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Despite growing interest about the impact of donor-specific HLA antibodies (DSA) in LT limited data are available for pediatric recipients. Our aim was to perform a retrospective single-center chart review of children (0-16 years) having undergone LT between January 1, 2005 and December 31, 2017, to characterize DSA, to identify factors associated with the development of de novo DSA, and to analyze potential associations with the diagnosis of TCMR. Information on patient- and donor-characteristics and LB reports were analyzed retrospectively. Serum obtained before LT and at LB was analyzed for presence of recipient HLA antibody using Luminex® technology. MFI > 1000 was considered positive. In 63 pediatric LT recipients with a median follow-up of 72 months, the overall prevalence of de novo DSA was 60.3%. Most were directed against class II antigens (33/38, 86.8%). Preformed DSA were present in 30% of patients. Twenty-eight (28/63) patients (44.4%) presented at least one episode of TCMR, mostly (12/28, 43%) moderate (Banff 6-7). De novo DSA were significantly more frequent in patients with TCMR than in patients without (75% vs 48.6%, P = .03), and patients with preformed and de novo DSA had a significantly higher rate of TCMR than patients without any DSA (66.7% vs 20%, P = .02). Neither preformed DSA nor de novo DSA were associated with frequency or severity of TCMR. Recipients with lower weight at LT developed de novo DSA more frequently (P = .04). De novo DSA were highly prevalent in pediatric LT recipients. Although associated with the development of TCMR, they did not appear to impact the frequency or severity of TCMR or graft survival. Instead, de novo DSA may suggest a state of insufficient IS.

Objectives: Introduction of solid phase assays for HLA antibodies detection led to application of new algorithms for the immunological monitoring of patients in renal transplantation and prevented many cases of hum oral rejection. Methods: In this work, we made a single observation of a comparative study between ELISA and LUMINEX® on 60 patient’s sera prior to start using in routine LUMINEX® at the two compatibility department of Pasteur Institute Casablanca, Morocco. Data were analyzed following manufacturer recommendations. Finding: Concordance rates between the results for individual HLA Class I and Class II antigens measured by both techniques were found to be 73, 3%. Whereas discrepancies were around 25%. The use of sensitive and specific techniques in transplantation is an important parameter which could improve this field. Improvement: Following this study, significant difference between the tests was found, however LUMINEX detect HLA antibodies with higher sensitivity, which can provide additional information for the graft outcome. Keywords: Anti-HLA Antibodies, Kidney Transplantation, ELISA, LUMINEX

This article presents information about the distribution of antigens of the second class in patients with papulo-pustular and nodulous forms of acne. Class II antigens distribution was estimated as the total Group and groups of patients allocated depending on the severity of the clinical picture. Association revealed the presence of severe acne with antigens of histocompatibility of HLA-complex that confirms the importance of immunogenetic factors in the pathogenesis of this condition.

HLA matching is conventionally assessed by counting the number of MisMatches (MM) in the class I antigens and class II antigens of the donor and recipient. There is an overlap of matching scores in the MM scoring method. A numerical method has already been developed to quantify the degree of HLA matching in Low Resolution HLA matching. This study has been done to formulate an algorithm for High resolution HLA matching, with a parameter named as HLA Matching (HM) score. Mathematically, 4096 discrete values of HM score existing between 0 and 1 are obtained in 3 loci comparison for renal transplantation. Each value of HM score is unique for every possible matching combination. Donor with the highest percent HM score is considered as the best HLA matched donor. This method overcomes all the disadvantages of the conventional MM scoring method. This algorithm is useful in the donor or recipient selection and the graft survival studies.

BACKGROUND Development of de novo donor-specific antibodies (dnDSA) has detrimental effects on graft survival in several types of solid organ transplants. However, limited information exists about the effect of dnDSA on pancreas transplant graft survival. METHODS We report our experience with pancreas recipients transplanted between January 01, 2005, and August 31, 2017. RESULTS We identified 541 pancreas transplant recipients, of which 121 developed dnDSA and 420 did not. Thirty-two percent developed dnDSA against HLA class I antigens, 56% developed against class II antigens, and 12% developed against both. Fifty-two percent of the patients in the dnDSA+ and 24% in the dnDSA- group underwent pancreas biopsy, mainly due to a rise in pancreatic enzymes. Rejection was found in 42% of the dnDSA+ group, and 20% of the dnDSA- group(P < 0.001). There were 36% uncensored graft failures in the dnDSA+ group and 17% uncensored failures in the dnDSA- group (P < 0.001). A similar trend was seen in death-censored graft failure between the groups. In univariate Cox regression analyses, male sex, older age, and recipients of simultaneous pancreas and kidney transplant were found to be protective for death-censored graft failure; multiple transplants, dnDSA, requirement for pancreas biopsy and presence of pancreas rejection were associated with increased risk of graft failure. In multivariate analysis, only older age and dnDSA were significantly associated with death-censored graft failure. CONCLUSIONS Our findings suggest that dnDSA in pancreas transplant recipients are associated with increased rates of rejection and graft failure. Timely detection of dnDSA through regular screening and early treatment of pancreas rejection may ultimately improve graft outcomes.

Background: HLA typing analysis is important in renal transplant patients. Objectives: We made a plan to determine the most frequent HLA antigens in Iranian kidney transplant patients. Patients and Methods: In a retrospective cross sectional study, HLA patterns were defined in 512 kidney transplant recipients (67% male and 33% female) from different transplant centers of Tehran, Iran between 2008 and 2011 by microcytotoxicity assay. Results: The studies samples were of different ethnic groups of the Iranian kidney transplants. Considerable variations were observed in each HLA sub class. A2, A1, A3, A24 and A26 were the most frequent HLA-A antigens. Among HLA-B, the predominant antigens were B35; B13, B15, B13 and B18. The most frequent HLA-DR antigens were DR 4, DR11, DR1, DR3 and DR15. DQ1 showed the highest frequency and followed by DQ3 and DQ2. Conclusions: These results showed considerable heterogeneity in both HLA class I and class II antigens, which reflects recent admixture of this group with neighboring Middle East populations.

Case history: We evaluated a live donor (D1) and recipient (P1) pair for potential kidney donation however their flow crossmatches (FXM) continuously result in B-cell positive. P1 was tested negative by single antigen beads and no donor specific antibody (DSA) was evident. Patient has been transfused once in 2014 and treated with adalimumab for ankylosing spondylitis in the past. Methods: Autologous FXM of D1 was conducted. A series of FXM with surrogate donors was conducted. Supplemental single antigen beads, FlowPRA beads and Luminex-based mixed screening beads were also conducted but results are questionable. Results: After the first allo FXM, a repeat was done to rule out B cell positive FXM whether it was reproducible. Since patient was screened negative by single antigen beads assay and supplemental beads, absence of DSA could not explain why B cell FXM can be positive. When patient serum subject to two other surrogate donors (D2 “O” and D3 “A”) interestingly B cell FXM has become negative. To rule out blood type issue and non–HLA factors, autologous FXM of D1 and allo-FXM with zero PRA serum (P2 “A”), and with positive PRA serum (absence of DSA, P3 “A”) were performed and all were found negative, but remained positive with diluted serum of P1. Patient P1 was tested again in 3 months however the same result remains. The final FXM was then focused on testing with surrogate donors (D4 and D5) who carry the same class II antigens as D1. The result became positive with D5. Although no clear evidence can confirm the antibody to DR11 to be allele specific, the collective results infer that suspected DSA DR11 is not distinguishable by FlowPRA screening beads and mixed beads and not detectable by single antigen and supplemental beads. Conclusion: This is the first case in our experience to discover such a situation with “cold bead” or specificity-unproven DSA. Transplantation is not recommended. Correlation between different assays and diligent testing to clarify unreasonable positive FXM is very important especially in cases of autoimmune disease.

The HLA class I and class II phenotypes of a panel of 114 unrelated Nigerians have been determined. The panel was tested for all the known class I antigens and comparisons of the HLA-A and -B frequencies with those of other African Negroid populations revealed some differences. Only limited comparisons could be made for the HLA-DR and -D frequencies as these are not available for any well-defined African Negroid population. The data concerning the class II antigens of this panel are the most interesting. Half of the DRw11-positive panel members are DQw3 negative and DQw1 positive. In addition, there is dissociation of some HLA-D and -DR specificities, a number of panel members are positive for an HLA-D specificity and are negative for the corresponding HLA-DR specificity. Our results show the value of population studies in the investigation of the relationship between the different HLA class II antigens.

Fourteen monoclonal antibodies recognizing monomorphic and polymorphic epitopes on class I and class II antigens of the human MHC have been assayed on lymphocytes of a panel of 20-150 BoLA typed bovine animals from 12 different breeds. Some monomorphic antibodies cross-reacted and others did not. Two polymorphic monoclonal antibodies in man recognize a polymorphism in cows that follows allospecificities (BoLA-w3, w9) already described. Immunoprecipitation experiments with monomorphic anti-B2m and anti-HLA-DR monoclonal antibodies have shown that these cross-reactions concern BoLA antigens. They also revealed that Ia-like antigens in cattle present the same two chain features characterized in other species.

Thirty-five wild mice (Mus musculus L.) were captured at four different localities in Chile. The mice were typed for the presence of 15 K-, 11 D-, 14 A-, and two E-region H-2 antigens, using the complement-antibody microcytotoxicity assay. The mice from the sample representing the largest locality had a characteristic antigenic profile distinguishing them from other mouse populations thus far studied. With respect to class I H-2 antigens, the profile was characterized by the presence of antigens H-2K.16, 31, 103, 19, 108, 21, 33, 26, 115, and H-2D.4, 106, 30, 32, 111, 114, and 18 (in order of decreasing antigen frequency), and by the absence of antigens H-2K.15, 17, 20, 113, 116 and H-2D.2, 9, 110, and 112. The profile was, furthermore, characterized by the relatively high frequency of antigens H-2K.16, 31, and H-2D.4 and 106. The profile of class II antigens was also unique to the Chilean population but less conspicuously so than that of the class I antigens. Analysis of antigenic associations suggested that among the 34% blank H-2K alleles there were at least two coding for relatively frequent but as yet unidentified K antigens. Similarly, among the 57% blanks at the H-2D locus there were at least two frequent alleles encoding unidentified D antigens. Analysis of genetic distances suggested similarity between South American mice and mice from coastal regions of Europe.

Sixteen monoclonal antibodies against antigens coded for by the RT1 complex of the rat have been produced. Fourteen are specific for the a haplotype: six recognize class II and eight class I antigens. Two are specific for the 1 haplotype, one reacting with class I and the other with class II antigens. By means of these monoclonal antibodies four independent clusters of antigens for class I antigens of the a haplotype and three for class II antigens could be defined. The three antigenic sites of class II antigens reside on the same heterodimer. The monoclonals described here are characterized with regard to Ig class and subclass, pI, and complement-activating capacity.

Neurocysticercosis, caused by encysted larvae of the tapeworm Taenia solium, is the most common infection of the central nervous system and a major public health problem in many countries. Prevalence in the region of Curitiba, located in the southern Brazilian State of Paraná, is one of the highest in the world. The genetics of host susceptibility to neurocysticercosis (NCC) is still obscure. To investigate if major histocompatibility complex (MHC) genes influence individual susceptibility to NCC, we performed a case-control association analysis. Fifty-two Caucasoid patients and 149 matched controls were typed for antigens of the HLA-A, B, C, DR and DQ loci. All patients had computerized tomography and clinical features compatible with parenchymal NCC. Indirect immunofluorescence of cerebrospinal fluid showed that 19 (37%) of the patients presented anti-cysticercus antibodies at titers ³ 1:10. Frequencies of HLA specificities in the whole group of patients and in the subgroup with antibodies in cerebrospinal fluid were compared to those of the control group. No significant difference was found. These results do not support the hypothesis of HLA gene participation in susceptibility to parenchymal neurocysticercosis.A neurocisticercose, causada pelo cisticerco, a larva do cestóide Taenia solium, é a infecção mais comum do sistema nervoso central e constitui importante problema de saúde pública em muitos países. A sua prevalência na região de Curitiba, localizada no Estado do Paraná, foi estimada em 9%, situando-se entre as mais elevadas do mundo. Os aspectos genéticos de suscetibilidade à neurocisticercose (NCC) ainda são pouco conhecidos. Com o objetivo de investigar se genes do MHC influenciam a suscetibilidade individual à NCC, realizamos uma análise de associação caso-controle. Cinqüenta e dois pacientes caucasóides e 149 indivíduos-controle pareados foram tipados para antígenos dos locos HLA-A, B, C, DR e DQ. Todos os pacientes apresentavam tomografia computadorizada e sinais clínicos compatíveis com NCC parenquimatosa. Imunofluorescência indireta do líquido céfalo-raquidiano mostrou que 19 (37%) pacientes apresentavam anticorpos anti-cisticerco com títulos ³1:10. As freqüências de especificidades HLA no grupo total de pacientes e no subgrupo de pacientes que apresentaram anticorpos no líquor foram comparadas àquelas do grupo controle. Nenhuma diferença significativa foi detectada. Esses resultados não sustentam a hipótese de participação dos genes HLA na suscetibilidade à neurocisticercose parenquimatosa.

Utilizing phage display peptide libraries, we have identified and mapped the antigenic determinants recognized by mouse monoclonal antibodies (mAb) on two sets of immunologically important molecules, HLA class I and class II antigens. Anti-HLA class I mAb TP25.99 recognizes a conformational and a linear determinant on distinct regions of the HLA class I α3 domain. Anti-HLA class I mAb HO-4 recognizes a conformational determinant on the α2 domain of HLA-A2 and A28 allospecificities. Anti-HLA-DR1, -DR4, -DR6, -DR8, -DR9 mAb SM/549 recognizes a conformational determinant on the β chain of HLA class II antigens. These results indicate the versatility of phage display peptide libraries to characterize antigenic determinants recognized by anti-HLA mAb.

The association between cervical neoplasia and certain HLA phenotypes observed in different studies has not been consistent. By serological typing, the association between HLA antigens, cervical carcinoma and cervical intraepithelial neoplasia (CIN) was studied in a group of 172 and 116 patients, respectively. We demonstrated an increased frequency of B63 in patients with HPV types other than HPV 16 or 18, and B55 in patients that were negative for all HPV types. The association between cervical carcinoma and DQ3, described in various populations, was not observed in the present study. However, we confirmed other previously observed associations between cervical cancer and class II antigens, i.e., a positive correlation with DR15 irrespective of the HPV status, with DR3 in patients harboring HPV types other than HPV 16 or 18, and with DR11 among HPV 16 positive patients. In contrast, a negative correlation between DR13 and HPV positive cervical cancer was observed which suggests protection of this antigen against HPV-associated cervical cancer. A slight increase of DR15 and DQ4 antigens was observed in CIN patients, suggesting that these specific HLA antigens may be important in determining the risk of CIN.

The etiology of pemphigus vulgaris is still unknown. Reported familial cases are indicators of a genetic aspect of the disease. We report a brother and sister with simultaneous onset of pemphigus vulgaris. The class II antigens, HLA DRB1*04 and DQB1*03 were detected in both patients. The oral mucosa was affected in one them. Elevation of transaminase levels due to azathioprine therapy was observed in these two cases.

A multiinstitutional study was carried out to evaluate immunologic responses for human recipients of massive frozen (-80 degrees C) osseous and osteochondral allografts. Allografts were used to reconstruct skeletal defects associated with a variety of traumatic degenerative and neoplastic disorders. Serum samples were obtained before surgery and from 1 month to 4 years after surgery. Sera were tested by microcytotoxicity against T cells from 60 donors for human leukocyte antigen Class I antibodies and against beta 2-microglobulin treated B cells from 40 donors for human leukocyte antigen Class II antibodies. Panels were selected to represent the majority of known human leukocyte antigen specificities. Of the 84 cases evaluated, 62 (74%) received blood transfusions and 28 of 44 (64%) female recipients had been previously pregnant. Sensitization before transplant was shown in 33 of 84 (39%) patients. After grafting, 49 of 84 (58%) recipients showed evidence of sensitization to Class I antigens and 46 of 84 (55%) recipients showed evidence to sensitization to Class II antigens. Overall sensitization was 67%.

We investigated serological human leukocyte antigen (HLA) types in patients with histories of Miller Fisher syndrome (MFS) and Guillain-Barré syndrome (GBS) with ophthalmoplegia, in whom serum anti-GQ1b IgG antibody was present during the acute phase. We examined class I antigens (A, B and C) in 32 patients and class II antigens (DR and DQ) in 30, but found no association. We conclude that particular serologically defined HLA types are not preferred for the immunoresponse of anti-GQ1b IgG antibody in MFS and GBS.

The presence of HLA-homozygous typed cell (HTC) in transfused blood cells possibly induces transfusion-associated graft versus host disease (GVHD) which usually causes immediate death for transfusion-associated GVDH in a Japanese population, the frequency of HTC was investigated by serological typing for class I antigens and by DNA typing for class II antigens. Out of 3, 000 Japanese cells randomly collected, cells from 32 Japanese (1.1%) were found to be HLA-homozygous for the HLA-A, -B, -C, DRB1, DQA1 and DQB1 genes. This high frequency suggests that removal or inactivation of leukocytes in donors' blood is necessary to prevent transfusion-associated GVHD.

Objective: The aims of the present study were to typify the human leukocyte antigen system (HLA)-A, B (class I) and HLA-DR, DQ (class II) antigens and to assess the frequency of the presence of these antigens in the Turkish population with recurrent aphthous ulceration (RAU) and Behçet's disease (BD) compared to healthy subjects. Subjects and Methods: Thirty patients with RAU, 30 with BD, and 15 healthy subjects were included in the study. HLA typing was performed by serology with commercial kits for HLA class I and II (One Lambda, Canoga Park, Calif., USA). Results: The HLA-A23 frequency was 26.7% in the RAU patients, which was significantly higher than the 3.3% frequency in the patients with BD (p < 0.05). The HLA-A24 frequency was 33.3% in the RAU patient group, which was significantly higher (p < 0.05) than the frequency in the healthy subjects (6.7%). Significantly higher frequencies (46.7%) of HLA-A30 were found in the healthy subjects compared to the BD (13.3%) and RAU (3.3%) patients (p < 0.05 and p < 0.01, respectively). A higher frequency of HLA-B13 was observed in the RAU (23.3%) patients compared to the BD (0%) patients (p < 0.01). A decrease was observed in HLA-DR10 and HLA-DR17 in the RAU patients (p < 0.05), while a higher frequency of HLA-DR10 was observed in the BD patients compared to the RAU patients (p < 0.01). Conclusions: These results showed that RAU and BD were not in the same spectrum and the involvement of other genetic and/or environmental factors might be responsible for the development of these diseases and/or disease progression.

Summary Pediatric adrenocortical tumors are neoplasms that only rarely occur in pediatric patients. Their clinical behavior is often unpredictable, and the histologic criteria of malignancy used in adults are not always useful in children. The aim of this study was to validate the prognostic value of the pathologic criteria of Wieneke et al and to evaluate the potential prognostic expression of matrix metalloproteinase 2 and human leucocyte-associated antigen (HLA) class II antigens in a series of 20 pediatric patients affected by adrenocortical tumors, who were enrolled in the Italian Pediatric Rare Tumor (TREP) Study between 2000 and 2007. The age range was 0 to 17.5 years (mean, 7.28 years) with a male-female ratio of 1:2. The mean follow-up was 64.4 months. The histologic diagnoses were reviewed, and the cases were classified using the criteria for malignancy proposed by Wieneke et al. The immunohistochemical expression of matrix metalloproteinase 2 and HLA class II antigens was scored by semiquantitative analysis and compared with the clinicopathologic parameters and outcome. Based on the scoring system of Wieneke et al, 7 tumors were classified as malignant; 12 tumors, as benign; and only 1 tumor, with “unpredictable behavior.” In all cases, the clinical behavior was consistent with the pathologic criteria of Wieneke et al. Notably, areas of regressive myxoid changes, not included among the criteria of Wieneke et al, were observed in all but 1 case of malignant tumors and only in 2 cases of benign tumors. Matrix metalloproteinase 2 was focally to diffusely expressed in all malignant and in most benign tumors. HLA class II antigens immunoreactivity was absent in all benign tumors and restricted to rare isolated cells in most malignant tumors. Our findings confirm that the pathologic scoring system of Wieneke et al is a simple and reproducible diagnostic tool to predict prognosis in pediatric adrenocortical tumors. Unlike in their adult counterpart, the expression of matrix metalloproteinase 2 or the loss of HLA class II antigens does not discriminate between benign and malignant tumors in children. Although pediatric adrenocortical tumors seem to be similar histologically to their adult counterparts, it is likely that they have distinctive molecular features.

We examined the proliferative response of T lymphocytes from thirty-eight patients with Graves' disease (17 untreated thyrotoxic and 30 euthyroid on antithyroid medication) to phytohemagglutinin, anti-CD3 MoAb and phorbol esters, as well as the capacities of these lymphocytes to produce interleukin 2 and the density of interleukin 2 receptors and major histocompatibility class II antigens. We found that the response of T lymphocytes to phytohemagglutinin, anti-CD3 monoclonal antibody and phorbol esters from untreated thyrotoxic Graves' disease was significantly enhanced as compared to treated patients and normal controls. Interleukin 2 production by mitogen-triggered T lymphocytes in both treated and untreated patients with Graves' disease was comparable to that of the control population. Interleukin 2 receptor density was found to be normal, whereas that of human leukocyte antigen-DR was increased in both untreated and treated patients. Following lymphocyte stimulation, there was an increase in human leukocyte antigen-DR and interleukin 2 receptor expression in patients with untreated Graves' disease. Significant correlations were found between thyroid hormone concentration and the proliferative responses to the polyclonal mitogen phytohemagglutinin, anti-CD3 monoclonal antibody and phorbol esters in untreated Graves' patients. Furthermore, during the follow-up of 9 patients, attainment of normal thyroid function after antithyroid treatment was associated with a decrease in and normalization of T-proliferative responses. Our data reveal that active Graves' disease is associated with T cell activation and this is probably related to immunological dysregulation as well as to hyperthyroxinemia.

SUMMARY The distribution of CLA class I and II antigens in CAE virus-infected, diseased and healthy Saanen goats has been investigated. Three class I antigens and two class II antigens showed a statistically different frequency in the two groups.

Class I and II HLA typing was investigated before and at various intervals after a 10 Gy total body irradiation delivered over 4 h, prior to allogeneic bone marrow graft for various hematological malignancies, in 14 patients. A reliable class I HLA typing appeared to be possible in almost all cases 6-8 hours after the start of irradiation but was only possible in 5 patients after 24 h. Preliminary results with class II antigens might suggest a more marked "fragility" of this antigen class after irradiation. These results encourage the drawing of blood samples for HLA grouping as soon as possible after accidental whole-body irradiation.

Advanced microsurgical techniques have allowed performing different composite tissue allotransplantations (CTA), although immunology and pharmacotherapy still have many unresolved questions. Different CTA models were developed to explore and answer these questions during the past 25 years. Most experimental transplants to date have been performed in rats, and the immune system of the rats has fundamental differences from that of the humans, such as the lack of expression of class II antigens on the endothelial cells.7 Over the past 20 years, we have developed 17 CTA models of the rat in our laboratory in an effort to characterize differences in the mechanism of graft acceptance and rejection. These CTA models were tested to (1) determine the mechanism of CTA acceptance and rejection; (2) determine the immunologic pattern of responses of different tissue types in CTA; (3) evaluate the immunologic response of transplant grafts of different dimensions and skin components of the most antigenic of CTA tissues10; (4) test the effects of vascularized bone marrow transplantation (VBMT) on immunotolerance; (5) develop new immunosuppressive and immunomodulatory treatment protocols; and (6) correlate histological, morphological, and functional responses of CTA with different immunosuppression protocols. We overwrite CTA models according to the following classification: vascularized bone marrow transplant models, vascularized skin allograft models, composite allograft transplantation models, and other models (Tables 51.1 and 51.2).

We compared the distribution of HLA-ABC (Class I) and HLA-DR, -DQ, and -DP (Class II) antigens in fresh, non-lyophilized human cornea with that of rehydrated lyophilized epikeratoplasty lenticules. Class I antigens were detected at similar levels in both the control corneas and the epikeratophakia lenticules. Class II antigens, which were limited to cells at the limbus of control corneas, were absent from the epikeratophakia lenticules. Although epikeratophakia lenticules are not necessarily immunogenic, these results clearly demonstrate that they are antigenic and express selected major histocompatibility antigens. In the context of these findings, we discuss the lack of reports of immunologic rejection following epikeratoplasty.

HORIE, Y., CHIBA, M., IIZUKA, M. and MASAMUNE, O. Class II (HLA-DR, HLA-DP, and HLA-DQ) Antigens on Colonic Epithelia in Ulcerative Colitis: A Comparison between Uneventful and Intractable Cases. Tohoku J. Exp. Med., 1991, 165 (2), 87-97-Class II antigens on colonic epithelia involved in ulcerative colitis (UC) with uneventful or intractable courses were investigated using an immunoperoxidase method. Twenty normal colonic mucosa served as normal controls. Nineteen specimens from 14 uneventful cases and 23 specimens from 12 intractable cases were studied. Normal colonic epithelia did not express class II antigens. In UC, there were no differences between uneventful cases and intractable cases in the frequencies of class II antigen expression, the distribution of class II antigen expression ratio, or the mutual relationship of the extent of expression of the three class II antigens on colonic epithelia. However, while the extent of expression of HLA-DR and HLA-DP antigens on the epithelia was positively correlated with the degree of inflammation in uneventful cases, there was no such correlation in intractable cases. These observations may suggest that the induction mechanisms of class II antigens on colonic epithelia in UC differ in uneventful and intractable cases.

Objective: The association of the major histocompatibility complex (MHC) with psoriasis vulgaris has been reported in different ethnic groups. However, an identification of human leukocyte antigen (HLA) genes that determine susceptibility to the disease has not been reported previously among the Arabs of the Arabian Peninsula. This study was conducted with the objective of establishing any correlation between psoriasis and the expression of HLA class I and class II in a Kuwaiti population. Methods: Expression frequencies of the MHC were measured in 26 Kuwaiti patients with psoriasis, and 60 control individuals were matched for age, sex and ethnic background. Tissue typing for class I and class II antigens was carried out by lymphocytotoxicity assays. Results: HLA-CW6, DQ2 and DQ7 were significantly increased in patients compared to controls (p = 0.0002, 0.0044 and 0.0004, respectively), while HLA-B7, DR5 and DR52 were significantly decreased (p = 0.002, 0.0004, 0.019, respectively). Conclusion: These findings suggest that psoriasis is associated with HLA-CW6, DQ2 and DQ7 in the Kuwaiti population. Further studies to investigate the association of distinct HLA with psoriasis vulgaris based on the RNA levels are under way.

Summary Background. Chronic urticaria is a common disease with an unclear pathogenesis, which may be resistant to therapy. Recent studies have focused primarily on a possible autoimmune basis. Aim. To investigate HLA class I and II antigens in a Turkish population with chronic ordinary urticaria (COU; not physical, vasculitic or contact), and identify susceptible HLA antigens. Methods. HLA antigens were investigated in 55 patients diagnosed with COU, using a two-stage microdroplet lymphocytotoxicity test, with 104 healthy and genetically unrelated individuals evaluated as the control group. Results. HLA Bw4 and HLA DQ1 antigens were significantly higher in the study group (odds ratio (OR) = 2.93, 95% CI 1.47–5.85, P = 0.003 and OR = 7.81, 95% CI 1.96–28.50, P = 0.001, respectively) whereas HLA-A24 antigen was higher in controls (OR = 0.36, 95% CI 0.15–0.86, P = 0.03). Conclusion. We propose that HLA-Bw4 and DQ1 antigens may be responsible for susceptibility to COU while HLA-A24 may have a protective role in the Turkish population.

The antibody monitoring system (AMS, GTI Inc) is a solid enzyme-linked immunosorbent assay (ELISA) crossmatch test for the detection of immunoglobulin G (IgG) antibody to donor-specific solubilized HLA class I and class II antigens. The objective of this study was to compare the results of the AMS assay with donor-specific anti-HLA IgG antibodies (DS-HLA Abs), as determined by ELISA panel reactive antibody (PRA) and the flow cytometric crossmatch test (FCXM). A total of 107 sera were screened for the presence of HLA Abs by ELISA PRA (LAT-M, One-Lambda Inc), the DS-HLA Abs were determined in 34 serum samples (31.8%) by an ELISA panel (LAT class I and class II, One-Lambda Inc) and FCXM. The FCXM and AMS assays were performed with matched lymphocytes from 56 donors. There was a significant degree of concordance (89.7%) between the two tests (P < .001). The sensitivity, specificity, positive predictive value, and negative predictive value of AMS assay to detect DS-HLA Abs was 88.2%, 94.5%, 88.2%, and 94.5%, respectively. The AMS is a simple, objective test, which has several advantages over the cell-based crossmatch test, such as elimination of non-HLA antibody reactivity, elimination of non-donor-specific antibody reactivity, no need for viable cells, and preparation of the donor's HLA antigens in advance. In summary, this study suggested that AMS may be useful as a supportive crossmatch test or as a monitoring test after transplantation to detect class I or class II DS-HLA Abs.

The present study examined the role of CD4+ and CD8+ T cells in cardiac allograft rejection when either the direct or indirect pathway was eliminated for the CD4+ portion of the response. To study the pathways in vivo, we used genetically altered mouse strains that lack class II antigens as either the donors or recipients for cardiac transplantation. In contrast to earlier published studies, which used different strain combinations, we found that either CD4- or CD8-depletion prolonged cardiac allograft survival moderately, but not indefinitely, in an MHC-mismatched, minor-matched combination. When the CD4+ indirect pathway was eliminated, rapid graft rejection occurred when both T-cell subsets were present and when either CD4+ or CD8+ T cells were depleted. When the CD4+ direct pathway was eliminated, rapid graft rejection occurred when both T-cell subsets were present, there was slow rejection when CD4+ T cells were eliminated, and no rejection was seen for more than 100 days when CD8+ T cells were eliminated. However, the long-surviving allografts on the recipients with only CD4+ cells and an indirect pathway did show evidence of chronic vasculopathy. Thus, either CD4+ or CD8+ T cells can mediate acute cardiac allograft rejection in these experiments when both pathways are available. In addition, CD4+ T cells can provide help for acute rejection through either the direct or indirect pathway. Finally, recipients who have only CD4+ cells and an indirect pathway do not demonstrate acute rejection, but do show evidence of chronic rejection.

Flow cytometry is a powerful technique for T-cell crossmatching but is prone to false-positive reactions with B cells. In this study the flow cytometry crossmatch (FCXM) was performed in 319 cases, using the patient's serum untreated and incubated at 56 degrees C for 30 minutes. Heat treatment inhibited B-cell reactivity in 30 of 39 cases. Flow cytometry testing with latex beads coated with human leukocyte antigen (HLA) class II antigens showed no class II antibodies in sera that were completely inhibited by heat treatment. There was no inhibition of class I antibodies to either T or B cells, or of class II antibodies to B cells. Experiments with aggregated IgG showed that inhibition by heat treatment is likely due to the prevention of complement binding to aggregates or dissociation of aggregates, or both. We conclude that heat inactivation is a simple step that eliminates false-positive reactions in the B-cell flow cytometry crossmatch.

Aim This study compares the relative merits of a new HLA typing product soon to be available to laboratories in the USA – Biofortuna SSPGo HLA typing reagents marketed by Abbott to HLA typing reagents currently used in our laboratory. Evaluation points include reagent storage, ease of running the assay, reliability of the reagents, and comparability to established products. In a double-blinded study, we used the DNA of 100 patients, whose HLA antigens were well defined using lab-established SSO and/or SSP technologies. These patient HLA antigens covered 99% of all serologically defined HLA-A, B, C, DR and DQ antigens. Methods HLA testing using the SSPGo typing reagents for Class I and Class II antigens were per manufacturer’s instructions using standard protocols. Shipment and storage of reagents were at ambient temperature. Results of the SSPGo typings were performed manually using manufacturer provided worksheets and also using the Biofortuna Verdict Interpretation software provided. Results The time needed to perform the SSPGo HLA typing was comparable to the time needed to perform HLA typing using established reagents. The Verdict software was easy to use and 100% accurate as compared to manual analysis. The concordance of HLA typing results between SSPGo HLA typing reagents and those in current use in our laboratory was 98% for Class I reagents, and 99% for Class II reagents. The failure rate of the SSPGo reagents was 0.3% overall. The ambiguity rate was 0.1%. Conclusions The Biofortuna SSPGo HLA typing reagents had the advantage of room temperature shipping and storage conditions, which is extremely helpful in laboratories short on freezer space. Their testing was comparable to established laboratory protocols in ease of use and time of set-up and interpretation, and was comparable in both HLA Class I and Class II typing results and ambiguity rates to what we are currently using in our laboratory. The SSPGo reagents had a slightly lower failure rate than what we are currently using.

Retinal pigment epithelial cells (RPE) were derived from bulbi of cornea donors and maintained in culture. The time-span between donor's death and cell cultivation ranged from 2 to 122 h. The mean numbers of hours was 25.6 (n = 130). After IFN-gamma stimulation, cells were serologically typed for class I and class II antigens. Unclear class I allospecificities were verified by one-dimensional isoelectric focusing. Data from the serological typing of lymphocytes and those of the serological and biochemical typing of RPE from the same donors were compared in 22 cases. There was a discrepancy of less than 5%, whereby either the typing on lymphocytes could not identify some specificities declared as blanks or the RPE typing had failed to clearly define a specificity. Our data show that the strategy adopted here is very successful for tissue typing post mortem, thus increasing the number of available HLA-matched corneas and consequently reducing the number of corneal graft rejections.

Objective. To determine the frequency of HLA class I and II antigens in Caucasian North American patients with Takayasu arteritis (TA). Methods. Seventy-three class I antigens and 13 class II antigens were examined in 21 Caucasian North American patients with TA, and their frequencies were compared with findings in 243 healthy, untreated controls. HLA typing was performed by microlymphocytotoxicity assay. Results. We found no statistically significant positive association of TA with DR2, DR4, DQw3, or any of the other class I or class II antigens studied. A negative association between TA and DR1 was noted. There was no significant association between any of the HLA antigens and the severity of the disease or the presence of complications. Conclusion. The negative association between TA and the DR1 antigen suggests that this antigen may be protective against the development of the disease.

Previously, several groups reported an increase in HLA antigen-sharing in couples suffering from unexplained repeated spontaneous abortions. It was felt necessary to find out if HLA sharing could have any effect on children born after a successful pregnancy. The birthweight figures of children of 76 couples with repeated spontaneous abortions were analyzed. The results show a significantly lower birthweight in babies born from those couples, presenting a high incidence of HLA antigen-sharing, particularly concerning class II antigens.