is feasible in patients in early relapse after allo-BMT. It assists prompt re-establishment of normal donor hematopoiesis avoiding the prolonged cytopenia observed after donor lymphocyte infusion in AL patients relapsed after allo-BMT. [ABSTRACT FROM AUTHOR]

Abstract: The ‘stem cell burden’ hypothesis represents a plausible explanation for the association between birth-weight and the risk of breast cancer in adulthood. The size of the overall stem cell pool would be expected to affect organ size and consequently birth-weight, making birth-weight a proxy for the overall number of fetal stem cells. As stem cells are self-renewing, the greater their number is at birth, the higher will be the chance that one of them will undergo carcinogenesis over the years. To investigate the correlation between birth-weight and stem cell burden, we examined the cord blood hematopoietic CD34+ stem cell population as an indicator of the overall fetal stem cell number. We measured both the CD34+ level (by flow cytometry) and the CD34+ proliferative potential (by the GM-CFU culture), in a sample of 1037 healthy newborn cord blood donors. We found that heavier babies had a significantly greater CD34+ stem cell concentration (p <0.001) and a higher GM-CFU number than lighter babies (p <0.001). Thus, a high birth-weight was positively associated with a high concentration of CD34+ stem cells and also with a qualitatively higher “stemness” of this pool. Therefore, our data support the theory that birth-weight reflects the number of fetal stem cells. [Copyright &y& Elsevier]

The article discusses the benefit of blood group genotyping in cord blood (CB) banking. It states that blood genotyping is used to validate polymorphisms and to enhance CB banking. It mentions that genotyping is required for the quality control system in an inter-Laboratory. Moreover, genotyping prevents anti-D alloimmunization and manages transfused recipients.

High-resolution polymerase chain reaction using sequence-specific primer typing of the HLA-DRB1 gene of an Italian patient waiting for unrelated bone marrow transplantation revealed a new allelic variant of HLA-DRB1*13. Sequencing the exon 2 of DRB1* gene demonstrated a G→C transition at the nucleotide 216 resulting in a silent mutation at codon 72: CGG→CGC. The closest sequence was the HLA-DRB1*1302 and the new allele was named HLA-DRB1*13022. This variant was carried by the haplotype HLA-A*24; Cw*0702; B*39; DRB1*13022; DRB3*0301; DQA1*0102; DQB1*0604 as demonstrated by a family study. [ABSTRACT FROM AUTHOR]

We compared the immunogenetic data from 2666 patients affected by HLA-related autoimmune diseases with those from 4389 ethnically matched controls (3157 cord blood donors CBD, 1232 adult bone marrow donors BMD), to verify the appropriateness of HLA typing requests received in the past decade. The frequency of HLA-B¿27 phenotype was 10.50% in 724 ankylosing spondylitis, 16.80% in 125 uveitis (3.41% BMD, 4.24% CBD, P < 0.0001); HLA-B¿51 allele was 15.57% in 212 Behçet's disease (12.91% BMD, 9.88% CBD, P < 0.0001); the HLA-DRB1-rheumatoid arthritis (RA) shared epitope was 13.72% in 554 RA (10.85% BMD, 13.48% CBD, P = 0.016); the carriers of almost one of HLA-DQB1 susceptibility alleles were 84.91% in 795 celiac disease (CD) and 59.37% in 256 insulin-dependent diabetes mellitus (IDDM) (46.06% in 875 CBD, 42.75% in 662 BMD P < 0.0001). Overall, our results show that the HLA marker frequencies were higher in patients than controls, but lower than expected from the literature data (excluding CD and IDDM) and demonstrate that, in complex immunogenetic conditions, a substantial number of genetic analyses are redundant and inappropriate, burdening to the public health costs. For this reason, we suggest the Italian Scientific Society of Immunogenetics to establish guidelines to improve the appropriateness of typing requests. [ABSTRACT FROM AUTHOR]