HLA-DRB1 and DQB1 allele distribution in the Muong population exposed to malaria in Vietnam.

The distribution of 30 HLA-DRB1 alleles in 85 individuals and of 10 HLA-DQB1 alleles in 91 individuals of the Viet Muong population was studied and compared with those of nine other Asian populations, including 103 Viet Kinh belonging to the major ethnic group in Vietnam. In terms of genetic distance, our data are consistent with a close ethnogeographic relationship between Viet Muong, Buyi and Dai Lue, two Southern Chinese ethnic groups. Conversely, these three populations are distant from the Northern Chinese population. The Viet Kinh belong to an intermediate group, together with North-eastern Thais, Thais and present day Thais. The striking presence of the HLA-DQ1*0502 allele (48% frequency) in the Viet Muongs is possibly anthropological or environmental in origin: the Viet Muongs have been submitted to endemic malaria for centuries, and the survivors carry the protective trait of glucose-6-phosphate dehydrogenase deficiency. This raises the hypothesis of a possible resistance to lethal or severe forms of the disease, where the association with a specific HLA-DQB1 allele may play a role.

[Influence of the anti-HLA immunization profile before grafting on the outcome of renal transplant]. / Influence du profil d'immunisation anti-HLA avant greffe sur le devenir du greffon renal.

A retrospective study of HLA immunization profile before a first graft of unrelated kidney in 212 immunized recipients (with an initial peak greater than or equal to 25%) shows that one can define at least 3 groups of responder with a different graft outcome. Recipients with either weak or strong variance of HLA antibody (VP) before graft (group I: VP less than 230 and group III: VP greater than 830) have a significantly lower graft survival: 54% (p = 0.006) and 45% (p = 0.002) respectively at 4 years, than recipients of group II (230 less than VP less than 830) for whom the prognosis is of 77% after the same time period. If similar results are observed on independent series, VP would be of a great interest for the definition of a new classification of responders, and on a practical level for the choice of renal transplant.

Influence of HLA-A, B, and DR matching on the outcome of kidney transplant survival in preimmunized patients.

The outcome of 893 prospectively typed (HLA-A, B, and DR) and matched cadaveric kidney transplants--all first grafts, with patients being transfused before transplantation--was studied using actuarial survival methods. The effect of HLA-A, B and DR matching was only found to be significantly beneficial to graft survival in the group of 289 presensitized recipients: 70% and 43% graft survival at two years in the case of best-matched (4-6 HLA-A, B, and DR) identities versus mismatched (0 and 1 HLA-A, B, and DR) identities, respectively (P = 0.05). Although a cumulative effect of matching for antigens belonging to the 3 HLA-A, B, and DR series was observed among the group of preimmunized recipients, a trend arose in favor of the prominent role of the HLA-B alleles. No significant difference related to HLA matching was observed in the group of nonsensitized recipients. These results confirm previous observations and support efforts to give priority for matched kidneys to preimmunized patients.

[Role of transfusions and significance of HLA-A, B and DR compatibility in renal transplants]. / Rôle des transfusions et importance de la compatibilité HLA-A, B et DR chez les transplantés rénaux.

The results study of renal allograft performed in the France-Transplant network, shows the beneficial effect of blood transfusions on graft survival; their immuno-suppressive effect allowed the tolerance of the transplant, despite of the presence, at times, of incompatibilities HLA. In this work, we have studied the effect of HLA-A, B, DR incompatibilities in 803 unrelated recipients according to their preimmunized status. In the 303 presensitized patients (by transfusion or transplantation) we show clearly the strong effect of the HLA compatibility and the additive effect of the three loci A, B, DR (94% of graft survival at two years for the best matched v.s. 36% for the worst). In the 500 non responder patients, there is no effect of the compatibility A, B, DR (69% for the best matched v.s. 71% for the worst). Presensitized patients reach currently 50% of the waiting list of dialysed. Cooperative efforts should avoid heavily mismatched transplants in case of preimmunization.

Glomerular lesions in monoclonal gammopathies and mixed essential cryoglobulinemias IgG-IgM.

Histologic studies of renal tissue were performed in 21 cases of IgG or IgA benign monoclonal gammopathy, in 19 cases of IgM monoclonal gammopathy, and in 11 cases of mixed idiopathic IgG-IgM cryoglobulinemias. Except for myeloma, glomerular lesions were very frequent. Amyloidosis was found in one patient with myeloma, in two with benign IgG gammopathy, and in three with Waldenström macroglobulinemia. Intraglomerular deposits were found in 13 patients. In 7 of these patients (6 with Waldenström macroglobulinemia, 1 with benign IgA monoclonal gammopathy), the deposits were isolated without cellular proliferation. In the other 6 patients (one with benign IgG monoclonal gammopathy, five with IgG-IgM cryoglobulinemias) the deposits were associated with severe endocapillary proliferation. Immunohistologic study showed the presence of immunoglobulins in these deposits. The immunoglobulin(s) present in the glomerular deposits was (were) similar to the serum monoclonal immunoglobulin or immunoglobulins of the cryoglobulin. Crystals were found in the glomerular endothelial cells in one case of benign IgG gammopathy. The significance of these lesions is briefly discussed.