Electro Nucleonics, Inc.

Serum from 60 patients with hairy cell leukemia (HCL) were studied for the presence and the titers of antibodies to Epstein-Barr virus (EBV), cytomegalovirus (CMV) and human T-cell lymphotrophic viruses (HTLV). Eighty-three percent of the patients were seropositive for EBV, with a (reciprocal) geometric mean titer (GMT) of 960. Seventy-eight percent of the patients had antibodies to CMV with a GMT of 435. All 21 patients tested for HTLV I and HTLV III were seronegative; only one patient showed detectable antibodies to HTLV II. The potential role of these infections in the physiopathology of HCL is discussed.

Our homogeneous immunoprecipitation inhibition assay (Clin. Chem. 28:659-661, 1982) is applied here to tobramycin, phenobarbital, and theophylline. Only 10-50 microL of test sample is needed. No sample treatment, dilution, or extraction is required. A test serum sample is simultaneously mixed with a drug conjugate and its specific antiserum in a centrifugal analyzer. The subsequent reaction and the measurement are completed in 3 min. Within-run and between-run CVs for clinically relevant concentrations were well below 10%. Results for patients' samples correlated well with those by enzyme immunoassay.

A new homogeneous immunoprecipitation inhibition assay has been developed to quantitate concentrations of hapten in human serum or plasma without the use of radioactive isotopes, enzymes, fluorescent markers, or laser nephelometers. This immunoprecipitation is based on spectrophotometric measurement of the inhibition by free hapten of the precipitating reaction between antihapten antibody and polyhaptenic antigen. The immunoprecipitation analysis of the antibiotic gentamicin in human serum is reported here. A serum test sample is mixed with gentamicin-human serum albumin polyhaptenic conjugate and rabbit antiserum to gentamicin on a centrifugal analyzer, and the subsequent reaction monitored for 3 min. No sample dilution or pretreatment is required. The within-run and between-run coefficients of variation are well below 10%. The results on patients' test samples correlate well with those obtained by commercially available radioimmunoassay and enzyme immunoassay kits.