Abstract

Patients with schistosomiasis of the urinary bladder (SB) associated with carcinoma of the bladder (SCB) or carcinoma of the prostate (SCP) have a variety of immunologic abnormalities, including the presence of HLA-DR+ and interleukin-2 receptor-positive (IL-2R+) T-lymphocytes in circulating blood. This study demonstrated that, the HLA-DR+ and IL-2R+ antigens are selectively expressed on majority of the CD4+ T-lymphocytes of patients with SCB, whereas, these antigens are expressed almost equally on both CD4+ and CD8+ T-lymphocytes of patients with SB and SCP. Expressions of HLA-DR+ and IL-2R+ antigens in CD4+ T-lymphocytes, and a depressed response of this T-cell subset to phytohemagglutinin and Concanavalin A stimulations seems to be the characteristic feature of these patients with SCB. In addition, the autologous mixed lymphocyte reaction (AMLR) and allogenic mixed lymphocyte reaction (MLR) was depressed in patients with SCB. However, patients with SCP demonstrated a normal MLR, even though the AMLR was highly depressed. The immunoregulatory role of the HLA-DR+, IL-2R+, CD4+ helper/inducer T-lymphocytes, and the AMLR and MLR abnormalities we have identified in patients with SCB may be important and could play a role in the pathobiology of these diseases in humans.