PCR testing for HCV in anti-HCV negative blood donors involved in the so called HCV +ve post-transfusion hepatitis

The significance of transfusion in the past as a risk for current hepatitis B and hepatitis C infection: a study in endoscopy patients

BACKGROUND

The objective was to determine the contribution of transfusion in the past to the risk of current infection with hepatitis B or C among patients attending a large hospital for endoscopic procedures.

STUDY DESIGN AND METHODS

Blood samples had been tested for hepatitis markers by routine methods. Patients completed a comprehensive risk factor questionnaire and results were analyzed using computer software.

RESULTS

Twenty-seven percent of the 2120 participants in the study received transfusions in the past. There was no increase in prevalence of hepatitis B among those transfused. Compared with nontransfused participants, recipients of blood before the implementation of hepatitis C virus (HCV) screening in 1990 had a 4.6-fold increased risk of HCV infection, whereas those transfused with screened blood had a 3-fold increased risk. The difference between the odds ratios for patients before and after screening was not significant.

CONCLUSIONS

Because screening has almost completely eliminated HCV from the blood supply, our finding of a continuing association of HCV infection with transfusion was unexpected. It implies that there are significant other nosocomial risks for hepatitis C transmission associated with the clinical situations where patients received blood. These should be actively investigated.

Positively charged porphyrins: a new series of photosensitizers for sterilization of RBCs

BACKGROUND

Photodynamic treatment could be a way to inactivate pathogens in RBCs. The objective of this study was to characterize the virucidal activity and RBC-damaging activity of a series of cationic porphyrins. Using the most efficacious photosensitizer, various in-vitro human RBC quality variables and in-vivo RBC survival in Rhesus monkeys were evaluated.

STUDY DESIGN AND METHODS

RBCs, spiked with 5 log of extracellular VSV, were treated with porphyrins (25 micro mol/L) and red light (100 W/m2) and essayed for virucidal activity. In-vitro RBC quality variables were assessed during 5 weeks of storage in various ASs. In-vivo survival was investigated with autologous RBCs in Rhesus monkeys.

RESULTS

Tri-P(4) was by far the best sensitizer of a series tested, giving the least hemolysis under conditions that resulted in 5 log-kill of extracellular VSV. Under our experimental conditions, the percentage hemolysis in treated cells was 5.1 +/- 1.1 percent after 5 weeks of storage in SAG-M compared to 1.9 +/- 1.1 percent in the untreated control. Storage in AS-3 resulted hemolysis of 2.3 +/- 1.9 percent. With the exception of IgG binding and potassium leakage, RBC quality variables remained unchanged after photodynamic treatment. Addition of reduced glutathione (GSH) during treatment reduced IgG binding. The 24-hour recovery and T50 of treated RBCs in Rhesus monkeys were satisfactory.

CONCLUSION

Porphyrin Tri-P(4) may be a suitable photosensitizer for sterilization of RBCs. However, further exploration to optimize the method is necessary to reach clinically acceptable goals.

Transfusion transmitted diseases

Transfusion transmitted disease (TTD) is a major challenge to the transfusion services all over the world. The problem of TTD is directly proportionate to the prevalence of the infection in the blood donor community. In India, hepatitis B/C, HIV, malaria, syphilis, cytomegalo virus, parvo-virus B-19 and bacterial infections are important causes of concern. Hepatitis B and C infections are prevalent in India and carrier rate is about 1-5% and 1%, respectively. Post transfusion hepatitis B/C is a major problem in India (about 10%) because of low viraemia and mutant strain undetectable by routine ELISA. HIV prevalence among blood donors is different in various parts of the country. It may not be so alarming as projected by some agencies. In one study from north India, confirmed HIV positivity was found in 0.2/1000 blood donor. Post transfusion CMV is difficult to prevent but use of leukocyte filters may help to reduce it significantly. Parvo virus B-19 infection in blood donors is 39.9% which may increase morbidity in multitransfused or immunocompromised patients. Current symphilis tests may not be sensitive but it should be continued to exclude high-risk donors. Malaria is a real problem for India due to the lack of a simple and sensitive screening test. Incidence of bacterial contamination is greatly reduced due to improved collection/preservation techniques and use of antibiotics in patients. However, proper vigilance and quality control is needed to prevent this problem. Total dependence of altruistic repeat voluntary donors and use of sensitive laboratory tests may help Indian blood transfusion services to reduce incidences of TTDs.