[Immunologic laboratory tests in acquired immunodeficiency syndrome (AIDS) and suspected AIDS].

Since AIDS-specific laboratory tests are not yet commercially available, laboratory diagnoses of AIDS or of the AIDS-related complex (ARC) are based on "surrogate markers". While single tests are of limited diagnostic value, test combinations are of greater help. However, these tests should be applied restrictively and stepwise. The following parameters were analyzed in respect of their diagnostic and differential-diagnostic value: absolute number of lymphocytes, delayed type hypersensitivity skin tests to seven recall antigens, beta-2-microglobulin, serum-neopterin, C-reactive protein, complement factor B, circulating immune complexes, immunoglobulins, hepatitis B markers, and the ratio of T helper to T suppressor cells. 14 AIDS patients, 11 ARC patients, 23 healthy homosexuals, 6 iv drug users, 6 hemophiliacs and 35 patients with various other disorders were investigated. To analyse the value of a given test or of test combinations in the diagnosis of AIDS and ARC, a discrimination index was introduced and defined as the difference between the percentage of pathological values in one patient group compared to the percentage of pathological values in the other group. A discrimination index of 100 means that a given test is pathologic in all members of one group and negative in all members of the other group. A discrimination index of 60 may mean 80% of pathological values in one group versus 20% in the other. To distinguish AIDS patients from ARC patients the test combination yielding the highest mean discrimination index included serum neopterin, complement factor B and C-reactive protein.(ABSTRACT TRUNCATED AT 250 WORDS)