Relationship between guanase activity in donor blood and the incidence of posttransfusional non-A, non-B hepatitis, and a possible method for preventing posttransfusional hepatitis

HCV infection and its clinical features in recipients of blood screened for HCV (C100-3) antibody

After adoption of the anti-hepatitis C virus (C100-3) test, the incidences of definite and suspected cases of post-transfusional hepatitis (PTH) were 3.3% (7/209) and 7.2% (15/209), respectively. Four patients with definite PTH and seven patients with suspected PTH became positive for hepatitis C virus (HCV)-related antibodies or HCV-RNA after transfusion. These cases that became positive for anti-HCV or HCV-RNA showed a peak of alanine aminotransferase (ALT) more than 4 weeks after operation. Only rare cases that showed ALT peaks within 4 weeks after operation became positive for HCV-related antibodies or HCV-RNA. The peak ALT levels in cases showing positive conversion tended to be higher than those in cases showing no conversion. Judging from these results, cases of suspected PTH include those of transient liver disease attributable to surgery as well as clear cases of HCV infection. Thus new diagnostic criteria are required including data on HCV antibodies or HCV-RNA.

Epidemiological characteristics of the incidence of hepatitis C virus (C100-3) antibodies in patients with liver diseases in the inshore area of the Yangtze River

The Nantong area is an endemic region of hepatitis B virus (HBV) infection in the inshore area of the Yangtze River. However, no detailed data are available about hepatitis C virus (HCV) infection in this area. In this study recent reports are reviewed about the incidence of viral hepatitis and primary hepatocellular carcinoma (PHC) in China, and it is shown that the Nantong area is a high risk region for PHC. This study reports on the incidence of antibody to HCV (anti-HCV) in patients with chronic liver diseases in the Nantong area; investigated in collaboration with members of the Nantong Medical College, Jiangsu Province, the People's Republic of China. The incidence of anti-HCV (C100-3) in the Nantong area was: 0.67% (three of 451) in donor blood; 0.0% (none of 89) in patients with acute hepatitis; 2.7% (five of 186) in those with chronic hepatitis, 4.5% (two of 44) in those with liver cirrhosis; 6.3% (one of 16) in those with PHC; and 1.3% (one of 78) in patients without liver disease. The incidence of hepatitis B surface antigen in the Nantong area was: 15.7% (14 of 89) in patients with acute hepatitis; 81.2% (151 of 186) in those with chronic hepatitis; 81.8% (36 of 44) in those with liver cirrhosis; 87.5% (14 of 16) in those with PHC; and 20.5% (16 of 78) in patients without liver disease. Although the Nantong area is a high risk region for PHC, these data suggest that HCV infection is not an important aetiological factor for PHC in this area.

Post-transfusional anti-HCV-negative, non-A, non-B hepatitis. (I) a prospective clinical and epidemiological survey

Despite the identification of hepatitis C virus (HCV) and the detection of anti-HCV antibodies in the serum of infected individuals, a sizeable proportion of patients who develop transfusion-associated acute non-A, non-B hepatitis following surgery do not develop anti-HCV antibodies. The cause of this disease remains unknown. To assess the role of homologous blood transfusion in anti-HCV-positive and -negative, non-A, non-B hepatitis following surgery, patients receiving homologous blood, autologous blood alone, or no transfusions were prospectively studied. Consumption of potentially hepatotoxic drugs was also quantified. Anti-HCV antibodies were tested retrospectively when commercial assays became available. Of the 181 patients who received homologous blood which tested negative for surrogate markers of infectivity, 19 (10.5%) developed non-A, non-B hepatitis, associated with anti-HCV seroconversion in three cases. Of the 90 autologous blood recipients, non-A, non-B hepatitis developed in one (1.1%), who did not seroconvert to anti-HCV. Of the 64 untransfused patients, non-A, non-B hepatitis developed in one (1.6%), who was anti-HCV-positive before surgery. Logistic regression analysis showed that the occurrence of non-A, non-B hepatitis was associated with homologous blood transfusion, but not with the consumption of potentially hepatotoxic drugs. The 16 homologous-blood recipients who developed anti-HCV-negative, non-A, non-B hepatitis had received blood from 70 donors, none of whom had detectable anti-HCV antibodies but six of whom had minimal elevations of serum aminotransferase activity. Anti-HCV-negative, non-A, non-B hepatitis is mainly transfusion-transmitted in the surgical setting. Known hepatotropic agents may be involved despite the absence of usual serum markers, but our results are also consistent with the involvement of an unidentified non-A, non-B, non-C agent.

Assessment of screening tests for transfusion-associated non-A non-B hepatitis

Non-A non-B hepatitis is the most common serious sequela of blood transfusion, and its screening has become an essential goal of blood transfusion centers. Before 1989, two surrogate screening tests (for alanine aminotransferase and for antibody to hepatitis B core antigen) were used; in 1989, a direct test for the antibody to hepatitis C virus (the main agent of this hepatitis) was developed. The French National Agency for the Development of Medical Evaluation undertook an investigation to determine the optimal prevention strategy for posttransfusion non-A and non-B hepatitis (PTH). A detailed literature review was performed, complemented by expert group opinion. The performance of each test was derived indirectly by calculating the number of cases of PTH averted by each test. Hepatitis C virus testing is probably the most promising strategy, but different policies can be developed given the uncertainties of scientific data. Cost considerations should be taken into account in identifying the best screening strategy.

Post-transfusion hepatitis

Prospective international studies have shown the incidence of post-transfusion hepatitis in the 1980s to vary between 2% and 31%. Rare cases of hepatitis B continue to occur despite donor screening for the hepatitis B surface antigen, but most are of the non-A, non-B type. Non-A, non-B hepatitis is typically mild and often subclinical in the acute phase but has a tendency to become chronic in about half the affected subjects. The recently characterised hepatitis C virus has been shown to cause most, if not all, transfusion associated non-A, non-B hepatitis. Hepatitis C seropositivity seems to be associated with viraemia and infectivity among blood donors, and donor screening for these antibodies has now been instituted in many countries. New assays now being developed are improving the sensitivity and specificity of this screening, which is estimated to prevent most cases perhaps 70 to 80% of post-transfusion hepatitis.

Cost effectiveness of blood substitution in elective orthopedic operations

Cost effectiveness was compared between substitution with autologous blood, implying no risk of transmission of diseases, and homologous blood, with a definite risk of transmission. Primary and revision hip arthroplasties were included in this study, as well as scoliosis operations. The risk of contracting chronic non-A, non-B hepatitis (NANBH) was included in the calculations of the long-term economic consequences of a transmittable disease. Our study showed that predonated blood alone, with a donation of up to four units, was the most suitable and cost-effective method for substitution of blood losses up to about 2.5-3 liters A combination of predonated blood and intraoperative autotransfusion was more suitable and less expensive for substituting blood losses of 2.5 liters or more. Homologous blood was the least cost-effective alternative considering the influence of non-A, non-B hepatitis.

A prospective study of post-transfusion non-A, non-B (type C) hepatitis following cardiovascular surgery in Taiwan

In an attempt to investigate the incidence and clinical course of non-A, non-B (NANB) hepatitis following blood transfusion in Taiwan, 288 patients who underwent cardiovascular surgery and received blood transfusion were followed prospectively with serum liver aminotransferase levels and viral hepatitis markers for at least six months. None had any past history of liver disease or drug abuse. All blood donors were tested for serum hepatitis B surface antigen and alanine aminotransferase (ALT) (greater than 45 U/L). Thirty-seven (12.8%) patients developed PTH. 34 (91.9%) were considered to be cases of NANB hepatitis, 2 (5.4%) were cytomegalovirus hepatitis, and one (2.7%) was caused by Epstein-Barr virus. No one developed hepatitis B post-transfusion hepatitis (PTH). Of the 34 NANB PTH patients, 15 (44.1%) were asymptomatic, 16 (47.1%) had clinical symptoms, and 9 (26.5%) had serum total bilirubin levels higher than 2 mg/dl. There was no case of fulminant hepatic failure. Of 26 NANB PTH patients who were followed up for more than one year, 15 (57.7%) still had abnormal serum ALT levels. The incubation period of NANB PTH ranged from 2 to 16 (mean 6.1 +/- 3.2) weeks. Of the 37 PTH patients, 32 (86.5%) were found to have anti-HCV seroconversion during one year follow-up period. NANB PTH is as common in Taiwan as in the United States and Japan, and is demonstrated by this study to be due mostly to HCV.

Purification of human liver guanase and characterization of antibody against it by immunoblotting

Guanase was purified from human liver and its specific antibody was raised in rabbits. The enzyme was purified 1200-fold from the crude liver extract; the specific activity of the purified enzyme was 91.50 units/mg. The purified enzyme gave two distinct peaks on high pressure liquid ion exchange chromatography. The materials in both peaks had a molecular weight of 100,000, and were concluded to be isozymes with different pH optima for guanine. The antiserum completely inhibited the activity of the liver enzyme. It formed a single precipitin line with the human liver extract. On immunoblotting, it bound specifically to the one band with guanase activity, but to no other bands of protein. Thus, this antiserum for human liver guanase should be suitable for use in immunohistochemical demonstration of guanase and determination of this enzyme by radioimmunoassay.

Gamma-glutamyltransferase as a potential surrogate marker for detection of the non-A, non-B carrier state

Alanine aminotransferase (ALT) is currently widely used as a surrogate marker for detection of blood having a higher risk of transmission of non-A, non-B hepatitis (NANBH). Studies in the chimpanzee model, in which the NANBH carrier state is well defined, have revealed gamma-glutamyltransferase to be considerably more sensitive for the detection of NANBH carrier blood. Further study is required to determine whether this marker is also more sensitive for detection of the chronic NANBH carrier state in man.

Clinical value of the guanase screening test in donor blood for prevention of posttransfusional non-A, non-B hepatitis

We adopted an automated method for measuring guanase in donor blood and examined the incidence of posttransfusional non-A, non-B hepatitis when donor blood with high guanase activities was excluded. Sixty-seven (2.4%) of 2,826 units were excluded from use in transfusion because they had guanase activities above 1.71 units per liter. Of 112 recipients, 8 (7%) developed posttransfusional non-A, non-B hepatitis. The incidence of posttransfusional non-A, non-B hepatitis was 17% before adoption of the guanase screening test and 7% after its adoption. Thus, the incidence of posttransfusional non-A, non-B hepatitis was significantly decreased after adoption of this screening test. This study shows that, for prevention of posttransfusional non-A, non-B hepatitis, it is important to screen donor blood for guanase activity and discard blood with high activities.

Cytochemical demonstration of guanase in human liver using yellow tetrazolium

Histochemical studies of human guanase (guanine deaminase) have seldom been undertaken, in part because of technical difficulties which result in heavy background staining. We reported a modified procedure for histochemical demonstration of guanase in human tissues involving hydrolytic deamination of the substrate guanine to xanthine via guanase, and then oxidation of xanthine to uric acid, with concomitant reduction of nitrotetrazolium blue (NBT). In this report, we describe a modification of this method for cytochemical demonstration of guanase at the fine structural level using yellow tetrazolium in place of NBT for determination of the intracellular distribution of guanase in human hepatocytes. In the hepatocytes, the reaction products were seen to be concentrated in the nucleus, in mitochondria, cisternae of the smooth and/or rough-surfaced endoplasmic reticulum, and lysosomes. The precise locations of the reaction product in the cisternae of the nuclear envelope, chromosomes, and nucleus could not be determined. However, the reaction products in the mitochondria were clearly seen to be located in the spaces of cristae. This information of the intracellular distribution of guanase in normal hepatocytes will be useful in determining the physiological role of this enzyme and in further studies on diseased hepatocytes including those in non-A non-B hepatitis.

Non-A, non-B hepatitis after open-heart surgery in Stockholm: declining incidence after introduction of restrictions for blood donations due to the human immunodeficiency virus

In 1979 the incidence of non-A, non-B (NANB) posttransfusion hepatitis (PTH) in Stockholm was 19%. After the discovery of HIV the Swedish Board of Health put forward new regulations for blood donations and since 1985 has enforced testing for HIV on all blood units. To find out if these measures have had any impact on the incidence of NANB PTH, 316 patients transfused during open-heart surgery from December 1985 to November 1986 were followed prospectively. PTH due to the NANB agent(s) developed in 4.4% (14/316). A significantly higher mean number of blood units had been given to patients undergoing coronary artery bypass surgery in whom NANB PTH developed than in those who did not develop the infection. The mean number of blood units transfused during open-heart surgery in Stockholm had decreased from 16 in 1979 to 10 in 1985-1986. The number of NANB PTH cases/1,000 blood units transfused declined from 12 to 4 during the same period. Thus, both the reduced number of blood units given during open-heart surgery and the new restrictions for blood donors seem to have been effective in reducing the risk for NANB PTH in Stockholm during the 1980s.