HLA-B*38:55Q: a new alternatively expressed allele identified in a three-generation Italian family.

The new allelic variant HLA-B*38:55Q differs from the closest related B*38:01:01 by one nucleotide substitution at position 373 in exon 3 (TGC>CGC). This results in a difference of one amino acid at residue 101 of the HLA-B heavy chain, from a neutral-polar Cys to a basic-polar Arg, thus impairing disulphide bridge formation in the alpha-2 domain. This alteration of the secondary structure probably affects the maturation of the heavy chain and the level of surface expression, making the HLA-B*38:55Q undetectable by standard serological typing.

For anti-HLA-specific donor antibodies detection by flow cytometry cytotoxic crossmatches comparison of methods.

Anti-HLA-specific donor antibodies induce rapid, irreversible destruction of the transplant (hyperacute rejection) that today happens rarely due to immunologic studies-prospective crossmatch-of patients awaiting the kidney graft. The usual approach for pretransplant donor/recipient evaluation is based on 2 methods: (1) the cytotoxic complement crossmatch (CDC) and (2) the flow cytometric crossmatch (FCX). The CDC crossmatch is positive when complement-fixing antibodies are present, an absolute contraindication to kidney transplantation. The more sensitive FCX-positive crossmatch detects low concentrations of unable to fix performed antibodies complement. It is an "index" of possible damage due to accelerated rejection. The target of our study was to develop a cytotoxic flow cytometry crossmatch (cFCX) that detected cytotoxic antibodies move sensitively than the traditional CDC method and also was less subjective and more standardized for interpretation studying sera from 23 patients; the cFCX showed the requested efficiency characteristics even in an emergency. In addition, the new method permited one to calculate a cutoff for positivity (average value of the negative control + 2 standard deviations), assuring an "objective" interpretation of the results that agreed with the CDC but was more sensitive and accurate allowing solution of ambiguous results for cases of "doubt"-positive CDC crossmatch. Furthermore, our aim was to correlate the effect of the strength of the anti-HLA antibodies determined by mean fluorescence intensity value of LabScreen Single Antigen beads with results of CDC, cFCX, and FCX methods.

Identification of the novel HLA-B*50:18 allele variant in an Italian unrelated bone marrow donor.

The HLA-B*50:18 allele differs from the closest related B*50:01:01 by one nucleotide substitution at position 454 in exon 3.

Sequence-based typing identification of the novel HLA-A*24:135 variant in a Maldivian family with a bone marrow patient.

We describe the identification of the novel HLA-A*24:135 allele [nucleotide 397 (T→C) in exon 3, Phe→Leu at codon 109 in α2 domain, compared with A*24:02:01] by sequence-based typing (SBT).

Evaluation of serum sCD30 in renal transplantation patients with and without acute rejection.

Despite new immunosuppressive approaches, acute rejection episodes (ARE) are still a major cause of early kidney dysfunction with a negative impact on long-term allograft survival. Noninvasive markers able to identify renal ARE earlier than creatinine measurement include sCD30. We sought to establish whether circulating levels of sCD30 in pretransplantation and posttransplantation periods were of clinical relevance to avoid graft damage. Quantitative detection of serum sCD30 was performed using an enzyme-linked immunosorbent assay. Our results demonstrated that the mean concentrations of sCD30 were significantly higher in the sera of renal transplant recipients with ARE (30.04 U/mL) and in uremic patients on the waiting list (37.7 U/mL) compared with healthy controls (HC; 9.44 U/mL), but not nonrejecting patients (12.01 U/mL). Statistical analysis revealed a strong association between high sCD30 levels in posttransplantation sera and ARE risk. This study suggested that sCD30 levels were a reliable predictor of ARE among deceased-donor kidney recipients.

HLA-G 14-bp insertion/deletion polymorphism in kidney transplant patients with metabolic complications.

HLA-G, a nonclassical HLA molecule with limited polymorphism has immunomodulating/tolerogenic properties. The most common polymorphism of HLA-G is a deletion/insertion of 14 bp, located at the 3'UTR region of the gene (exon 8). This polymorphism is associated with modifications of mRNA stability that can lead to variations of membrane versus soluble HLA-G expression. HLA-G may be involved in the clinical outcomes of transplantation, as evidenced by studies in hematopoietic cell transplantation. We evaluated the possible prognostic importance of 14-bp polymorphisms of HLA-G among kidney transplantation patients. Using polymerase chain reaction amplification we genotyped 124 patients (mean organ survival: 878.95 +/- 595.12 days; range = 1-2565) and 98 control individuals representative of the Italian population. Products were visualized by electrophoresis on agarose gels. The results showed no differences between patients and controls. Twenty-nine patients with acute or chronic rejection or in whom clinical conditions required the use of steroid bolus treatments also showed no association with HLA-G 14-bp genotypes or alleles. The subset of patients with dyslipidemia during follow-up showed a significant decrease among the HLA-G-14/-14 genotype, compared with heterozygous (+14/-14) and nondeleted homozygous (+14/+14) genotype patients (P(c) = .03). These preliminary data showed that HLA-G 14-bp genotypes, although not predictive of rejection, may be useful to identify individuals at risk for the development of posttransplant complications.

Interferon-alpha therapy and anti-human leukocyte antigen antibodies in hepatitis C virus-positive patient: case report.

Interferon-alpha (IFN-alpha) is currently the only treatment for patients with chronic hepatitis C. Yet it can induce acute renal transplantation rejection possibly by stimulating humoral responses. We tested patient sera for detection of donor-specific anti-human leukocyte antigen (HLA) antibodies observing an increased panel-reactive antibodies value after IFN-alpha therapy. Then, we also investigated whether antiviral treatment with IFN-alpha was related to an increased and/or different production of class I and class II anti-HLA antibodies. Patient sera analysis performed by a cytofluorimetric method using flow PRA tests showed the appearance of new HLA-antibody specificities. This study underlined that INF-alpha therapy modifies a patient's immune profile; hence, it is recommended to confirm HLA-antibody specificities after treatment in order to protect recipients from enhanced rejection risk owing to a false-negative donor-specific cross-match.

CD1a and CD1e allele frequencies in an Italian population from the Abruzzo region.

CD1 is a small family comprising 5 MHC-like genes located on chromosome 1 and encoding glycoproteins termed CD1a, CD1b, CD1c, CD1d and CD1e. They are expressed mainly on the surface of dendritic cells, monocytes and some thymocytes and are specialized in presenting lipid antigens to T lymphocytes. The structure is similar to that of MHC class I molecules with 3 globular domains and the Beta2-microglobulin. It has been shown that all five human CD1 genes exhibit a limited number of polymorphisms in the alpha1 domain whose effects are still unknown. CD1e results to be the most polymorphic isoform with six CD1e alleles (01, 02 in exon 2 and 03, 04, 05, 06 in ex3) described to date. At this moment, few investigations on the allele frequencies of the CD1 genes have been reported and all additional information improves our knowledge on this new class of antigen-presenting molecules. In order to study possible allelic variations of exon 2 of human CD1a and CD1e genes, we analyzed, by a sensitive technique, the sequence-based typing (SBT), 114 DNA samples from unrelated healthy Italian individuals from the Abruzzo region. Our experimental findings indicate that the allele frequency distribution of both CD1a and CD1e genes is in accordance with that observed in other geographic areas and did not identify any new allele, thus confirming a very low polymorphism.

Genetic predisposition to rheumatoid arthritis in a Tuscan (Italy) ancient human remain.

Rheumatoid arthritis (RA) is currently believed to have originated in America, and after the discovery of this continent in 1492, to have been exported to the Old World. We evaluated the genetic predisposition to RA in the "Braids Lady" from Arezzo (Italy), a partially mummified woman's body dating back to the end of 1500 AD which presents the anatomical and pathological features of this disease. The study of the polymorphic HLA-DRB1 locus, which includes alleles strongly associated with RA onset, has received much attention over recent years, especially the loci codifying for the DR1 and DR4 antigens, widely represented in the Mediterranean population, and for DR14, widespread among Native Americans. Molecular analysis was performed on extracts of DNA from the mummy, firstly from histological bone sections and then from the whole bone. Two different HLA typing techniques, PCR-sequence-specific oligonucleotides (PCR-SSO) and PCR-sequence-specific primers (PCR-SSP), were employed to identify HLA-DRB alleles. Both genotyping methods showed that the "Braids Lady" carried the DRB1*0101 allele, the serological equivalent of the DR1 antigen. Although the possession of RA risk factor genes cannot be considered a diagnostic marker, the positive result of the Italian mummy for DRB1*0101 and the RA features present, support the idea that this pathology was present in the Old World from at least the mid-16th century. A pathogenetic hypothesis of RA which might well explain its worldwide diffusion is the "molecular mimicry", resulting from a cross-reactive antibody response between certain microbial antigens and shared epitopes of specific HLA-DR1, DR4 and DR14 susceptibility alleles, the frequency of which varies among different ethnic groups.

HLA DR/DQ alleles and risk of type I diabetes in childhood: a population-based case-control study.

The objective was to evaluate HLA DR/DQ alleles and their risk factor for type 1 diabetes in the Abruzzo region (central Italy). Sixty incident cases from the Abruzzo region were studied together with 120 unrelated control subjects living in the same administrative areas. The relative risk of diabetes associated with the alleles under study was calculated by deriving the odds ratio (OR) maximum likelihood estimates and their 95% confidence intervals (CI) by the exponentiation of the logistic regression beta-parameter. The combination DRB1*03/DQA1*0501/DQB1*0201 was found in 20.0% of patients and 7.1% of the control subjects, conferring an OR of 4.04 and a CI of 1.97-8.49. The combination DRB1*04/DQA1*0301/DQB1*0302 was found in 23.3% of diabetic patients and 6.7% of controls, giving an OR of 5.69 and a CI of 2.77-12.05. DRB1*11/DQA1*0505/DQB1*0301 and DQA1*0505/DQB1*0301 were negatively associated with type 1 diabetes (OR=0.27, CI 0.11-0.57; OR=0.07, CI 0.02-0.19). The DQA1 genotype at risk was found to be DQA1*0301/DQA1*0501: OR=23.80, CI 2.97-190.89, as it occurred with the highest frequency in the patient group. The DQB1 genotype at risk was found to be DQB1*0201/DQB1*0302, which occurred in 13.3% of patients but in only 1.1% of the control group (OR=29.75, CI 5.36-549.25). Our results shed further light on the risk of development of this disease during a specific time period in an area where the overall incidence of type 1 diabetes is known.