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Biomedical subjects

K Sazama

Publications and source records attributed to K Sazama.

At least 19 recordsLinked to original sources
PubMed1998

Monitoring heparin therapy: APTT results from partial- vs full-draw tubes.

Results of the activated partial thromboplastin time (APTT) test can be influenced by biologic, preanalytic, and analytic variables. When a patient is being treated with unfractionated heparin, the correct interpretation of the APTT test result is essential. Laboratories should evaluate all variables influencing this result, particularly when determining the "therapeutic" range for heparin treatment. This study compared the APTT results assayed on specimens drawn into 2 different types of evacuated blood collection tubes. A statistically significant difference was seen in the results when the APTT was outside the reference interval, including results in the therapeutic range for unfractionated heparin. When the therapeutic range is determined by the laboratory, the evacuated blood collection tube system must be standardized.

Anticoagulants↗
PubMed1998

Interactions between science, government and media on selection and testing of donors.

The international media attention to "bad blood" has fueled governmental action in countries around the world. Donor selection criteria continue to expand, focusing most recently on the possibility of exclusion due to intranasal cocaine use and, in the US, due to incarceration for more than 72 hours. As newer methods of testing evolve, more deferrals will occur due to improved testing. An emerging area of concern is the non-standardized notification of donors who are ineligible to donate and lack of a centralized listing of such deferred donors. Because of the consequences to recipients, improvements in both donor questioning and testing are necessary. Further studies are needed to understand and improve these processes.

AIDS Serodiagnosis↗
PubMed1997

Practical issues in informed consent for transfusion.

Because patients are knowledgeable and have concerns about the risks of proposed therapies, including transfusion, and are interested in possible alternatives, they are becoming more involved in their own health care. Legal decisions support the patient's interest. Since 1996, the Joint Commission on Accreditation of Healthcare Organizations has specifically required that institutions document informed consent for transfusion. These regulations emphasize the need to establish a practical approach to achieving this process so that physicians and institutions appropriately inform patients and adequately document the patient's choice.

Blood Transfusion↗
PubMed1996

Current good manufacturing practices for transfusion medicine.

Transfusion medicine is most tightly controlled in the US by CGMPs that are written as regulations, guidances, and quality management documents. Because the US regulatory scheme requires that each unit of human blood donated for transfusion (and other purposes) be documented from the moment of donor registration until the last component of that donation is finally disposed of, there is precious little that remains solely within the discretion of the treating physician who orders transfusions for her or his patients. An additional complication for transfusion medicine specialists is that the search for the requirements must extend to all possible areas of information, including the possibly unexpected source within the private sector.

Blood Banks↗
PubMed1994

Evidence that use of a second-generation hepatitis C antibody assay prevents additional cases of transfusion-transmitted hepatitis.

The aim of this study was to determine if using hepatitis C antibody (anti-HCV) enzyme immunoassay version 2.0 (EIA2) in addition to version 1.0 (EIA1) increased the safety of the blood supply. Blood non-reactive by anti-HCV EIA1 was transfused in 1990-92. Stored samples from 40098 units, donated prior to 13 March 1992 were later tested by EIA2. For donor units reactive for anti-HCV by EIA2, a recombinant immunoblot assay (RIBA2) was also carried out. In 63 cases, recipients of transfusions which were EIA2 negative or EIA2 reactive were tested for anti-HCV and elevated alanine aminotransferase (ALT) levels 9-12 months after transfusion; pretransfusion anti-HCV status of recipients was unknown. Among these multitransfused patients receiving units that were negative by both EIA1 and EIA2, 1/26 (4%) had anti-HCV. Among transfusion recipients of units negative by EIA1, but who received at least one unit reactive by EIA2, 4/37 recipients (11%) were anti-HCV reactive (P = 0.59). For the recipients of EIA2 reactive blood, when the donor unit was RIBA2 non-reactive, 0/23 recipients were reactive by anti-HCV. Among the recipients of a RIBA2 indeterminate unit, 1/10 recipients had anti-HCV, but for patients who received at least one RIBA2 reactive unit, 3/4 recipients had anti-HCV (P = 0.03). Hence, second-generation anti-HCV testing detected additional units capable of transmitting hepatitis C that were not detected by first-generation testing. However, RIBA2 is a more specific method than EIA2 for determining units capable of transmitting HCV.

Aged↗
PubMed1994

Bacteria in blood for transfusion. A review.

OBJECTIVE: To summarize reports of bacterial contamination of blood components for transfusion during this century, considering implicated microorganisms and patient outcomes, with identification and discussion of recommended methods to reduce or eliminate this problem. DATA SOURCES: Articles published in the English-language literature from which summary tables of all reported bacterial infections were prepared by collating published case reports, including fatalities, emphasizing recent concerns about Yersinia contamination. STUDY SELECTION: All case reports and related review articles relevant to issues about bacteria implicated in transfusion-associated sepsis were included. DATA EXTRACTION: The author personally extracted all data. DATA SYNTHESIS: With the exception of Yersinia species and Campylobacter jejuni in red blood cells and Salmonella heidelburg in platelets, the majority of bacteria implicated continue to be those found in the environment and as normal skin flora. Existing measures to identify contaminated components before transfusing them are inadequate. Manufacturing efforts to sterilize these components by various methods may result in greater benefit than those directed toward preventing contamination during collections. CONCLUSIONS: Bacterial contamination remains a problem for transfusion medicine. Active research should continue to focus on elimination of contaminants by filtration, chemical additives, or irradiation, as well as innovative measures to detect and exclude infected units from transfusion.

Bacteria↗
PubMed1993

Evidence of hepatitis in patients receiving transfusions of blood components containing antibody to hepatitis C.

When hepatitis C virus antibody (anti-HCV) enzyme immunoassay (EIA1) testing became available in 1990, we tested samples from previously transfused blood units, traced the recipients of reactive units, and evaluated the recipients for HCV infection during the 12 months after transfusion. Ten of 42 recipients of EIA1-reactive blood were anti-HCV reactive on follow-up by EIA1 and 12 were reactive by a second-generation assay (EIA2). Reverse transcriptase-polymerase chain reaction (RT-PCR) detected HCV RNA in 5 seronegative recipients. In all, 17 of 42 recipients (40%) of EIA1-reactive blood had evidence of HCV infection. In comparison, 54 surgery patients, who received either no transfusion or autologous EIA1-nonreactive blood, remained EIA1 nonreactive and RT-PCR negative for 1 year; 1 patient (1.8%) became EIA2 reactive (P < or = .01). Of the recipients of anti-HVC reactive blood transfusions (reactive by both EIA1 and a supplemental 4-antigen strip immunoblot assay [RIBA2]), 14 (93%) of the recipients had evidence of HCV infection compared with only 3 of 27 recipients (11%) of EIA1-reactive, RIBA2-nonreactive blood (P < or = .01). Thus, blood components reactive for anti-HCV EIA1 may have transmitted HCV up to 40% of the time, but blood components found reactive by both EIA1 and RIBA2 may transmit HCV with a frequency of greater than 90%.

Adult↗
PubMed1993

Hepatitis C virus in blood samples from volunteer donors.

The specificities of four assays for hepatitis C virus (HCV) were compared by using units from volunteer blood donors. Upon Food and Drug Administration licensure of the first immunoassay for anti-HCV, EIA-1, units previously deemed acceptable for transfusion and all subsequent blood donations were screened. EIA-1 repeat-reactive (RR) units were tested for HCV by a second-generation enzyme-linked immunoassay (EIA-2) and by a four-antigen recombinant immunoblot assay (RIBA II) and for HCV RNA by reverse transcriptase polymerase chain reaction. All HCV RNA-positive samples were reactive by both RIBA II and EIA-2. All RIBA II-reactive sera were EIA-2 RR. In EIA-1, 0.45% of the prescreened units and 0.59% of the prospectively screened donors were RR. Of these, 52.5 and 54%, respectively, were EIA-2 RR, 71.4 and 69% of the EIA-2 RR units were reactive on RIBA II, and 93 and 88% of the RIBA II-reactive samples were HCV RNA positive. When the sample/cutoff ratio for EIA-2 was greater than 5, 91% of the samples were RIBA II reactive and 82% of the samples were HCV RNA positive. None of EIA-2 RR units with a sample/cutoff ratio of < 5 was RIBA II reactive or HCV RNA positive. In conclusion, RIBA II and RT PCR results are highly concordant. A sample/cutoff ratio of > 5 in EIA-2 is a good discriminator for the likelihood of a true HCV infection on the basis of RT PCR and RIBA II assays.

Base Sequence↗
PubMed1992

Detection of antibodies to human immunodeficiency virus type 2 (HIV-2) in blood donor sera using United States assay methods for anti-HIV type 1.

Twelve serum samples from French blood donors that were uniformly reactive in tests for antibody to human immunodeficiency virus type 2 (anti-HIV-2) also were reactive in 92 to 100 percent of tests with three anti-HIV type 1 (anti-HIV-1) enzyme-linked immunoassays currently in widespread use for donor screening in the United States. Supplemental tests for anti-HIV-1 on these anti-HIV-2-reactive samples differed in their responses. All samples reacted in a licensed anti-HIV-1 Western blot, but there was an atypical band near the p41 position, which could be a clue to the fact that this result was a cross-reaction with anti-HIV-2. A recombinant immunoblot gave an indeterminate result for anti-HIV-1 in all 12 samples. A local immunofluorescence assay for anti-HIV-1 reacted with 92 percent of the samples, but a commercial one detected only 58 percent.

Antibodies, Viral↗
PubMed1992

Detection of antibody to immunodeficiency viruses by dot immunobinding assay.

The dot immunobinding assay (DIA), a modified enzyme immunoassay (EIA), has been demonstrated to be a highly sensitive and specific assay for the detection of antibody to a number of viruses. Different laboratory procedures are available for detecting antibody to the immunodeficiency viruses; however, these procedures require a certain amount of sophisticated equipment and trained personnel. Further, commercial kits for detecting antibody to human immunodeficiency virus, as now available, are not easy to use in the nonlaboratory setting. The DIA, as described herein, may be formatted to test up to 30 serum samples and is designed to be used in the absence of laboratory equipment. To determine the effectiveness of the DIA as a test kit for the detection of HIV and human T-cell leukemia virus type I (HTLV-I) antibodies, the kit was compared with commercial EIA and Western blot (WB; immunoblot) kits. Testing approximately 1,000 human serum samples for HIV antibody by DIA and EIA revealed a total agreement of 98.1%, a specificity of 99.0%, and a sensitivity of 95.9%. For 804 serum samples tested (200 were tested independently in two laboratories), eight results were discrepant: four DIA negatives which were EIA borderline positive and four DIA positives which were EIA negative. Testing the eight discrepant sera by immunofluorescence assay and WB resulted in their being either negative or indeterminate. The four DIA positives were indeterminate by WB. Close agreement was obtained when the remaining sera were compared by DIA, EIA, and WB. Of interest was finding that the DIA results compared favorably with those obtained by WB. Twenty-six suspect HTLV-I-positive serum samples tested by DIA also gave results comparable to those obtained by EIA and WB.

Blotting, Western↗
PubMed1992

Seroepidemiology of viral infections among intravenous drug users in northern California.

Intravenous drug users are frequently exposed to parenterally transmitted viral infections, and these infections can spread to the general population through sexual activity. We investigated the prevalence of serologic markers for human immunodeficiency virus type 1 (HIV-1), human T-cell lymphotropic virus type I/II (HTLV-I/II), hepatitis B virus (HBV), and hepatitis C virus (HCV) in intravenous drug users and their sexual contacts. Of 585 drug users from northern California tested for these serologic markers, 72% were reactive for the antibody to HCV, 71% for the antibody to hepatitis B core antigen, 12% for HTLV-I/II antibodies, and 1% for the HIV-1 antibody. The prevalence of serologic markers for these four viruses correlated with the duration of intravenous drug use, the ethnic group, and the drug of choice. More than 85% of subjects infected with either HCV or HBV were coinfected with the other virus. All persons reactive to HTLV-I/II antibodies had antibodies for either HBV or HCV. Of 81 sexual contacts tested, 17% had evidence of HBV infection while only 6% were reactive for HTLV-I/II antibodies and 4% for the antibody to HCV. None of this group was infected with HIV-1. We conclude that HTLV-I/II and HCV are inefficiently transmitted to sexual contacts while HBV is spread more readily. Programs designed to discourage the sharing of drug paraphernalia, such as needle and syringe exchanges, should decrease the risk of parenterally spread viral infections in intravenous drug users and thus slow the spread of these infections to the general population.

Adult↗
PubMed1990

Reports of 355 transfusion-associated deaths: 1976 through 1985.

From 1976 through 1985, the United States Food and Drug Administration received reports of 355 fatalities associated with transfusion, 99 of which were excluded from further review because they were unrelated to transfusion or involved hepatitis or acquired immune deficiency syndrome. Of the remaining 256 reported deaths, 51 percent resulted from acute hemolysis following the transfusion of ABO-incompatible products. These deaths were due primarily to managerial, not clerical, errors. Other causes of death (in order of frequency of report) included acute pulmonary injury (15%), bacterial contamination of product (10%), delayed hemolysis (10%), damaged product (3%), and graft-versus-host disease (0.4%). Management systems for transfusion facilities should be created or revised to include the specific identification of personnel eligible to administer transfusions to provide written guidance and appropriate training (including recognition and management of errors), and to implement measures that target safe transfusion practices. Continued research into acute pulmonary injury, the immunologic hazards of transfusion, and the prevention of bacterial contamination of blood components is necessary.

Acute Disease↗