Prevalence and induction of circulating antibodies against recombinant staphylokinase

Streptokinase (SK) is a routinely used thrombolytic agent but it is immunogenic and allergenic; staphylokinase (STA) is a potential alternative agent which is under early clinical evaluation. The comparative prevalence of antibodies against recombinant STA (STAR) and against SK was studied in healthy subjects and their induction with intravenous administration in small groups of patients. Enzyme-linked immunosorbent assays, using microtiter plates coated with STAR or SK and calibration with affinospecific human antibodies, revealed 2.1 to 65 micrograms/ml (median 11 micrograms/ml) anti-STAR antibodies and 0.9 to 370 micrograms/ml (median 18 micrograms/ml) anti-SK antibodies (p < 0.001 vs anti-STAR antibodies) in plasma from 100 blood donors, with corresponding values of 0.6 to 100 micrograms/ml (median 7.1 micrograms/ml) and 0.4 to 120 micrograms/ml (median 7.3 micrograms/ml), respectively, in 104 patients with angina pectoris. Three out of 17 patients with Staphylococcus aureus bacteremia had significantly increased anti-STAR antibody levels (150, 75 and 75 micrograms/ml), and STAR neutralizing activities (2.2, 3.6 and 4.1 micrograms STAR neutralized per ml plasma, respectively). In 6 patients with acute myocardial infarction, given 10 mg STAR intravenously over 30 min, median anti-STAR antibody levels were 3.5 micrograms/ml at baseline, 2.9 micrograms/ml at 6 to 8 days and 1.2 mg/ml at 2 to 9 weeks, with median corresponding titers of STAR neutralizing activity at 2 to 9 weeks of 42 micrograms/ml plasma. Conversely, in 5 patients treated with 1,500,000 units SK over 60 min, median anti-SK antibodies increased from 2.9 micrograms/ml at baseline to 360 micrograms/ml at 5 to 10 days, with corresponding median SK neutralizing activities of 13 micrograms/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis C among risk groups for HIV and hepatitis B

In order to obtain more information on sexual transmission of hepatitis C (HCV) we compared different high-risk groups for HIV and hepatitis B to see if they were seropositive for HCV. A high seroprevalence (38/81) of hepatitis C (HCV) was found among intravenous drug users. Nursing staff (n = 35) and patients of a dialysis unit (n = 57) had a low prevalence of anti-HCV antibodies (0% and 5%, respectively). Serology laboratory technicians also had a very low prevalence (0% out of 29). Among prostitutes (n = 114), healthy homosexual men (n = 132) and HIV-infected homosexual men (n = 31), we found a remarkably low seroprevalence of HCV (3.5%, 0.8% and 0.0% respectively). These data support the view that parenteral exposure to the virus is the most important way of acquiring the infection and that neither heterosexual nor homosexual promiscuity are associated with a high risk of transmission of hepatitis C.