Multiple unconfirmed-reactive screening tests for viral antibodies among blood donors

BACKGROUND: In December 1991, the United States Food and Drug Administration received reports of blood donations with unconfirmed reactivity on screening tests for antibodies to human immunodeficiency virus, human T-lymphotropic virus type I, and hepatitis C virus (HCV). Of 91 donors with these test results, 57 (63%) reported a recent influenza vaccination. STUDY DESIGN AND METHODS: To determine the extent of unconfirmed reactivity, the time at which it began, and its association or nonassociation with specific manufacturers' tests, a nationwide survey of blood centers was conducted. A case-donation was defined as a blood donation that was repeatedly reactive, but not confirmed positive, on at least two of the three tests from May 1990 through December 1991. RESULTS: Among 14 million donations screened by 110 centers, 582 case-donations were identified. An increase in case- donations was evident in the fall of 1990 (2.8/100,000 donations). In 1991, rates increased from 0.9 per 100,000 donations in the first quarter to 1.3, 3.2, and 19.7 in subsequent quarters. A significantly higher rate of case-donations was observed among donations tested with one of the two available anti-HCV screening tests (8.0 vs. 1.2/100,000 donations; risk ratio = 6.8; 95% CI = 5.4-8.5). CONCLUSION: Although unconfirmed reactivity on multiple screening tests appeared to be seasonal, its documentation prior to the availability of influenza vaccine in 1991 and higher rates among donations tested with one manufacturer's anti-HCV test indicated that test-specific factors were also involved.     

Lysis of human fibroblast colony-forming cells and endothelial cells by monoclonal antibody (6-19) and complement

The murine IgG2a monoclonal antibody 6-19 binds to a wide variety of nonhematopoietic cells including human marrow-derived stromal cells but does not bind to marrow or peripheral blood cells. We studied the effects of this antibody and rabbit complement on marrow cells. Fibroblast colonies were eliminated from light density marrow cells by a single incubation with monoclonal antibody 6-19 and complement. The growth and composition of granulocytic and erythroid colonies were unaffected. Specific complement mediated cytotoxicity of the antibody was confirmed on passaged human fibroblasts derived from marrow (more than 99.6% of fibroblasts are killed by a single treatment). Similar results were obtained with human umbilical cord endothelial cells. In addition, such treatment abolished the initiation of Dexter culture stroma. Incubation of bone marrow cell suspensions with this antibody and complement will allow the study of stroma-free marrow cells in long- term liquid cultures.     

Second malignancies after treatment for laparotomy staged IA-IIIB Hodgkin's disease: long-term analysis of risk factors and outcome

The survival of patients with Hodgkin's disease has dramatically improved over the past 30 years because of advances in treatment. However, concern for the risk of long-term complications has resulted in a number of trials to evaluate reduction of therapy. The consequences of these trials on recurrence, development of long-term complications, and survival remain unknown. One major consequence of successful treatment of Hodgkin's disease is the development of second malignant neoplasms. We sought to determine the factors most important for development of second tumors in pathologically staged and treated Hodgkin's disease patients followed for long intervals to provide background information for future clinical trials and guidelines for routine patient follow-up. Between April 1969 and December 1988, 794 patients with laparotomy staged (PS) IA-IIIB Hodgkin's disease were treated with radiation therapy (RT) alone or combined radiation therapy and chemotherapy (CT). There were 8,500 person-years of follow-up (average of 10.7 person-years per patient). Age and gender-specific incidence rates were multiplied by corresponding person-years of observation to obtain expected numbers of events. Observed to expected results were calculated by type of treatment, age at treatment, sex, and time after Hodgkin's disease. Absolute (excess) risk was expressed as number of excess cases per 10,000 person-years. Seventy-two patients have developed a second malignant neoplasm. Eight patients developed acute leukemia, 10 had non-Hodgkin's lymphoma (NHL), and 53 patients developed solid tumors at a median time of 5 years, 7.25 years, and 12.2 years, respectively, after Hodgkin's disease. One patient developed multiple myeloma 16.5 years after Hodgkin's disease. The relative risk (RR) of developing a second malignancy was 5.6. The absolute excess risk per 10,000 person-years (AR) of developing a second malignancy was 69.6 (7.0% excess risk per person per decade of follow-up). The highest RR occurred for the development of leukemia (RR = 66.2), however because of the low expected risk, the AR was only 9.3. The RR of solid tumors after Hodgkin's disease was lower (4.7); however, the AR was greater (49) than for acute leukemia. Among the solid tumors, breast, gastrointestinal, lung, and soft tissue cancers had the highest absolute excess risks. The risk for developing breast cancer after Hodgkin's disease was greatest in women who were under the age of 25 at treatment. The most significant risk factor for the development of both leukemia and solid tumors was the combined use of radiation therapy and chemotherapy. The RR following RT alone was 4.1 (AR = 51.1); for RT + CT (initially or at relapse) the RR was 9.75 (P < 0.05, nonoverlapping confidence limits, AR = 123.9). Survival following development of a second malignancy was poor in patients with leukemia, gastrointestinal tumors, lung cancer, and sarcoma. Survival from other malignancies including NHL and breast cancer was more encouraging. Second malignant neoplasms are a major cause of late morbidity and mortality following treatment for Hodgkin's disease. The most significant risk factor for the development of second tumors is the extent of treatment for Hodgkin's disease. Recommendations are presented for both prevention and early detection of these tumors.     

The treatment of malignant histiocytosis

Twenty-four consecutive cases of malignant histiocytosis (MH) treated at Stanford Medical Center between 1973 and 1983 have been reviewed. Most patients presented with systemic symptoms (91%) and advanced disease (stage IV, 80%). Multiple organ involvement was common. In six cases, pathologic tissue was further characterized by frozen section immune histochemistry, using a panel of monoclonal antibodies known to react with monocytes and macrophages, as well as a variety of hematopoietic cells. One case expressed a mature monocyte/macrophage phenotype; three cases were considered null cell or primitive lesions; and two cases were identified as probable T cell lymphomas. Seven patients underwent splenectomy. Two patients died prior to any treatment. Twenty-two patients were treated with CHOP (cyclophosphamide, Adriamycin, vincristine, prednisone) +/- bleomycin (B), +/- midcycle high-dose methotrexate (HD-MTX) with leucovorin rescue. Seven patients received prophylactic intrathecal MTX. Of 22 evaluable patients, there was a 68% complete response rate (CR), a 23% partial response rate (PR), and a 9% no response rate (NR). Median duration of CR was 30+ months; median duration of PR was 2.4 months. Median survival for patients attaining a CR has not been reached v 3 months for the PR and NR groups. For all 24 patients, median survival was 2 years, with a 5-year actuarial survival of 40%. Multivariate analysis revealed that a platelet count less than 150,000 (P Cox = .005) and the dose of drug delivered (P Cox = .057) were the most important prognostic factors. Prophylactic intrathecal MTX therapy and splenectomy did not influence survival. Although MH is an aggressive disease with a poor prognosis, it is potentially curable. Systematic and aggressive treatment should further improve the outcome.     

Characterization of a factor IX variant with a glycine207 to glutamic acid mutation

Factor IXTaipei9 is a factor IX variant from a hemophilia B patient with reduced levels of circulating protein molecules (cross-reacting material reduced, CRM). This variant contained a glycine (Gly) to glutamic acid (Glu) substitution at the 207th codon of mature factor IX. The functional consequences of the Gly-->Glu mutation in factor IXTaipei9 (IXG207E) were characterized in this study. Plasma-derived IXG207E exhibited a mobility similar to that of normal factor IX on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Its specific activity was estimated to be 3.5% that of the purified normal factor IX in a one-stage partial thromboplastin time assay (aPTT). Cleavage of factor IXG207E by factor XIa or factor VIIa-tissue factor complex appeared to be normal. When the calcium-dependent conformational change was examined by monitoring quenching of intrinsic fluorescence, both normal factor IX and IXG207E exhibited equivalent intrinsic fluorescence quenching. Activated factor IXG207E (IXaG207E) also binds antithrombin III equally as well as normal factor IXa. However, aberrant binding of the active site probe p-aminobenzamidine was observed for factor XIa-activated factor IXG207E, indicating that the active site pocket of the heavy chain of factor IXaG207E was abnormal. Moreover, the rate of activation of factor X by factor IXaG207E, as measured in a purified system using chromogenic substrates, was estimated to be 1/40 of that of normal factor IXa. A computer-modeled heavy-chain structure of factor IXa predicts a hydrophobic environment surrounding Gly-207 and this Gly forms a hydrogen bound to the active site serine-365. The molecular mechanism of the Gly-->Glu mutation in factor IXTaipei9 might result in the alteration of the microenvironment of the active site pocket which renders the active site serine-365 inaccessible to its substrate.     

Adenosine preconditioning attenuates hepatic reperfusion injury in the rat by preventing the down-regulation of endothelial nitric oxide synthase

Background

Previous work has suggested that in the liver, adenosine preconditioning is mediated by nitric oxide. Whether the endothelial isoform of nitric oxide synthase plays a part in this mechanism has however not yet been investigated.

Methods

Wistar rats were used (6 in each group) – Groups: (1) sham, (2) ischemia-reperfusion, (3) adenosine + ischemia-reperfusion, (4) endothelial isoform inhibitor + adenosine + ischemia-reperfusion.

Results

Using immunohistochemistry, this study has revealed a decrease in the expression of endothelial nitric oxide synthase following hepatic ischemia-reperfusion. This was prevented by adenosine pre-treatment. When an inhibitor of endothelial nitric oxide synthase was administered prior to adenosine pre-treatment, pre-conditioning did not occur despite normal expression of endothelial nitric oxide synthase.

Conclusions

These findings suggest that adenosine attenuates hepatic injury by preventing the downregulation of endothelial nitric oxide synthase that occurs during ischemia-reperfusion.