The direct antiglobulin test in a hospital setting.

To evaluate the current use of the DAT in our hospital,we reviewed the charts of all patients who had a DAT performed in our laboratory. The collected data included DAT results and a previously completed laboratory evaluation of suspected hemolytic anemia. Four hundred sixty-three DATs were performed in our laboratory from April 1999 to October 2001. The DAT was negative in 434 (93.7%) cases and positive in 29 (6.3%) cases. A complete laboratory evaluation of suspected hemolytic anemia was seen in 179 (38.7%) cases. The incidence of a positive DAT was higher in the group of patients with > 2 signs of hemolysis (4/34 cases; 11.8%) than in the group of patients with

Autoanti-D in a patient after cladribine treatment for lymphoplasmocytic lymphoma.

We report the case of a 62-year-old woman who developed an autoanti-D after cladribine treatment. In May 2000, the patient underwent splenectomy for a stage IV-B lymphoplasmocytic lymphoma. She was transfused with ABO- and Rh(D)-matched blood. A month later, she received chemotherapy with cladribine. In February 2001, blood grouping showed her to be AB, D+ and the direct antiglobulin test was positive for IgG. An autoanti-D was identified in the eluate. Genotypic analysis confirmed the Rh phenotype of the patient as ccDEe. No hemolysis was evident, as judged by the absence of anemia, a bilirubin of 15.7 micromol/L, and lactic dehydrogenase of 412 IU/L. When an anti-D is identified in a D+ blood recipient, a passive transfer of anti-D, and an alloimmunization in a recipient with a weak D phenotype, should be ruled out. Finally, as in our case, an autoantibody is an additional possibility.

One thousand seventy antibodies detected only by a 2-stage papain test: wanted and unwanted positive reactions.

Despite the wide use of the antibody detection test for unexpected antibodies, controversy still remains regarding the use of enzyme-treated red blood cells. Over a 6-year period, 72,573 samples from 49,863 patients submitted for pretransfusion compatibility testing were examined for unexpected antibodies. The antibody detection tests included a low-ionic-strength solution (LISS) indirect antiglobulin test and a two-stage papain (2SP) test. One thousand and seventy of the 2267 (47%) antibodies tested by 2SP were reactive only by the 2SP test. Overall, the 2SP test detected only 0.6% of antibodies considered to be clinically significant (10 examples of anti-c and 2 examples of anti-e). The slight additional safety provided by detection of clinically-significant antibodies is overshadowed by the high number of clinically-insignificant antibodies detected by the 2SP test.

High rate of infectivity and liver disease in blood donors with antibodies to hepatitis C virus.

OBJECTIVE: To determine the epidemiologic, clinical, serologic, and histologic importance of antibodies to hepatitis C virus (anti-HCV) in blood donors. DESIGN: Cross-sectional identification and prospective evaluation of seropositive donors; retrospective assessment of infectivity; and nested case-control study for risk factors. SETTING: Liver unit of a referral-based university hospital. SUBJECTS: Of 30,231 consecutive donors, 368 (1.2%) were found to be anti-HCV-reactive by enzyme-linked immunosorbent assay (ELISA). Two hundred and fifty-four of these 368 donors were evaluated for risk factors by comparison with 284 age- and sex-matched controls. Eighty-six spouses of seropositive donors were also evaluated. MEASUREMENTS AND MAIN RESULTS: Twenty-four percent of the seropositive donors had a history of percutaneous exposure to blood. This rate increased to 45% when only those donors confirmed to be anti-HCV positive by a second-generation recombinant immunoblot assay (RIBA-2) were considered. A family history of liver disease (odds ratio, 2.8; 95% Cl, 1.6 to 4.8), previous blood transfusion (odds ratio, 6.1; 95% Cl, 3 to 12.5), and a history of tattooing or intravenous drug abuse (odds ratio, 8.4; 95% Cl, 2.3 to 31) were associated with anti-HCV seropositivity. An elevated alanine aminotransferase (ALT) level was found in 58% of the seropositive donors. Of the 150 donors tested, 104 (69%; Cl, 62% to 77%) were confirmed by RIBA-2 to be anti-HCV positive. Of the 105 donors who had a biopsy, 16% had normal histologic findings, 11% had minimal changes, 21% had chronic persistent hepatitis, 45% had chronic active hepatitis, and 7% had active cirrhosis. All 77 donors with RIBA-2-confirmed seropositivity had histologic abnormalities. Of 43 donors evaluated in an infectivity study, 82% were implicated in previous HCV transmission. Only 2.3% of the spouses were anti-HCV positive. The ELISA, RIBA-2, and ALT results correlated with infectivity and abnormal histologic findings. CONCLUSIONS: In our geographic area, almost 70% of donors who are anti-HCV positive by ELISA are confirmed to be positive by RIBA-2; most of these donors appear to be chronic carriers of HCV and have substantial liver disease.

Evaluation of antibodies to hepatitis C virus in a study of transfusion-associated hepatitis.

BACKGROUND: The hepatitis C virus (HCV) is now known to be the chief cause of transfusion-associated non-A, non-B hepatitis, but the prevalence of HCV among blood donors and the frequency of transmission by blood transfusion are unknown. METHODS: To assess the sensitivity and specificity of a test for antibody to HCV, we tested serum samples from participants in a large study of transfusion-associated hepatitis. Samples were obtained prospectively from consecutive adults undergoing open-heart surgery in Spain, but were tested retrospectively, after the antibody enzyme immunoassay for anti-HCV became available. RESULTS: Of 280 transfusion recipients given a total of 1109 units of blood, 27 (9.6 percent) had transfusion-associated non-A, non-B hepatitis (mean follow-up, 52 weeks) and 24 of the 27 seroconverted to anti-HCV-positive, whereas only 2 (0.8 percent) of the remaining transfusion recipients seroconverted. Among the 1044 donor specimens available for testing, 16 (1.5 percent) had anti-HCV antibody. Only 1 additional seropositive donor was found when 44 implicated donors who had been seronegative were retested 9 to 12 months later. Of the 16 recipients of anti-HCV-positive blood, 14 (88 percent) had transfusion-associated hepatitis and seroconverted to anti-HCV-positive. The remaining two recipients had neither hepatitis nor anti-HCV antibody. Among 25 patients with non-A, non-B hepatitis for whom all transfused blood was tested, 14 had received blood positive for anti-HCV. CONCLUSIONS: About 90 percent of blood donors with antibody to HCV have infectious virus in their blood. The screening of blood donors for anti-HCV antibody should prevent about half the cases of transfusion-associated hepatitis, but the donors with infectious virus who are anti-HCV-negative may remain seronegative for prolonged periods.