Polynesians living on the island of Mauke in the Cook Island group were typed for HLA-A and -B locus antigens. The Mauke population has restricted HLA polymorphism, with five A-locus antigens and four B-locus antigens accounting for a majority of the HLA phenotypes. Although some differences in antigen frequency were found when Mauke Islanders were compared with Polynesians from Easter Island and Samoa, the Mauke Islanders were closer in their HLA antigenic profile to polynesians than to Melanesians.

Background The DiGeorge syndrome is a congenital disorder that affects the heart, parathyroid glands, and thymus. In complete DiGeorge syndrome, patients have severely reduced T-cell function.Methods We treated five infants (age, one to four months) with complete DiGeorge syndrome by transplantation of cultured postnatal thymus tissue. Follow-up evaluations included immune phenotyping and proliferative studies of peripheral-blood mononuclear cells plus biopsy of the thymus allograft. Thymic production of new T cells was assessed in peripheral blood by tests for T-cell-receptor recombination excision circles, which are formed from excised DNA during the rearrangement of T-cell-receptor genes.Results After the transplantation of thymus tissue, T-cell proliferative responses to mitogens developed in four of the five patients. Two of the patients survived with restoration of immune function; three patients died from infection or abnormalities unrelated to transplantation. Biopsies of grafted thymus in the surviving patients showed normal morphologic features and active T-cell production. In three patients, donor T cells could be detected about four weeks after transplantation, although there was no evidence of graft-versus-host disease on biopsy or at autopsy. In one patient, the T-cell development within the graft was demonstrated to accompany the appearance of recently developed T cells in the periphery and coincided with the onset of normal T-cell function. In one patient, there was evidence of thymus function and CD45RA+CD62L+ T cells more than five years after transplantation.Conclusions In some infants with profound immunodeficiency and complete DiGeorge syndrome, the transplantation of thymus tissue can restore normal immune function. Early thymus transplantation - before the development of infectious complications - may promote successful immune reconstitution. (N Engl J Med 1999;341:1180-9.) (C)1999, Massachusetts Medical Society.

Human interferon-alpha (IFNalpha) and IFNbeta are administered for treatment of several diseases, including viral infections, malignancies, and multiple sclerosis (MS). IFNalpha therapy has been associated with the production of autoantibodies and the development of a variety of autoimmune disorders, including polyarthritis. This report describes the development of seronegative, symmetric polyarthritis in a patient with relapsing-remitting MS, after 8 weeks of therapy with IFNbeta1a. HLA phenotyping analysis of the patient revealed the presence of HLA-DRB1*0404, an allele known to be associated with the development of rheumatoid arthritis. Therefore, IFNbeta1a may have induced arthritis in a patient who was genetically predisposed to develop arthritis on the basis of HLA determinants. The English-language literature regarding IFNalpha- and IFNbeta-induced polyarthritis is reviewed, and possible mechanisms for IFNalpha- and IFNbeta-induced autoimmunity, including the contribution of HLA determinants and nitric oxide overproduction, are discussed.

ROP trays containing patient serum samples and distributed by the South-Eastern Organ Procurement Foundation (SEOPF) were instituted to increase the likelihood of transplanting potential renal recipients who are highly sensitized to HLA antigens. This study examines kidney distribution and transplant outcome to assess equitable placement and clinical function post transplant with and without the use of ROP trays. Data were collected over a 26-month period on the distribution of kidneys from 328 consecutive SEOPF donors from whom at least 1 kidney was procured. Shared kidneys were placed via the UNOS and SEOPF-variance computer match programs. Of 656 kidneys, 596 were placed into 582 recipients; 60 were not used. ROP trays were used in placement of 492 kidneys and were not used for placement of 104 kidneys. Outcome was determined for 435 kidneys transplanted into SEOPF recipients. Only 33 (6.9%) recipients with ROP tray use and 10 (9.8%) without were sensitized to HLA. A 10% increase in placement to the originally intended recipient was seen with ROP tray usage over kidneys placed without ROP tray use (p < or = 0.025). Recipients matched using ROP tray data averaged 29 positions higher on the match printout. There was no difference in tray use regarding placement of kidneys within or outside the donor's local UNOS region, nor was there a difference in mean HLA match of transplant pairs with and without ROP tray use, 3.2 and 3.1 antigens, respectively. Cold ischemia time was similar, 22.9 and 23.6 h, respectively, for kidneys placed with and without ROP trays. At post-transplant discharge, there were no differences in patient status, graft failure, rejection treatment, dialysis need, or urine output whether or not ROP trays were used. Significantly, however, plasma creatinine at discharge and at 12 months was lower for those placed with ROP trays (2.5 mg/dl and 1.7 mg/dl) vs (3.1 mg/dl and 1.9 mg/dl), respectively. During this time period, all kidneys transplanted with use of ROP trays functioned as well or better than those transplanted without ROP tray placement. Thus, the use of ROP trays appeared to have a beneficial effect in getting more recipients of higher priority transplanted with equivalent, if not better, graft function.

BONE MARROW TRANSPLANTATION FOR SEVERE COMBINED IMMUNODEFICIENCY: ANALYSIS AT 15 YEARS ♦ 40

Transplantation of cultured postnatal human thymus was performed in a patient with complete DiGeorge syndrome. Biopsy of the graft 3 mo after implantation revealed normal CD1+ thymocytes in thymic cortical epithelial regions and CD1- thymocytes in thymic medullary epithelial regions, respectively. HLA analysis of graft thymocyte and thymic microenvironment components demonstrated that developing thymocytes and thymic macrophages were recipient derived, while thymic epithelial components were of donor origin. The patient, who initially had no T cells and had profoundly defective T cell function, developed normal T cell responses to mitogens and Ags, tolerance to donor in a mixed lymphocyte reaction, and normal Ab titers after tetanus toxoid and pneumovax immunization. Thus, transplantation of cultured postnatal human thymic tissue in humans can form functional chimeric thymic tissue, and may provide a strategy to reconstitute the peripheral T cell pool in select congenital and acquired immune deficiency syndromes.

Purine nucleoside phosphorylase deficiency is an inherited disease of purine metabolism characterized clinically as combined immunodeficiency. The molecular defects have been published for 4 different alleles in 3 patients. We report four new mutations including two amino acid substitutions, A 174P and G190V, a single codon deletion, ΔI129, and a point mutation in intron 3 which leads to aberrant splicing and creation of a premature stop codon in exon 4 (286 -18G→A). Of the previously reported mutations, E89K was found in one additional patient, and R234P was found in 3 unrelated patients, making R234P the most common mutation reported to date in this disease. Hum Mutat 9:118–121, 1997. © 1997 Wiley-Liss, Inc.

In the United States, allocation of cadaveric kidneys is federally regulated and based on the concept of equal access to all patients, regardless of race, sex, age, or socioeconomic status. Nevertheless, it has been widely reported that African American patients with renal disease wait longer for kidney transplantation and, once transplanted, have poorer graft survival. We have assessed immunogenetic factors that may contribute to ethnic differences in allograft survival by examining the distributions of ABO blood groups, HLA antigens and haplotypes, percent reactive antibody (PRA), age, and gender in our local patient population. Approximately 62% of patients at our transplant center waiting for renal transplantation are African American; 39% are female. Age distribution is comparable to that reported nationally. ABO blood groups of patients on the waiting list are distributed similarly to those reported nationally for other renal patients. Sensitization to HLA antigens, through either blood transfusion, prior transplant, or pregnancy, has been strongly associated with poorer graft survival. Although, as expected, distribution of PRA was significantly different for males versus females at one time point, it did not differ between ethnic groups in our patient population. HLA polymorphism was assessed by comparisons of HLA allele and haplotype frequencies determined by analyses of African American and Caucasian families typed in our program since 1991. Haplotypes observed in each ethnic population were subjected to a variety of statistical analyses. Coefficient of contingency and Cramer's V statistic (measures of degree of association) were consistently higher for Caucasian haplotypes than for those of African Americans. Significantly more unique HLA haplotypes were observed among African American families than among Caucasian families. Thus, our data provide evidence for greater HLA linkage disequilibrium in Caucasians than in African Americans. HLA antigen and haplotype polymorphisms are likely, therefore, to be major immunogenetic factors contributing to ethnic differences in renal allograft survival.

As HIV infection and AIDS continue to spread around the world, the need to develop protective HIVvaccinesisurgent. However,themosteffectiveapproachesto betakenremainuncertain. Recently, evidence for protective immunity to HIV infection has been suggested from the observation of cellular and humoral anti-HIV immune responses in HIV-infected individuals who have not developed AIDS after about 10 years (1). While the immune mechanisms that lead to protection from developing AIDS are incompletely understood, recent findings suggest that both cytotoxic (CTL) and helper T (Th) cells mayplay important rolesin anti-HIV protective immunity (2,3). Moreover, HLA genes orgenes linked to or associated with the HLA complex have been suggested to predispose to either rapid progressor (AIDSwithin approximately 3years ofinfection)versusnon-progressor status (noprogression toAIDS after 10 years) (rev in 4). HLA genes present peptides to cytotoxic and helper T cells in a restricted manner; HLA-A, -B, and -C class I alleles generally present immunogenic peptides to CTL and HLA class II alleles present immunogenic peptides to Th cells (rev in 5). These data have given rise to the notion that the nature of the HIV peptides presented by host HLA molecules to CTL and Th cells may determine both the quality and the quantity of host anti-HIV cellular responses. Thus, one approach to design of HIV preventive immunogens that would induce salutary anti-HIV immune responses would be to design HLA-based HIV vaccines following analysis of the HLA alleles present in the cohort to be immunized andanalysisofthemostcommonHIV variantspresent in thegeographiclocationofthecohort (6). This articlediscusses some of the HLA-related issues relevant to the design ofHLA-based HIV vaccine, and suggests ananalytic approach thatmight betakenif suitable HLA andHIV data baseswereestablished. The human major histocompatibility complex (MHC), of which the HLA class I and class II genes are part, is characterized by the presence of several multigene families, extensive polymorphism at many loci, and significant linkage disequilibrium between alleles at particular loci. The extent of geneticpolymorphism isstillbeing determined but currentlyat least 59,126, and 36differentalleles are known for HLA - A, -B, and -C loci, respectively (7). Similarly, 135, 25, and 65 different alleles have been recognized for the respective HLA class II genes, HLA-DRB1, -DQB1, and -DPB1 (8). In most populations, a few alleles are frequent (gene frequency >10%) but most occur at low frequency (less than10%)and anumber ofthe latter maybe rare (genefrequency <1%). Asis the casefor othergenetic polymorphisms, the frequency of HLA alleles differs among populations. An allele that is common in one population may be rare in another. Some alleles are limited to particular ethnic populations, while others are widely shared among ethnically distinct populations.

The HLA‐A10 crossreacting group consists of the A25, A26, A34, A43 and A66 antigens. Here, we report allelic sequences for A43 and for 2 subtypes of both A26 and A34. Combining these results with previously determined sequences for A25, A26 and A66 enables molecular comparison of all the serologically defined A10 antigens. They form a closely related and well‐defined group of alleles which may have originated with A*2601. Patterns of serological crossreactivity are correlated with sequence and a public epitope shared by A33 and members of the A10 family is localized to residues R62 and N63. The A*2501, A*4301 and A*6601 alleles appear to have derived from A*2601 by single gene conversion events with other HLA‐A alleles. In the case of A*4301, the donor allele was probably an A29 allele as A*4301 has a small element of sequence in the α1helix (residues L62 and Q63) uniquely shared with A29. The chimaeric structure of A43 explains the reactivity of A43 molecules with both A10 and A29 alloantisera. The rare Oriental variant of A26 (A26v*) is encoded by an allele (A*2602) that differs from A*2601 by a unique nucleotide substitution which changes aspartate to asparagine at position 116 in the floor of the peptide binding groove. Thus A*2602 is a functionally distinct allele that originated by a point mutation. Alleles encoding A34 and A66 antigens are found to have very similar structures, explaining the difficulty in their serological definition. Further illustration of serological difficulties in discriminating the antigens of the A10 group is the finding that the A26.2 electrophoretic variant of A26 is identical in structure to A*6601.

From May 1992 to March 1993, 50 infants with severe combined immunodeficiency (SCID) were given bone marrow transplants at Duke University Medical Center. None received chemotherapy for conditioning or for graft-versus-host disease (GVHD) prophylaxis. Forty-one received haploidentical parental marrow depleted of T cells by soybean lectin and sheep red blood cell resetting, and nine received HLA-identical marrow. Forty (80%) survived from 1 week to almost 11 years posttransplantation, including nine of nine (100%) HLA-identical marrow recipients and 31 of 41 haploidentical recipients. T-cell function was present within 2 weeks after transplantation of unfractionated HLA-identical marrow, but not until 3 to 4 months after T-cell-depleted haploidentical marrow stem cells. All 37 patients who are more than 4 months posttransplantation have good T-cell function, and all but one have 100% donor T cells. B-cell function developed slowly or not at all in some recipients of haploidentical marrow. Fourteen (four HLA-identical and 10 haploidentical recipients) have some donor B cells; 19 patients are receiving intravenous immune globulin (IVIG) therapy.

A simple, sensitive ELISA that is performed in 96-well microtiter plates and that requires less than 90 minutes to complete was developed for HLA-DRB oligotyping. The second exon of HLA-DRB1 was amplified using an unlabeled forward primer and a biotinylated reverse primer and the PCR product was immobilized in avidin-coated wells. Subsequent treatment included exposure to 0.4 N NaOH to remove the nonbiotinylated sense strand, addition of a fluorescein-labeled oligonucleotide probe, one or more 5-minute stringency washes, addition of an alkaline-phosphatase-labeled anti-FL FAB, and then alkaline-phosphatase substrate and amplifier. An intense red-violet color developed within 15 minutes in positive wells and could be quantitated by OD readings at 490–495 nm. To control for stringency and to establish threshold OD values for positive reactions, biotin-labeled antisense oligos that were complementary to the probe or that differed by one or more bases were immobilized in wells in place of PCR products. The assay was sensitive to τ0.05 pmol (∼4 ng)/ well and required only standard incubators and waterbaths and an optional microplate reader. All reagents were commercially available. The method should facilitate oligotyping of both class I and class II alleles and is adaptable for analysis of other polymorphic gene products.

HLA haplotypes containing the HLA-B46 allele react with both anti-Cw1 and anti-Cw3 alloantisera, a pattern of reactivity defined as the Cw11 antigen and postulated to involve either a distinctive Cw11 allele or a duplicated HLA-C locus. From serological characterization of CIR cells transfected with B46 cDNA we now demonstrate that the anti-Cw3 reactivity with these haplotypes is solely due to the B46 molecule and not to an HLA-C molecule. Furthermore, isolation and characterization of HLA-C mRNA from cells expressing B46 strongly suggest that anti-Cw1 reactions are directed against the product of a conventional Cw1 allele. The antigenic cross-reactivities of B46 with B62 and Cw3 correlate with its chimaeric primary structure, which is identical to that of B62, except in the alpha 1 helix where it is identical to both Cw3 and Cw1. The structure, distribution and genetic linkage of B46 indicate it is of recent, Asian origin and is the result of a gene conversion, involving Cw1 as the donor gene and B62 as the recipient. These results demonstrate that the Cw11 antigen neither corresponds to a novel HLA-C allele nor a duplicated HLA-C locus, but to a combination of epitopes contributed by linked Cw1 and B46 alleles. The nucleotide sequence we previously and erroneously attributed to a distinct Cw11 allele is now demonstrated to encode Cw8. Isolation of the cDNA clone with this sequence from a library made from a cell homozygous for the B46 haplotype was probably an artefact of contamination.

Alleles encoding five HLA-A and B Ag characteristic of black populations have been isolated and their nucleotide sequences determined. In each case, the "black" allele is similar to a "related" allele found in caucasoid populations. The primary differences between these pairs of alleles are localized clusters of nucleotide substitutions that change two to five residues of the Ag recognition site. The pattern of differences indicates that the pairs of black and caucasoid alleles diverged primarily as a result of interallelic conversion events.