Human leucocytic antigens (HLA) in breast cancer

HLA frequencies of fifty (50) female breast cancer patients were compared with 200 age matched female controls. A total of 20 HLA-A locus, 35 HLA-B locus and 8 HLA-C locus antigens were studied. The HLA-A2, A11, Aw19 and A30; HLA-B8, B14 and HLA Cw6 were found significantly higher than the controls. The HLA-A11, HLA-Aw19 and HLA-B8 were found protective whereas, HLA-A2, HLA-B14 and HLA-Cw6 were a risk for breast cancer. The prective antigens' probable involvement through immunogenic mechanism in breast cancer is emphasized in this article.     

Synthesis and antiviral activity of 7-O-(omega-substituted)-alkyl-3-O-methylquercetin derivatives

In a recent study, we observed a discrepancy rate of 8.5% between the results of molecular and serological HLA class I typing in Caucasian kidney donors and recipients. In the present study we addressed the question how often black individuals are mistyped using the serological technique. 421 Blacks whose HLA typing results were reported to the Collaborative Transplant Study (CTS) were typed retrospectively for HLA-A and -B using a PCR-SSP method. 78 of the 421 individuals (18.5%) showed a discrepancy for HLA-A and 107 individuals (25.4%) for HLA-B. 36.3% of all individuals tested showed either an HLA-A or an HLA-B discrepancy. 13.1% of the discrepancies at the HLA-A locus were due to antigen misassignments and 4.8% were due to missed antigens. HLA-B discrepancies were caused in 15.7% by antigen misassignments and in 10.5% by missed antigens. These results demonstrate an impressive advantage of the PCR-SSP method for HLA-A and HLA-B locus typing over serological typing in black individuals. The high typing discrepancy rate observed in Blacks provides a strong argument for replacing serological typing by the DNA method. It is likely that this will improve the HLA matching correlation in clinical transplantation in Blacks.     

Effect of matching of class I HLA alleles on clinical outcome after transplantation of hematopoietic stem cells from an unrelated donor. Japan Marrow Donor Program

BACKGROUND: The requirements with respect to HLA compatibility and the relative importance of matching for individual class I and class II HLA alleles in the transplantation of hematopoietic stem cells from unrelated donors have not yet been established. METHODS: We performed retrospective DNA typing of alleles at 11 polymorphic loci of HLA genes in 440 recipients of hematopoietic stem cells from unrelated donors who were serologically identical with their respective recipients for HLA-A, B, and DR antigens. Of these recipients, 80 percent had leukemia; the rest had lymphoma, marrow failure, or a congenital disorder. RESULTS: Multivariate analysis showed that incompatibility for HLA-A alleles and incompatibility for HLA-C alleles were independent risk factors for severe acute graft-versus-host disease (GVHD) (HLA-A, P=0.006; HLA-C, P=0.001). Mismatching of HLA-A, but not of HLA-C, alleles was an independent risk factor for death (P<0.001). Matching [corrected] of HLA-C alleles was a significant risk factor for relapse of leukemia (P=0.035). HLA-B disparity was a significant risk factor for both GVHD and death in the univariate analysis, but not in multivariate analysis. Disparities in class II HLA alleles of the DRB1, DQA1, DQB1, DPA1, and DPB1 loci were not identified as significant risk factors for acute GVHD or death in the multivariate analysis. CONCLUSIONS: Genomic typing of class I HLA alleles adds substantially to the success of transplantation of hematopoietic stem cells from unrelated donors, even if the donors are serologically identical to their recipients with respect to HLA-A, B, and DR antigens.     

Current aspects of neurocysticercosis. Clinical and pathological report on 3 cases

The genetics of the serological defined SD antigens of the HLA system, which are governed by three closely linked loci (HLA-A, HLA-B and HLA-C) situated on the chromosome C6, are described. Regarding patermity testing, only the antigens coded by the loci HLA-A and HLA-B are used routinely up to now. Because of the strong linkage disequilibrium between these two loci, they cannot be considered as independent. The influence of the linkage disequilibrium on the calculation of the chance of paternity exclusion and of the plausibility of paternity is discussed and demonstrated in several examples.     

Reactivity of twenty-two cytotoxic human monoclonal HLA antibodies towards soluble HLA class I in an enzyme-linked immunosorbent assay (PRA-STAT)

An ELISA, PRA-STAT was recently introduced for the detection of HLA class I specific antibodies of IgG isotype in patients' sera. We studied the antigenicity of the soluble HLA (sHLA) preparations that are used in this ELISA as the detection matrix, with the aid of a panel of complement binding human HLA monoclonal antibodies (HuMAbs). A total of 22 HuMAbs, including both IgG and IgM were used. CDC and PRA-STAT ELISA were in complete agreement on 9 of the mAbs tested, with 16 HLA-A and 16 HLA-B locus antigens or their splits identified identically on CDC and PRA-STAT. In 7 of the remaining 13 HuMAbs, there was a difference of one antigen in the specificity pattern of the two techniques three times a specificity call not made by CDC, and four times a call not made by PRA-STAT. For the remaining 6 HuMAbs the differences involve 2 antigens (4 HuMAbs), and 3 or 4 antigens (1 HuMAb each). This study shows the validity of PRA-STAT for detection of HLA-class I antibodies, irrespective of isotype, in serum. The immunological integrity of the sHLA preparations used in PRA-STAT is also confirmed, albeit with some slight discrepancies in antibody specificity seen between PRA-STAT and CDC.     

Distribution of HLA antigens in idiopathic pulmonary fibrosis

Divergent observations suggest that genetic factors contribute to the susceptibility to or clinical course of idiopathic pulmonary fibrosis. To determine whether there is an association between the major histocompatibility (HLA) system and idiopathic pulmonary fibrosis, the distribution of 35 antigens of HLA loci A and B was determined among 33 white patients with idiopathic pulmonary fibrosis and 329 healthy white control subjects. Although certain antigens tended to be more prevalent among patients with idiopathic pulmonary fibrosis compared with control subjects, there were no significant differences in the phenotype frequencies of the HLA-A and HLA-B antigens between these 2 groups. Thus, although subtle associations may exist between the HLA loci and idiopathic pulmonary fibrosis, these results indicate that antigens of the HLA-A and HLA-B loci are not linked with major risk factors in this disease.     

Linkage relationships of the loci of the major histocompatibility complex in families with a recombination in the HLA region

A number of families with an established recombination in the major histocompatibility complex has been investigated for markers known to be coded by genes of this linkage group. The results provide further data on the relative position of the loci for HLA-A, HLA-B, HLA-C, HLA-D, Bf, Chido, Rodgers and PGM3 on chromosome 6. A positive lodscore for linkage between HLA and blood group P was found; lodscores between HLA and nineteen other markers were negative.     

HLA association and occurrence of autoantibodies in Asian-Indian patients with ulcerative colitis

OBJECTIVES: The purpose of the present study was to determine the profile of HLA class I antigens, antinuclear antibodies (ANA), and antineutrophil cytoplasmic antibodies (ANCA) in ulcerative colitis (UC) patients from Northern India. METHODS: The study consisted of 100 UC patients with or without extraintestinal manifestations. Data on HLA, ANA, and ANCA were analyzed with respect to age at onset, sex, duration of disease, and occurrence of extraintestinal manifestations, and data were correlated with those of healthy controls from the same population. RESULTS: The most common extraintestinal manifestations in order of occurrence were arthralgia (53.8%), ocular lesions (18%), sacroiliitis (12.7%), hepatobiliary (7.7%), cutaneous (5%), and vascular (2.6%). ANA and ANCA were positive in only 3% of cases. Of the HLA class I antigens, HLA-A19 was significantly increased in UC patients compared with controls (63.4% vs. 33.5%, p < 0.001, RR = 3.4), particularly its subtype HLA-A33 (20.7% vs. 4%, p < 0.001, RR = 6.3). There was no deviation in the frequency of HLA-B locus antigens, whereas HLA-Cw6 was increased significantly in patients compared with controls (14.6% vs. 3.5%, p < 0.001, RR = 4.4). CONCLUSIONS: The occurrence of extraintestinal manifestations in Indian patients with UC is similar to that reported elsewhere, although ANA and ANCA positivity is lower. HLA studies revealed that A19(33) and Cw6 are associated with UC.     

Selection, convergence, and intragenic recombination in HLA diversity

To account for high degrees of human leukocyte antigen (HLA) diversity, a method is proposed for detecting intragenic recombination or gene conversion separately from parallel substitutions or convergent evolution. An application of the method to HLA protein sequences suggests that intragenic recombination played important roles in HLA-B and DPB1, some in HLA-A and DRB1, and least in HLA-C and DQB1 diversity. However, the extent of diversity of these molecules does not necessarily correlate with the frequency of intragenic recombination, supporting the view that (balancing) selection is a primary agent of HLA diversity and often leads to convergent evolution. Computer simulation is carried out to examine two models of balancing selection under the coupled effect with mutation, intragenic recombination, and random drift in a diploid population. It is emphasized that break points by intragenic recombination need be specified to account for HLA diversity. Implications of HLA diversity in human evolution are briefly discussed.     

Sequence-based typing provides a new look at HLA-C diversity

Although extensive HLA-A and HLA-B polymorphism is evident, the true diversity of HLA-C has remained hidden due to poor resolution of HLA-C Ags. To better understand the polymorphic nature of HLA-C molecules, 1823 samples from the National Marrow Donor Program research repository in North America have been typed by DNA sequencing and interpreted in terms of HLA-C diversification. Results show that HLA-Cw*0701 was the most common allele with a frequency of 16%, whereas 28% of the alleles typed as Cw12-18 (serologic blanks). The frequency of homozygotes was 9.8% as compared with previous studies of 18% for sequence-specific primers and 50% for serology. Most startling was the frequency at which new alleles were detected; 19 new HLA-C alleles were detected, representing a rate of approximately 1 in 100 samples typed. These new HLA-C alleles result from 29 nucleotide substitutions of which 4 are silent, such that coding substitutions concentrated about the Ag-binding groove predominate. Polymorphism at the HLA-C locus therefore resembles that at the HLA-A and HLA-B loci more than previously believed, indicating that antigenic stress is driving HLA-C evolution. However, sequence conservation in the alpha-helix of the first domain and a clustering of unique amino acids around the B pocket indicate that HLA-C alleles respond to antigenic pressures differently than HLA-A and HLA-B. Finally, because the samples characterized were predominantly from Caucasians, we hypothesize that HLA-C polymorphism will equal or exceed that of the HLA-A and -B loci as DNA sequence-based typing is extended to include more non-Caucasian individuals.     

HLA photoaffinity labeling reveals overlapping binding of homologous melanoma-associated gene peptides by HLA-A1, HLA-A29, and HLA-B44

Melanoma-associated genes (MAGEs) encode tumor-specific antigens that can be recognized by CD8+ cytotoxic T lymphocytes. To investigate the interaction of the HLA-A1-restricted MAGE-1 peptide 161-169 (EADPT-GHSY) with HLA class I molecules, photoreactive derivatives were prepared by single amino acid substitution with N beta-[iodo-4-azidosalicyloyl]-L-2,3-diaminopropionic acid. These derivatives were tested for their ability to bind to, and to photoaffinity-label, HLA-A1 on C1R.A1 cells. Only the derivatives containing the photoreactive amino acid in position 1 or 7 fulfilled both criteria. Testing the former derivative on 14 lymphoid cell lines expressing over 44 different HLA class I molecules indicated that it efficiently photoaffinity-labeled not only HLA-A1, but possibility also HLA-A29 and HLA-B44. MAGE peptide binding by HLA-A29 and HLA-B44 was confirmed by photoaffinity labeling with photoreactive MAGE-3 peptide derivatives on C1R.A29 and C1R.B44 cells, respectively. The different photoaffinity labeling systems were used to access the ability of the homologous peptides derived from MAGE-1, -2, -3, -4a, -4b, -6, and -12 to bind to HLA-A1, HLA-A29, and HLA-B44. All but the MAGE-2 and MAGE-12 nonapeptides efficiently inhibited photoaffinity labeling of HLA-A1, which is in agreement with the known HLA-A1 peptide-binding motif (acidic residue in P3 and C-terminal tyrosine). In contrast, photoaffinity labeling of HLA-A29 was efficiently inhibited by these as well as by the MAGE-3 and MAGE-6 nonapeptides. Finally, the HLA-B44 photoaffinity labeling, unlike the HLA-A1 and HLA-A29 labeling, was inhibited more efficiently by the corresponding MAGE decapeptides, which is consistent with the reported HLA-B44 peptide-binding motif (glutamic acid in P2, and C-terminal tyrosine or phenylalanine). The overlapping binding of homologous MAGE peptides by HLA-A1, A29, and B44 is based on different binding principles and may have implications for immunotherapy of MAGE-positive tumors.     

The distribution of HLA in a Polynesian population-Western Samoans

HLA and gene frequencies are presented for a Polynesian population-the Western Samoans. Within the HLA-A locus A2, A9 and A11 have the highest frequencies and account for 55% of the alleles in this locus. The alleles BW22 and BW40 had the highest frequencies in the HLA-B locus and accounted for 51% of the alleles. The blank gene frequencies for the HLA-A and B loci are .382 and .373 respectively. Significant linkage disequilibrium was found with the haplotypes A1,B7; A3,B7;A2, BW40; A9, BW40 A9, BW22. The most frequent haplotype was A2,BW40. Comparatively low values within this population and between this and other Polynesian populations are discussed in terms of selection, migration and drift.     

High resolution HLA-C typing by PCR-SSP: identification of allelic frequencies and linkage disequilibria in 604 unrelated random UK Caucasoids and a comparison with serology

Recent evidence indicates that HLA-C molecules are biologically relevant by eliciting T-cell responses and exerting control over NK cell function. In addition, HLA-C is associated with susceptibility to various diseases, notably psoriasis vulgaris. Clarification of the full biological roles for HLA-C has however proved difficult because detection of HLA-C antigens by complement mediated cytotoxicity using alloantisera is inefficient. Up to 50% of individuals in every race have serologically undetectable HLA-C locus antigens due to a combination of relatively low expression, lack of serological reagents and a lack of information about the distribution of the HLA-C blank alleles. Recently, amplification of DNA using sequence-specific primers (PCR-SSP) has proved a reliable, accurate and rapid method for medium resolution HLA-C typing. We have now developed high resolution HLA-C typing by PCR-SSP utilizing allele and group-specific PCR-SSP reactions which can identify all HLA-C alleles (except non-coding change alleles) in most heterozygous combinations. Using this system we have typed 604 unrelated United Kingdom Caucasoids to generate accurate frequency and linkage disequilibrium data. To assess the validity of serology for HLA-C, PCR-SSP typings for 527 out of the 604 individuals were compared to serology. We find that the frequency of many HLA-C antigens has been underestimated by serology and some antigens such as Cw6 are consistently assigned incorrectly by serology. The overall discrepancy rate between serology and SSP was high at 37% (195/527). High-resolution HLA-C typing of 112 International Histocompatibility Workshop cell lines has also been performed.     

Localization of the hemochromatosis gene close to D6S105

The hemochromatosis (HC) gene is known to be linked to HLA-A (6p21.3); however, its precise location has been difficult to determine because of a lack of additional highly polymorphic markers for this region. The recent identification of short tandem repeat sequences (microsatellites) has now provided this area with a number of markers with similar polymorphic index to the HLA serological polymorphisms. Using four microsatellites--D6S105, D6S109, D6S89, and F13A--together with the HLA class I loci HLA-A and HLA-B in 13 large pedigrees clearly segregating for HC, we have been able to refine the location of the HC gene. We identified no recombination between HC and HLA-A or D6S105, and two-point analyses placed the HC gene within one centimorgan (cM) of HLA-A and D6S105 (HLA-A maximum of the lod score [Zmax] of 9.90 at recombination fraction [theta] of 0.0, and D6S105 Zmax of 8.26 at theta of 0.0). The markers HLA-B, D6S109, D6S89, and F13A were separated from the HC locus by recombination, defining the centromeric and telomeric limits for the HC gene as HLA-B and D6S109, respectively. A multipoint map constructed using HLA-B, HLA-A, and D6S109 indicates that the HC gene is located in a region less than 1 cM proximal to HLA-A and less than 1 cM telomeric of HLA-A. These pedigree data indicate an association between HC and specific alleles at HLA-A and D6S105 (i.e., HLA-A3 and D6S105 allele 8).(ABSTRACT TRUNCATED AT 250 WORDS)     

Human leukocyte antigen class I expression. Marker of poor prognosis in uveal melanoma

PURPOSE: Because the expression of human leukocyte antigen (HLA) antigens is important for immunologic recognition of tumor cells, we determined expression of locus-specific HLA class I antigens in uveal melanoma and tested whether the level of HLA expression was related to prognosis or associated with known prognostic parameters. METHODS: Expression of HLA-A and -B antigens was determined on 30 formalin-fixed and paraffin-embedded sections of uveal melanoma by immunohistochemistry with locus-specific monoclonal antibodies and scored semiquantitatively. RESULTS: The level of expression of HLA-A and -B varied between uveal melanomas. Expression levels of HLA-A and -B were significantly correlated (P = 0.02). High HLA-B expression was significantly correlated with the presence of epithelioid cells (P = 0.04) in the tumor. Expression levels of HLA-A as well as of HLA-B, cell type, mitotic rate, Mib-1 score, and largest tumor diameter were significant predictive factors for survival. High expression of HLA-A and -B was associated with a decreased survival. Multiple Cox regression analysis with stepwise selection of covariates showed that the contribution of HLA-A expression to survival (P = 0.0003) exceeded that of tumor diameter (P = 0.02) and Mib-1 score (P = 0.04). CONCLUSIONS: Lack of expression of HLA-A as well as of HLA-B antigens on uveal melanoma is correlated with a better patient survival. Our data suggest that shedding of uveal melanoma micrometastases with a low expression of HLA class I into the systemic circulation may facilitate their removal and prevent the development of metastases. These findings support a protective role for natural killer cells in the development of metastatic disease in uveal melanoma.     

HLA markers and progression in psoriatic arthritis

OBJECTIVE: To investigate whether the addition of all serologically defined HLA antigens to a baseline model further influences the predisposition to disease progression in psoriatic arthritis (PsA). METHODS: Patients with PsA followed prospectively over 19 years were studied. Clinical and laboratory assessments of both active inflammation and clinical damage were performed at 6 month intervals according to a standard protocol. Progression of damage was defined as transition to higher damage states defined by the number of damaged joints. A model that provides estimates of the ratio of transition rates for an individual with the antigen versus one without, and examines the antigen effect on each of the 3 transition rates, was used. HLA antigens were examined in groups by loci under the assumption of common effects across transitions when added to the basic model. The significance levels were examined in comparison with Bonferroni type corrections. Likelihood ratio chi-squared statistics were used as a basis for the significance levels. In total, 292 patients with PsA were included in the study. RESULTS: Only HLA-B22 was added to the original model, which includes HLA-B39, providing risk for progression in early stages, HLA-B27 in the presence of HLA-DR7 providing risk for progression through all states, and DQw3 providing increased risk in the absence of DR7, while in the presence of DR7 it provides "protection." HLA-B22 provides protection from disease progression through all states. CONCLUSION: This study extends our report that HLA antigens serve as markers for disease progression in PsA.     

Contribution of HLA genes to genetic predisposition in diffuse panbronchiolitis

Diffuse panbronchiolitis (DPB) in East Asia is a distinctive chronic obstructive pulmonary disease of unknown etiology. We hypothesize that the disease susceptibility is due to genetic predisposition unique to Asians. Association between human leukocyte antigen (HLA)-Bw54 and the disease was previously reported. In the present study, using newly developed polymerase chain reaction (PCR)- based methods, we directly analyzed HLA class I and II alleles in 76 Japanese patients. HLA-A, -B, and -C antigens were screened by the conventional typing method, and then B22-group alleles including HLA-B54 were genotyped by single-strand conformation polymorphism analysis. Alleles of HLA-DRB1 gene were fully determined by the microtiter plate hybridization method. Thirty-seven percent of the patients possessed HLA-B*5401 allele conserved predominantly in East Asians, as compared with 15% of 110 healthy volunteers (chi2 = 12.4, p = 0.0004). In addition, 4% of the patients possessed B*5504 also unique to Asians but a rare allele which was not found in normal control subjects in this study. Typing of HLA-DRB1 class II gene did not demonstrate strong positive association with the disease. A33, B44, and DRB1*1302 showed negative association with the disease. We conclude that distinctive molecular structure of HLA-B alleles or a closely linked gene in the HLA region contributes to genetic predisposition in diffuse panbronchiolitis. This may partly explain why this disorder is found primarily in Asians.     

Molecular typing shows a high level of HLA class I incompatibility in serologically well matched donor/patient pairs: implications for unrelated bone marrow donor selection

In comparison with HLA-matched sibling bone marrow transplants, unrelated donor transplants are associated with increased graft-versus-host disease and graft failure. This is likely in part due to HLA incompatibilities not identified by current matching strategies. High resolution DNA-based typing methods for HLA class II loci have improved donor selection and treatment outcome in unrelated donor bone marrow transplantation. By using DNA-based typing methods for HLA-A and -B on a cohort of 100 potential bone marrow donor/patient pairs, we find that serological typing for HLA class I is limited in its ability to identify incompatibilities in unrelated pairs. Furthermore, the incompatibilities identified are associated with the presence at high frequency of alloreactive cytotoxic T-lymphocyte precursors. DNA typing also indicates that HLA-C mismatches are common in HLA-A and -B serologically matched pairs. Such mismatches appear to be significantly less immunogenic with respect to cytotoxic T-lymphocyte recognition, but are expected to influence natural killer cell activity. Thus, improved resolution of HLA class I shows many previously undisclosed mismatches that appear to be immunologically functional. Use of high resolution typing methods in routine matching is expected to improve unrelated donor selection and transplant outcome.     

Histocompatibility antigens in multiple sclerosis in children

A phenotyping was done in respect of HLA system in 14 children with documented multiple sclerosis (MS), 20 children with potential MS, and 42 their near relations. HLA-B12 antigen was recordable with high frequency (RR = 6.29; P < 0.025) while HLA-B18 with low one (P < 0.01) as compared to normal subjects both among patients in the general group and in those with proved MS. The latter showed a tendency toward increase in frequency HLA-B7. Children with significant MS where there was an association in the phenotype of HLA-B12 or HLA-B7 with HLA-A3 ran predominantly an aggravating course while their association with HLA-A2 resulted in a more benign course. The results obtained in respect of HLA antigens in MS in children differ from those of other authors on MS in adults.