Frequencies of GB virus C/hepatitis G virus genomes and of specific antibodies in German risk and non-risk populations.

The prevalence of the new flavivirus GB virus C/hepatitis virus G (GBV-C/HGV) in different German populations was investigated by detection of viral genomes and anti-E2 antibodies. While blood donors had an overall prevalence of 10.4% there were increased rates for hemophiliacs (54.7%), hemodialysis patients (30.2%), male homosexuals (30.2%) and intravenous drug users (74.4). Most GBV-C/HGV positive samples were either viral genome positive or antibody positive, exclusively. Samples with the rare constellation "positive for both GBV-C/HGV genome and specific antibody" originated in almost all cases from patients who were additionally infected with HIV or HCV. Probable transmission of GBV-C/HGV by PCR-positive blood transfusions was observed in 5 of 6 cases approximately six months after transfusion.

Human immunodeficiency virus antibody screening in patients on renal replacement therapy: prevalence of false-positive results.

Patients with terminal renal failure quite frequently receive blood transfusions on renal replacement therapy; therefore they are at increased risk of infection with human immunodeficiency virus (HIV). We investigated sera from 380 patients on haemodialysis or with a renal transplant for anti-HIV, using commercially available enzyme immunoassays (EIA). Persistent EIA-positive sera were additionally examined by Western blot and ELAVIA test, a commercially available indirect EIA. We found 20 patients (5.3%) with a persistently positive EIA screening test. None gave a positive result with confirmatory tests. Cross-reacting leucocyte antibodies seemed to be responsible for most of these false-positive anti-HIV tests; 12 of 20 EIA-positive sera were found positive for HLA antibodies. Sera from patients on haemodialysis or with a renal transplant, particularly when multiply transfused, have to be investigated carefully before infection with HIV is confirmed.

Reversal of acute vascular rejection by plasma exchange.

The vast majority of grafts with acute vascular rejection (AVR) undergo irreversible loss of function, since this type of rejection usually does not respond to increased levels of immunosuppression. Since 1980 we have treated with plasmafiltration (PF) 14 steroid resistant episodes of AVR in 10 patients. In the treatment of each episode 6 X 5 L plasma were filtered and simultaneously replaced with 3.5% albumin-Ringer-lactate solution. After each PF, 20 g immunoglobulins (Intraglobin) were replaced i.v. In all cases following PF renal function improved. One graft was eventually lost as a result of chronic irreversible vascular rejection; all others are still functioning. Eight of the 10 patients have been observed now for at least 6 months since beginning PF treatment and 5 of these 8 have been followed for more than 12 months. None of them shows signs of rejection. PF with replacement of immunoglobulins after treatment appears to be a simple and safe procedure, which in our hands proved to be quite effective in reversing AVR.

Improved graft prognosis by treatment of steroid resistant rejections with ATG and plasmapheresis.

Conventional therapy of acute rejection is almost exclusively based on increased steroid dosage, however, a considerable number of grafts undergo irreversible steroid resistant rejection (SRR). We investigated in a prospective study the effects of antithymocyte globulin (ATG) and plasmafiltration (PF) in cases of SRR. Acute interstitial rejections were treated with ATG, acute vascular rejections with PF. Thirty-nine of 42 (93%) cases of SRR were reversed by these forms of therapy. In 68 recipients of first cadaveric renal allografts actuarial one year graft survival has improved to 88 (+/- 5) per cent since the introduction of ATG and PF for SRR. Severe side effects or increased mortality were not observed, none of the patients with either form of therapy died. Thus ATG and PF are valuable adjuncts in the treatment of SRR.