A new HLA-DPB1 allele, HLA-DPB1*142:01, identified in a Peruvian organ donor.

The new HLA-DPB1*142:01 allele differs from DPB1*26:01:02 and DPB1*56:01 at codons 65 (I65>L65) and 35 (F35>Y35), respectively.

Sequencing of a single HLA-B genotype including two rare alleles allows the detection of a new allele, B*44:130.

The novel HLA-B*44:130 allele was found in a Spanish donor. B*44:130 differs from B*44:40 by four nucleotide changes at codons 11, 12 and 24, producing three amino acid replacements, 11A>S, 12M>V and 24T>S.

HLA-B*0777 allele differs from B*0707 by a single residue in the antigen binding groove.

Human leukocyte antigen (HLA) class I sequence-based typing (SBT) for hematopoietic unrelated donor searching in a Romanian Caucasian patient showed the presence of a novel HLA-B allele defined as B*0777. HLA-B*0777 has two nucleotides changes at the same codon from B*0707, resulting an amino acid replacement 99Y > 99S.

Allelic distribution and the effect of haplotype combination for HLA type II loci in the celiac disease population of the Valencian community (Spain).

The association between human leukocyte antigen (HLA) class II antigens and celiac disease (CD) was analyzed in a Spanish population. No association with DRB1*04 and DQB1*0302 was noted. The main associated haplotype (70.8%) was DRB1*03-DQB1*0201-DQA1*0501(DR3-DQ2), followed by DRB1*07-DQB1*0202-DQA1*0201 (DR7-DQ2) haplotype, which is associated with DRB1*11-DQB1*0301-DQA1*0505 (DR11-DQ7). The combinations of DR3-DQ2 with DR7-DQ2, and DR7-DQ2 with DR11-DQ7, present a twofold risk compared with each haplotype in homozygosis. An independence test in DR3-DQ2 haplotype found that association with CD was attributable to the whole haplotype, but for DR7-DQ2 was secondary to DQB1/DQA1. There is no need of a double gene dosage to increase the risk. CD-associated alleles typing demonstrates a very high negative predictive value to exclude CD in risk groups.

Donor screening for hepatitis B virus infection in a cell and tissue bank.

BACKGROUND AND OBJECTIVES: Hepatitis B virus (HBV) has been transmitted by tissue transplantation. In order to reduce the risk of HBV transmission, testing for antibody to HBV core antigen (anti-HBc) is used in addition to testing for hepatitis B surface antigen (HBsAg) in many blood centers and tissue banks. DESIGN AND METHODS: We retrospectively analyzed the results of HBV assays in tissue donors. All tissue donors were tested for HBsAg and anti-HBc. All anti-HBc positive sera were tested for the antibody to HBsAg (anti-HBs). From July 2006, an HBV nucleic acid testing (NAT) assay was also performed. RESULTS: A total of 6855 tissue donors from January 1999 till July 2007 were tested for HBV assays: 4756 women and 2099 men. Positive HBsAg was found in 23 (0.36%) living donors, while no multiorgan or cord blood (CB) donor was found to be positive for HBsAg. Positive anti-HBc was found in 80 multiorgan donors (12.94%), 599 living donors (17.84%), and 103 CB donors (3.57%) (P<0.005), while isolated anti-HBc was found in 12 multiorgan (1.94%), in 126 living tissue donors (3.75%), and in 8 CB donors (0.28%). A total of 1310 donors were analyzed for single-sample DNA HBV NAT assay. DISCUSSION: We consider that anti-HBc and NAT assays must both still be performed in addition to HBsAg assay for HBV screening in tissue donors. All these tests will be useful in order to define an algorithm for safe and efficient management of the tissue bank.

Pretransplant donor-specific HLA antibodies detected by single antigen bead flow cytometry: risk factors and outcomes after kidney transplantation.

BACKGROUND: The clinical significance of pretransplant donor-specific antibodies (pre-Tx DSAs) detected by single antigen bead flow cytometry (SAB-FC) remains unclear. Our aim was to investigate the impact that pre-Tx DSAs detected by SAB-FC have on the early and late clinical outcomes. PATIENTS AND METHODS: We retrospectively tested stored frozen pre-Tx sera from 222 deceased-donor kidney transplants performed between November 1997 and November 2006. All patients had a negative complement-dependent cytotoxicity (CDC) cross-match with the donor. Median follow up was 5.1 years. RESULTS: Twenty-two (10%) patients had pre-Tx HLA antibodies detected by CDC. Pre-Tx HLA antibodies were detected using SAB-FC in the sera of 46 (20.7%) patients; 36 (16.2%) of them presented pre-Tx DSAs, 18 had class I antibodies, 9 class II, and 9 patients presented both classes. Mean pre-Tx DSA class I/II was 2360/1972 (MFI) mean fluorescence index in non CDC-sensitized patients. Pre-Tx DSAs were associated with female sex, retransplants, and pretransplant transfusions. Patients with Pre-Tx DSAs more than 1000 MFI and negative CDC screening presented a higher percentage of delayed graft function (61.1% versus 38.9%), more episodes of acute vascular rejection (33.3% versus 13.7%), and chronic rejection as the cause of allograft failure (22.2% versus 9.7%) compared with non-pre-Tx DSAs patients. Five-year allograft survival was significantly worse in patients with pre-Tx DSA (68.5% versus 82%, P = .006) and in patients with pre-Tx DSA class II more than 1000 MFI (43% versus 82%, P = .009). We didn't find differences in patient survival. DISCUSSION: Pre-Tx DSAs detected by SAB-FC were more frequent in female recipients, and they were associated with acute vascular and chronic rejection and a poorer graft outcome.

HLA class II polymorphisms in Spanish melanoma patients: homozygosity for HLA-DQA1 locus can be a potential melanoma risk factor.

BACKGROUND: The association of melanoma with HLA class II loci is under extensive debate. Different investigators have found discrepant results due to, at least in part, sample size, patient series heterogeneity, choice of control population and differences in the techniques employed for the detection of HLA antigens and alleles. OBJECTIVES: This study was designed to analyse the possible association of melanoma with HLA class II loci with regard to different clinic pathological factors and to investigate other risk factors for melanoma susceptibility, such as HLA homozygosity. PATIENTS AND METHODS: HLA-DRB1, -DQA1 and -DQB1 genotyping was performed for 117 eastern Spanish patients presenting with primary melanoma. RESULTS: Although there were no significant alterations in the phenotypic frequencies of HLA-DQA1, -DQB1 or -DRB1 alleles in any subgroup of patients when compared with controls, patients exhibited a statistically significant increase in HLA-DQA1 homozygosity rate. This DQA1 homozygosity-specific association was particularly dependent on some features in melanoma patients such as light hair colour, skin type I or II, early age at diagnosis, absence of atypical naevi, or abscence of atypical naevus syndrome phenotype (aetiological fractions about 10-20%). Analysis of homozygosity for single DQA1 alleles showed an increased homozygosity rate for DQA1*0505 and DQA1*0301 in comparison with controls. These DQA1 alleles are in strong linkage disequilibrium with DQB1*0301 in white populations, and DQB1*0301 homozygous individuals were significantly increased in red in or fair-haired patients (relative risk 5.65). CONCLUSIONS: Our results indicate that the contribution of HLA class II alleles to primary melanoma incidence is not significant in the Spanish population. However, homozygosity for the HLA-DQA1 locus (and, perhaps, for the HLA-DQB1*0301 allele) might be considered a potential risk factor for developing melanoma depending on the person's genetic background and, perhaps, on certain environmental conditions.

A new, fast, and simple DNA extraction method for HLA and VNTR genotyping by PCR amplification.

In the present study a new DNA extraction method is described. The new protocol, which uses caprylic acid for isolating DNA, is technically simple and very fast, as it enables us to obtain DNA from peripheral blood in only 10 minutes. Moreover, DNA preparations obtained with this procedure can be effectively used for HLA class II and variable number tandem repeat genotyping by polymerase chain reaction, so the new method is well suited for routine clinical use in any type of analysis requiring DNA typing for individual characterization.

Post-transfusion purpura as the main manifestation of a trilineal transfusion reaction, responsive to steroids: flow-cytometric investigation of granulocyte and platelet antibodies.

We report a typical case of post-transfusion purpura (PTP) due to anti-PlA1 in a 65-year-old woman. Serological studies were carried out using flow cytometry (FCM). The patient also developed red cell alloantibodies that produced a delayed hemolytic transfusion reaction (DHTR) and broad HLA antibodies. Treatment with high-dose intravenous IgG (HDIgG; a first-generation preparation) was ineffective, but a course of steroids resulted in a rapid increase in the the platelet count.

[Alloimmune neonatal neutropenia: flow cytometry study of the 1st patient described in Spain with identification of an anti-NA1]. / Neutropenia neonatal aloinmune: estudio por citometría de flujo del primer caso descrito en España con identificación de un anti-NA1.

A strong antibody was found in a mother (first pregnancy) who had a severe neutropenic baby. The father's granulocytes were typed by flow cytometry as NA1+, NA2+, NB1+, ND1+ and the mother as NA1-, NA2+, NB1+ and ND1+. The antibody was identified as anti-NA1 by us, and confirmed later by a reference laboratory. The serum reacted with 54.8% of the 31 donors tested. The same antibody was found in the child's serum 35 days after birth, and the reactivity was stronger than in the mother's serum. The HLA-DR, DQ from the mother was DR3, DR7; DR52, DR53; DQ2. The baby's granulocytes were recovered slowly over a four-month period, but the course was benign without any specific treatment. Five months after birth, with recovery, the child's serum became negative and his granulocytes were confirmed as NA1+. Due to the difficulties in fully diagnosing and working with granulocytes we suspect that there are undetected cases; only one case has been recorded in Spain before.

A monolayer coagglutination microplate technique for typing red blood cells.

BACKGROUND AND OBJECTIVES: Serologic agglutination tests have the disadvantage of lack of an objective endpoint that can be easily read and quantitated. We have developed a new method for ABO and Rh typing based on producing a red blood cell (RBC) monolayer on microplates and the mixed hemagglutination reaction. MATERIALS AND METHODS: We have employed a new red cell fixation buffer to prepare the RBC monolayer. As the technique for grouping, we used a mixed agglutination reaction between the RBC monolayer and the RBCs to be typed. RESULTS: Compared with an automated hemagglutination system in 34,519 samples, the method is shown to be more sensitive, free of false positive reactions, and cost-effective. CONCLUSIONS: The microplate coagglutination method is accurate and lower in cost than conventional methods.

Isoimmune neonatal neutropenia caused by Fc gamma RIIIb antibodies in a Spanish child.

BACKGROUND: Fc gamma RIIIb deficiency is a rare defect in which neutrophils do not express Fc gamma RIIIb and therefore the individuals with this defect have an NA null phenotype. Soluble Fc gamma RIII in plasma is severely decreased and almost undetectable. During pregnancy, Fc gamma RIIIb deficiency may cause the formation of maternal Fc gamma RIIIb antibodies, which leads to an isoimmune neonatal neutropenia. The first known case of isoimmune neonatal neutropenia caused by these antibodies in a Spanish child was identified. CASE REPORT: A newborn infant was severely affected by omphalitis; analysis of his blood showed an absolute neutropenia, but he responded well on intravenous immunoglobulin therapy. The maternal antiserum reacted strongly with all tested Fc gamma RIIIb-positive neutrophils. A family study showed that the infant's mother, one of the mother's sisters, and her mother were Fc gamma RIIIb deficient. No neutrophil antibodies were found in the plasma from these other Fc gamma RIIIb-negative women, although both had had numerous pregnancies. The three women were healthy, but one had recurrent otitis. DNA analysis of the family showed the absence of both Fc gamma RIIIB genes in the three Fc gamma RIIIb-negative women. The father of the child and all the children of the Fc gamma RIIIB gene-deficient women were shown to lack one of the Fc gamma RIIIB genes. CONCLUSION: A new case of isoimmune neonatal neutropenia caused by anti-Fc gamma RIIIb is identified. The family study indicates that the Fc gamma RIIIb deficiency is a hereditary genetic defect. In accordance with the location of Fc gamma RIIIB on chromosome 1, an autosomal pattern of inheritance of the Fc gamma RIIIB-deficient allele was observed.

HLA-DQA, -DQB and -DRB allele contribution to narcolepsy susceptibility.

The association of narcolepsy with HLA class I antigens and HLA class II alleles was studies in a series of Spanish narcoleptic patients. The haplotype DRB1*1501-DRB5*0101-DQA1*0102-DQB1*0602 was found to be significantly associated with the disease, while the haplotype DRB1*0701-DRB4*01-DQA1*0201-DQB1*02 might confer a slight protective effect against narcolepsy. Gene dose-effect was not seen in any of the involved alleles, and linkage disequilibrium between the positively associated alleles was found to be stronger in patients than in controls. Statistical analysis applied to identify the HLA allele truly responsible for the association did not clearly discriminate between the contribution of DRB1*1501 and that of DQB1*0602, but it proved that the association with DQA1*0102 is secondary to that with DRB1*1501/DQB1*0602. Analysis of the diagnostic value of typing for the narcolepsy-associated alleles demonstrated a very high negative predictive value and revealed that this test can be convenient for exclusion of narcolepsy in cases when the diagnosis is not evident after clinical evaluation and the marker haplotype is absent. Finally, a family study indicated that narcolepsy is a multifactorial disorder that involves HLA genes under an incomplete penetrance model, with possible influences from environmental factors or other genes different to HLA genes.