Immunologic studies in patients with chyluria.

Patients with chyluria, postoperative chylothorax, or surgical thoracic duct drainage are depleted of lymphocytes, IgA, and C3 as a result of the loss of lymphatic cellular and humoral elements, but the specific defects have not been well characterized. Therefore, we investigated the immunologic status of three patients with longstanding chyluria who were lymphopenic but did not have evidence of opportunistic infections. All patients had normal levels of immunoglobulins except for a moderate decrease in the IgA fraction, a normal antibody response to viral agents, and a normal hypersensitivity response to at least one of six recall antigens. Their complement levels were essentially normal. All were leukopenic because of decreased numbers of circulating lymphocytes. Two had depressed relative and absolute numbers of OKT4 (helper/inducer) T cells and normal or increased relative numbers of OKT8 (cytotoxic/suppressor) T cells, resulting in a marked reversal of the OKT4 to OKT8 ratio. The third was severely depleted of both OKT4 and OKT8 cells. The response of their peripheral blood mononuclear cells to mitogen stimulation was reduced, but they all had normal or increased absolute and relative numbers of natural killer (NK) cells as defined by HNK-1 or OKM-1. Their NK activity was less than that of normal controls unless stimulated by interferon, suggesting that many of the NK cells were immature. Normal delayed hypersensitivity, reduced but effective mitogen stimulation, and a normal NK response after interferon may be factors that protect these patients against opportunistic infections and neoplasms.