云南省昆明地区1993～1995年献血员HIV抗体检测情况分析

自１９９３～１９９５年对昆明地区献血员进行了ＨＩＶ抗体检测，３年中共检测１０２３９２人次，６９２１５人。初筛ＨＩＶ抗体阳性者１６人，确认ＨＩＶ感染者４人。４例均为男性，经性途径而感染，都为外省籍民工。ＨＩＶ血清抗体检出率随着时间的推移而增加，检出频率也越来越快。     

Look-Back of Anti-HCV ELISA-Positive, HCV-RNA PCR-Negative Donors and Recipients of Their Blood Products

Background and objectives: To establish the infectivity of anti-HCV ELISA-positive, but cDNA-PCR-negative blood components transfused before the introduction of routine anti-HCV blood donor screening, we enrolled recipients of such blood products in a look-back programme. Materials and methods: The blood components were donated by (A) RIBA?-2-indeterminate and cDNA-PCR-negative donors, and (B) RIBA-2 and cDNA-PCR-negative donors. The look-back comprised 214 blood products from group A donors and 278 from group B. Results: Of 211 recipients of group A components, 66 (31.3%) were available for testing. All other recipients could not be traced, had died, or refused collaboration. Of these 66, 3 patients had independent risk factors for HCV infection and were excluded. All remaining 63 recipients were anti-HCV ELISA-negative. Of 274 recipients of group B components, 84 (30.7%) were available for testing. All others could not be traced, had died, or refused collaboration. Of these 84, six patients had an independent risk factor for HCV infection and were excluded. All remaining 78 recipients were anti-HCV ELISA-negative. None of the recipients of blood products from previous donations of anti-HCV ELISA-positive, cDNA-PCR-negative, and RIBA-2-indeterminate or negative donors were HCV-infected. Conclusions: Donors and patients with such reactivities in anti-HCV ELISA, RIBA-2, and cDNA-PCR can be assured that they are not infected with HCV. The donors involved can re-enter the donor pool, provided that future donations are anti-HCV ELISA-negative.     

The Prevalence of Hepatitis B Surface Antigen and Its Antibody in Blood Donors and High Risk Groups in Iran

The prevalence of HBsAg and anti-HBs among voluntary blood donors, professional blood donors, INBTS laboratory staff, haemophiliacs and the patients and medical personnel of three haemodialysis centres was compared. The 3.4% incidence of HBsAg found among 168,890 voluntary donors was significantly less than the 8.4% found among 378 professional blood donors. The prevalence of HBsAg was higher in male than in female donors, and also higher in single than in married donors. Prevalence of HBsAg was unrelated to ABO-Rh blood group but was related to age. Anti-HBs was found in 30% of voluntary blood donors, 67% of professional donors, 68% of haemodialysis patients, 39% of haemodialysis staff, 86% of haemophiliacs and in only 4.8% of HBsAg carriers. Subtyping of HBsAg found in 100 voluntary donors showed 65 were ay; 5 ad; 10 ad + ay and 20 were untypable.     

The Prevalence of Celiac Disease in Blood Donors in Iceland

Background Prospective epidemiological studies based on serological methods have shown that celiac disease is more common than previously thought. The aim of this study was to evaluate the prevalence of celiac disease among apparently healthy blood donors in Iceland. Methods Plasma samples were obtained from 813 apparently healthy blood donors at the FSA Hospital Blood Bank in Akureyri, Iceland, between December 2004 and January 2007 and screened for human tissue transglutaminase IgA antibodies. Positive samples were retested and, if the test was again positive, the subject was referred to a gastroenterologist for clinical examination and a duodenoscopy with mucosal biopsies. Results Six subjects tested positive for tissue transglutaminase. The prevalence of biopsy-confirmed celiac disease, according to modified Marsh classification, among apparently healthy blood donors in Iceland was found to be 1:136 (0.74%, 95% confidence interval 1/667–1/75, 0.15–1.33%). Conclusion Prevalence of celiac disease in Iceland is similar to what has been reported in many other countries.     

HCV-Infection in Blood Donors: Association between Anti-HCV Core IgM Antibodies and Serum HCV RNA

Among 47 blood donors tested positive with HCV EIA 2.0 Abbott, 27 (57.4%) also reacted with four ‘third-generation’ EIAs. The presence of anti-HCV antibodies was confirmed with 3 different immunoblot assays in 16 of 27 sera (34.0%) while 10 samples (21.3%) had indeterminate profile with antibodies usually directed against structural core antigen. Anti-HCV core IgM response was found in 12 of 47 sera (25.5%) and HCV viremia detected by the polymerase chain reaction (PCR) procedure was observed in 15 samples (31.9%). A comparative study of the different markers confirmed a good correlation between a strong antibody response in EIAs and immunoblot assays and the presence of HCV RNA in the serum; only 2 immunoblot indeterminate samples were PCR positive. An association was observed between IgM antibodies against ‘core’ epitopes and HCV RNA carriage: all IgM-positive sera were found positive by PCR. However, the direct detection of viral genome remains the best method for identifiying HCV carriers in the blood donor population.     

Follow-Up Studies of Healthy Blood Donors. Anti-HBs Antibody Carriers

Abstract. 10 healthy blood donors persistently seropositive for anti-HBs and without a history of clinically overt viral hepatitis were observed for periods of time ranging from 46 to 57 months. Physical examinations and biochemical liver function tests were normal in all cases. Immunologic studies of their immune response to hepatitis B virus antigens are suggestive for a late period of convalescence from clinically inapparent hepatitis B.     

Prevalence of Hepatitis C Virus Antibodies in Italian Blood Donors

11,117 blood donors from 24 blood transfusion services evenly distributed throughout the various Italian regions were tested for the presence of hepatitis C virus (HCV) antibodies in the serum and serum alanine aminotransferase (ALT) level. The results are as follows: (1) anti-HCV seroprevalence in Italy was 0.87% with a difference between Northern and Southern regions (0.68 vs. 1.37%) and between younger and older subjects (0.62 vs. 1.21%); (2) prevalence of elevated ALT levels was 4.74% without a North-South effect (except than for markedly elevated ALT levels); (3) anti-HCV seroprevalence was higher in subjects with elevated ALT (5.0%), with a North-South effect (2.2 vs. 9.9%) and particularly high (19.2%) in subjects with markedly elevated ALT; (4) ALT levels were elevated in 26.2% of anti-HCV positive subjects, with a North-South effect (14 vs. 40.5%).     

HIV Antibody Screening and Confirmatory Testing of Italian Blood Donors

During the first year (1986) of blood donor screening for antibody to HIV, 201,750 subjects were tested in 40 blood banks of Lombardia (Italy). All sera repeatedly positive by ELISA were submitted to our reference center for confirmation by Western blot (WB). Only 40 (0.02%) of 286 repeatedly reactive donors were positive by WB, whereas another 45 (0.022%) gave atypical antibody reactivities on WB, mainly directed against HIV core proteins. Of the 16 donors with inconclusive WB results followed for 4-12 months, 3 developed a full-blown antibody response, 5 maintained the anti-core reactivity throughout the follow-up period, and 8 lost all reactivities. The use of recombinant env and core antigen ELISAs seems to decrease the proportion of sera with inconclusive WB reactions, and to identify as true positive all seroconverting donors in advance of the WB test. The large majority (35 out of 40) of WB-positive donors and all seroconverters for antibody to HIV admitted to belong to a group at risk for AIDS. Among the 19 first-time donors with HIV infection, we found 3 subjects with serological evidence of LAV-2 infection. We describe also the diagnostic and ethical issues when a donor notification policy is based on WB confirmatory procedures.     

Screening Blood Donors for High Titre Antibody to Herpes Varicella-Zoster

As a method of increasing supplies of varicella-zoster immunoglobulin, semi-automated screening of blood donors for high titre complement-fixing antibody was initiated. This was compared with the previously used method of donor selection based on a history of varicella or zoster in the past 6 months. About one-third of the "history" donors had titres of greater than or equal to 1 in 64 and generally these levels declined rapidly. In contrast, although only 1.1% of donors in random screening had antibody titres greater than or equal to 1 in 64, these levels usually remained high during repeated donation, enabling the production of pools entirely composed of high titre plasma packs.     

Prevalence of Hepatitis B Surface Antigen in Northern Nigerian Blood Donors

1,860 serum samples of blood donors from northern Nigeria were tested for the presence of the hepatitis B surface antigen. 8.9% of them were found to be positive. Significant differences in frequency were observed amongst various ethnic groups as well as ABO blood groups.     

Seroindeterminate HTLV-1 Prevalence and Characteristics in Blood Donors in Taiwan

Human T-cell leukemia virus type 1 (HTLV-1) is commonly accepted as the cause of adult T-cell leukemia and tropical spastic paraparesis/HTLV-1-associated myelopathy. Screening of blood donors for HTLV-1 and HTLV-2 was implemented in Taiwan in February 1996. From February 1996 to December 1998, we investigated the seroprevalence of HTLV-1 in all unpaid blood donors in Taiwan. Of 2,578,238 donors in all 6 blood centers, 1793 (0.06%) were seropositive for HTLV-1, and 605 (0.023%) were indeterminate for HTLV-1. Among these indeterminate donors, 359 (59.3%) were male. The most common HTLV-1-indeterminate pattern by Western blot in our study was GD21 alone (34.6%) followed by p24 alone (7.8%), p53 alone (6.5%), and gp46 + GD21 (6.0%). That GD21 pattern was found in 59.6% of indeterminate results in this study suggested that the majority of nonspecific enzyme immunoassay reactions were probably precipitated by viral envelop glycoprotein GD21.     

Comparison of Solid-Phase Antibody Screening Tests with Pooled Red Cells in Blood Donors

Solid-phase systems are very sensitive for detection of erythrocyte alloantibodies in serum and suitable for large scale donor screening. Serum samples of 10,008 blood donors were screened by three solid-phase tests (Capture R Ready Screen, Solidscreen II, and Solidscreen II-Donor) with pooled red cells derived from two donors. The prevalence of antierythrocyte IgG and IgM antibodies in donor sera was 0.56% (IgG antibodies: 0.42%). The test efficiency for IgG antibodies was 1.40 with Capture R Ready Screen (test sensitivity 97.6%, test specificity 99.39%), 1.78 with Solidscreen II (95.1, 99.88%), and 1.95 with Solidscreen II-Donor (92.7, 99.98%). The IgG antibody titers differed significantly between all tests including a gel matrix test: Capture R > ID-Gel > Solidscreen II > Solidscreen II-Donor. Previously characterized antibodies that were not detected after long-term follow-up by any of the three solid-phase tests had a prevalence of 0.10%. All three solid-phase tests detected the alloantibodies, which were of higher titers and considered clinically relevant in blood components. The significant difference in antibody titers between the tests was not matched by a similar variance in the detection of donors with antibodies. Even with sensitive solid-phase tests, many antibodies may not be detected after long-term follow-up.     

High Prevalence of Increased Osmotic Fragility of Red Blood Cells among Norwegian Blood Donors

Increased osmotic fragility of red blood cells was found in 9 out of 1008 Norwegian blood donors. In addition, increased osmotic fragility was found in 3 out of 23 first grade relatives and in 1 out of 4 spouses of individuals with the same condition. Finally, there was a positive correlation between increased osmotic fragility and morphological signs of spherocytosis (P < 0.05). No definite conclusions with respect to underlying mechanism(s) for this high prevalence of non-symptomatic increased osmotic fragility can be offered, but very mild hereditary spherocytosis, environmental factors and even a normal variant, never associated with haemolysis, may have contributed. Furthermore, until more specific and sensitive laboratory techniques have been introduced, a proper distinction between these 3 conditions cannot be made.