ABSTRACT
As incidence of SLE is high in Blacks, we studied HLA and SLE associations in the French West Indies, whose population is racially mixed. Forty-seven coloured SLE patients have been typed in HLA A,B,C and DR. We observed B8 association in nearly all of the studies. B15 association, more frequent in Caucasians, was found, also B53 association, a Black variant of B5 more frequent in Blacks. We did not find any class II association.
Subject(s)
HLA Antigens/analysis , HLA-D Antigens/analysis , HLA-DR Antigens/analysis , Lupus Erythematosus, Systemic/genetics , HLA Antigens/genetics , HLA-DR Antigens/genetics , Humans , Lupus Erythematosus, Systemic/immunology , West IndiesABSTRACT
Homozygous sickle cell disease patients have an increased risk of developing severe infections, probably because of impaired immunity. Cellular immunity was studied in thirty-two patients with S homozygous haemoglobin (SS) and compared to 32 A homozygous haemoglobin (AA) healthy subjects. A leukocytosis was observed but with a significant diminution of T4 and T8 proportions in sickle cell patients. B lymphocytes, concanavalin A, phytohaemagglutinin, and phorbol myristate acetate-induced lymphocyte proliferation were not different between the two groups except for enhanced pokeweed mitogen stimulation in SS patients. In contrast, addition of autologous sera to mitogen-induced cultures resulted in a potentiation of lymphocyte proliferation significantly greater in patients with S homozygous haemoglobin when compared to subjects with A homozygous haemoglobin. This highly amplified mitogen-induced response of lymphocytes by SS autologous sera, when compared to AA autologous sera, was not observed when these sera were added to lymphocytes obtained from an allogenic healthy individual. In vivo interleukin 2 production and natural killer activity were not different between SS and AA individuals. We conclude that there are functional abnormalities of cell-mediated immunity in patients with sickle cell anaemia and the SS lymphocyte activation by autologous sera was probably due to infectious and drepanocytic antigenic determinants contained in SS serum.
Subject(s)
Anemia, Sickle Cell/immunology , Hemoglobin A/analysis , Hemoglobin, Sickle/analysis , T-Lymphocytes/immunology , Adolescent , Adult , Anemia, Sickle Cell/blood , Child , Child, Preschool , Female , Humans , Immunity, Cellular , Leukocyte Count , MaleABSTRACT
Patients with sickle cell anemia (SCA) had an abnormal susceptibility to infections. In Martinique (French West Indies), a human T-cell leukemia/lymphoma virus type I (HTLV-I) endemic area, we found that 17 (10%) of 173 SCA patients had antibodies to HTLV-I. The possible relationship between HTLV-I seropositivity and altered immunity was studied in 13 SCA patients with HTLV-I antibodies compared with 13 matched SCA patients without HTLV-I antibodies. The immunological results, as evaluated by the T-cell subsets analysis, the lymphocyte proliferation responses analyzed after activation with concanavalin A, phytohemagglutinin, or pokeweed mitogen, and the natural killer activity were not statistically different in these two groups of patients (SCA HTLV-I positive vs SCA HTLV-I negative). These data suggest that HTLV-I infection did not result in a major alteration of cellular immunity in this population.
Subject(s)
Anemia, Sickle Cell/immunology , Antibodies, Viral/analysis , Deltaretrovirus Antibodies , Humans , Immunity, Cellular , Killer Cells, Natural/immunology , Lymphocyte Activation , Lymphocytes/classification , T-Lymphocytes, Regulatory/immunology , West IndiesABSTRACT
The genetic polymorphism previously reported to be associated with the sickle-cell (beta S) gene in black U.S.A. citizens was studied in the population of two French West-Indies islands in order to evaluate its potential application to the antenatal diagnosis of sickle-cell anaemia. The polymorphism consists of a change in the DNA sequences located near the 3' end of the beta globin gene. The change can be detected by means of the restriction endonuclease Hpa I. When cellular DNA is digested with this enzyme, the beta globin gene is contained in a DNA fragment measuring either 7.6 or 13.0 kilobases (kb). In 70% of SS homozygous subjects in Martinique and 57% in Guadeloupe the beta S gene was carried by a 13.0 kb DNA fragment, whereas the normal beta A gene was carried by a 7.6 kb DNA fragment. This polymorphism would make it possible to detect the foetal beta S gene in the DNA of amniotic fluid cells by linkage analysis.