title: A functional defect in the early phase of the immune response observed in patients with hemophilia A.
abstract: In search of a functional immunological defect in patients with hemophilia A, we investigated the early phase of the immune response and found a deficiency in the monocyte-T cell interaction after in vitro exposure to a bacterial antigen. T-cell proliferation in response to Escherichia coli-pulsed autologous monocytes was significantly (P less than 0.025) reduced in hemophiliacs [mean dpm +/- SEM (n = 25): 9036 +/- 2600] as compared to healthy controls [mean dpm +/- SEM (n = 24): 17,812 +/- 2985]. This functional defect was expressed in a severe form (antigen-induced monocyte-T cell interaction less than or equal to 2000 dpm) in both HTLV III antibody-positive and -negative patient populations. Significantly decreased T-helper/T-suppressor-cell ratios (mean dpm +/- SEM: patients 1.47 +/- 0.13; controls 2.04 +/- 0.11; P less than 0.001)--but without a concomitant reduction in the absolute number of T-helper cells--could also be observed.
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000209:etiology; D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000032:analysis; D002648:Child; D017977:Deltaretrovirus / Q000276:immunology; D004926:Escherichia coli / Q000276:immunology; D005169:Factor VIII / Q000627:therapeutic use; D006467:Hemophilia A / Q000276:immunology*; D006801:Humans; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer
chemical_list: D000914:Antibodies, Viral; D005169:Factor VIII