Management of factor XI deficiency in oncological liver and colorectal surgery by therapeutic plasma exchange: A case report.

INTRODUCTION: Factor XI (FXI) deficiency is a rare congenital hemostatic disorder associated with increased bleeding tendency in trauma, surgery or when other hemostatic defects are present. Perioperative hemostatic management of a patient with a severe FXI deficiency undergoing major oncological liver and colorectal surgery with therapeutic plasma exchange (TPE) with fresh frozen plasma (FFP) is reported. CASE DESCRIPTION: A 54-year-old male with severe FXI deficiency was scheduled for resection of synchronous rectal cancer and multiple liver metastases. Baseline prothrombin time (PT) was 97 %, activated partial thromboplastin time (aPTT) 89 s(s) and FXI levels <1 IU/dL. The rotational thromboelastometry (ROTEM™) presented a prolonged INTEM clotting time (CT) = 443 s (RV 100-240 s) and a clot formation time (CFT) = 110 s (RV 30-100 s). TPE with FFP was carried out achieving FXI levels up to 46 IU/dL and an aPTT of 33 s, normalizing thromboelastometry parameters to an INTEM CT = 152 s and a CFT = 86 s before the procedure. After surgery, the patient received daily FFP to maintain FXI levels above 30 IU/dL until discharge on the eighth day. A total of 30 FFP units were transfused during hospital stay. No significant bleeding events neither transfusion related complications were observed during the perioperative period. CONCLUSION: Given the lack of correlation between FXI levels and bleeding risk, a multidisciplinary approach based on daily FXI levels monitoring, close clinical assessment and factor supplementation is mandatory. In conclusion, TPE with FFP is an efficacious alternative strategy to correct severe FXI deficiency in patients undergoing major surgery.

Trans-sialidase inhibition assay for the detection of Trypanosoma cruzi infection in blood donor samples from Argentina.

BACKGROUND AND OBJECTIVES: Conventional serology tests for Trypanosoma cruzi blood banks screening are neither sensitive nor specific enough, and currently no gold standard assay is available. Trans-sialidase inhibition assay (TIA) detects neutralizing antibodies against T. cruzi trans-sialidase. Conventional serology inconclusive, positive and negative blood donor samples were evaluated by employing TIA as a supplementary test. MATERIALS AND METHODS: Three hundred and twenty-one blood donor samples were tested using a combination of assays. Based on the results of testing, these were divided into a number of groups. All samples were tested by TIA. RESULTS: In conventional serology inconclusive samples 48.1% were TIA-positive, 1/54 conventional serology positive samples was TIA-negative. All negative samples from donors without epidemiological risks were TIA-negative; 1/48 was positive in those with epidemiological risk. CONCLUSION: Trans-sialidase inhibition assay application in blood banks may be useful to resolve inconclusive samples, and thus improves donor counseling and allows individual re-entry. The use of TIA in samples from negative conventional test donors but positive epidemiological antecedents may contribute to decrease transfusional risk.

Antibodies to Trypanosoma cruzi among blood donors in Buenos Aires, Argentina.

OBJECTIVES: The aim of this work was to study the prevalence of anti-Trypanosoma cruzi in the blood donor population in Buenos Aires, to compare the relative sensitivity and specificity of the two screening tests used and to confirm the results with a third assay. MATERIAL AND METHODS: Between May 1995 and July 1999, 64,887 blood donor consecutive samples were screened with the following commercial tests: indirect hemagglutination (IHA) (Polychaco, Buenos Aires, Argentina) and enzyme-linked immunosorbent assay (ELISA) (40,222 with Chagatek, Organon Teknika, Buenos Aires, Argentina, and 24,665 with Chagas EIA, Abbott, São Paulo, Brazil). Repeatedly reactive samples in one or both tests were analyzed with a third method: dot blot (Bio Chagas, Gador, Buenos Aires, Argentina) or particle agglutination (Serodia, Fujirebio, Tokyo, Japan). Sera that reacted in at least two tests were considered positive. RESULTS: The seroprevalence was 2.66% (1744 samples were reactive for one or both screening tests), and 1.46% (949 samples) were confirmed positive. The ELISAs proved to be more sensitive (relative sensitivity: 99.67-99.71%) whereas 192 samples (0.47%) were IHA false-negatives (relative sensitivity: 79.77%). Relative specificity for EIA was 98.47--99.23% and for IHA 99.85%. CONCLUSIONS: Results suggest the need of performing two screening tests for Chagas disease in blood banks from endemic areas and the importance of a third confirmatory assay to avoid unnecessary medical counseling.

[Is TT virus (TTV) a true hepatitis virus cause?]. / Virus TT (TTV). Es un verdadero causante de hepatitis?

TT virus (TTV) was first detected in the blood of three patients with elevated serum alanine aminotransferase following transfusion who were negative for all known hepatitis viruses. This virus exhibited hepatotropism, and its titers correlated with elevation in serum aminotransferase concentration suggesting that it was a true hepatitis virus. Moreover, it was demonstrated that the presence of TTV DNA is not associated with biochemical or histologic evidence of liver injury. The virus has been found worldwide with a high prevalence in the general population and there is evidence that it may be transmitted by parenteral exposure to blood, enterally and transmitted from mother to child. An association between TTV infection and acute or chronic hepatitis or other diseases has not been consistently observed.

[Prevalence of Trypanosoma cruzi antibodies in blood donors]. / Prevalencia de anticuerpos anti-Trypanosoma cruzi en donantes de sangre.

Blood transfusion is the second most common transmission route of Chagas' disease in endemic areas. Discrepancies between the available diagnostic kits are common, which indicates that a single test is not satisfactory. The aim of this work was to study the seroprevalence of anti-Trypanosoma cruzi markers, to compare sensitivity and specificity of the two screening assays currently in use and to confirm the results with a third test. A total of 20,860 volunteer blood donors were studied. Donations were screened with indirect hemagglutination assay (IHA) and enzyme immunoassay (EIA). Repeatedly reactive samples were assayed with an EIA carried out on strips, to which a mixture of T. cruzi antigens was applied as an horizontal line (DB). Sera that reacted in at least two tests were considered positive. A total of 576 samples were reactive for one or both screening tests (2.76%) and 391 of them (1.87%) were confirmed positive. EIA proved to be more sensitive, with no false negative results (100% sensibility), whereas 98 samples (0.47%) were IHA false negative (74.93% sensibility). Specificity for EIA was 99.3% and for IHA 99.8%. In our case, almost 0.9% of donated blood is discarded because of false reactive anti-T. cruzi results; two thirds correspond to false positive EIA and one third to false positive IHA. It is important to note that in our population we have not registered false negative results for EIA but there were false negative IHA. This fact implies that although the first method is less specific, it is much more sensitive. It is important to confirm the screening results in order to avoid unnecessary donor counselling and permit future donations. The DB test employed in our study results a useful alternative for this purpose.

[Heteroimmune hemolytic anemia associated with antilymphocyte globulin treatment in a patient with aplastic anemia]. / Anemia hemolítica heteroinmune asociada a tratamiento con globulina antilinfocítica en un paciente con anemia aplástica.

A 24-year-old male patient with a severe aplastic anemia (SAA) was treated with equine-antilymphocyte globulin (ALG). As complication of this treatment he developed a severe heteroimmune hemolytic anemia mediated by anti-species pan-agglutinin antibodies present in ALG. In spite of the fact that ALG is absorbed with red-cell stroma and platelets to remove anti-erythrocyte and anti-platelet contaminating antibodies, often only partial absorption is achieved, and the remaining antibodies are passively acquired by the recipient. Neutropenia and especially thrombocytopenia are usual complications of this treatment, but it is also possible to detect anti-erythrocyte antibodies in the serum and on the red cells of those patients. However, the unusual severity of the hemolysis suffered by our patient, with a striking decrease of the hemoglobin levels (Fig. 1) can be ascribed to the administration of ALG at a time at which the hematocrit was close to normal as a result of the previous administration of anabolics. It is likely that in severely anemic patients, with a high transfusional demand, such a hemolytic episode may remain undetected. The patient acquired reactivity to the direct antiglobulin test, as well as the positive results of investigation of unexpected antibodies and compatibility testing can be accounted for by the fact that commercial antihuman globulin serum (AGS) contains antibodies reacting with a globulin component shared by human and horse sera. Neutralization of AGS with ALG administered to the patient removed those cross-reacting antibodies, making it possible to perform reliable transfusion compatibility testing and to rule out the eventual presence of hidden alloantibodies or warm autoantibodies. Neutralized Coombs serum maintained its human antiglobulin properties unaltered (Table 1).(ABSTRACT TRUNCATED AT 250 WORDS)

[Determination of anti-HTLV-I/II antibodies: Experience in 28,897 blood donations in Buenos Aires]. / Determinación de anticuerpos anti HTLV-I/II: experiencia en 28,897 donantes de sangre en Buenos Aires.

PURPOSE: The first human retrovirus, HTLV-I, was isolated in 1980; HTLV-II was described later. The former is endemic in southwestern Japan, the Caribbean and equatorial Africa; whereas the latter prevails in intravenous drug addicts, being also endemic in American indian populations. Both viruses are either sexually transmitted, from mother to child mainly by breast-feeding, by blood transfusion or by sharing contaminated needles. With regard to transmission, since they are intracellular viruses, it occurs only when whole blood or cellular components are transfused; this is not the case when either plasma or plasma derivatives are used. The likelihood of transmission decreases as the storage time increases. HTLV-I is associated, at least, with two diseases: adult T-cell leukaemia/lymphoma (ATLL), and the tropical spastic paraparesis (TSP) or HTLV-I-associated myelopathy (HAM). ATLL occurs after a latency period of 20 to 30 years; whereas the incubation period ranges from 3 to 5 years in the case of the neurological disease. Most individuals infected with the virus remain healthy; the risk of developing the hematological complication is 2-4% whereas it is below 1% in the case of TSP. No clear association of HTLV-II with any known disease has been reported as yet. In this study, we have assessed the prevalence of HTLV-I and HTLV-II in the sera of the blood donors who have come to our Division, with the aim of avoiding the spreading of this oncogenic virus by transfusion. This study could serve as a measure of the infection in the general population. MATERIAL AND METHODS: A total of 28,897 samples were analyzed from May 1993 to January 1995. Anti-HTLV-I/II antibodies were analyzed by the method of passive agglutination of gelatin participles (PA). Samples which reacted were tested again by the same method, and those reacting for the second time were further confirmed by Western blot (WBT), a method with the ability to differentiate between antibodies anti-HTLV-I and anti-HTLV-II. RESULTS: Of the 28,897 samples, 47 were repeatedly reactive by PA (0.16%). Analysis by WBT resulted in 10 reactive results with HTLV-I (0.035%), 2 reactive results with HTLV-II (0.007%); in one sample it could not be determined whether the anti-HTLV-I or anti-HTLV-II antibody was present. Of the remaining samples, 21 were non-reacting, whereas 13 were indeterminated. CONCLUSION: Prevalence of HTLV-I and HTLV-II seropositive blood donors is low and similar to that found in other non-endemic countries. We believe that routine evaluation of anti-HTLV-I and HTLV-II antibodies in blood donors would be warranted in our country, since transmission of the viruses by transfusion of blood components has been clearly shown. It is possible that the recipients of the reactive units do not develop the disease. Nevertheless, these individuals constitute an important source of virus dissemination, both during the perinatal period and by sexual intercourse. In fact, advise to seropositive donors would prevent transmission by these routes. Lastly, it should be noticed that investigation of anti-HTLV-I/II antibodies could result in a surrogate method for detecting other viral infections transmitted by these routes.

Management of a severe transfusional problem in a patient with alloantibody to Kpb (K4).

The case of a 58-year-old male with severe anemia after hemicolectomy is described. The patient proved to be Kp(b-), and the serum contained anti-Kpb. Because no Kp(b-) donors were available, two incompatible units are administered after intravenous gammaglobulin (400 mg/kg/day) and hydrocortisone (500 mg). The tolerance was good, without signs of increased red cell destruction. Pending the arrival of compatible blood from the American Red Cross, the hematocrit reached 18%, and the direct antiglobulin test remained negative.

HBV-HDV en donantes de sangre: prevalencia y análisis molecular / Hepatitis B virus and Hepatitis D virus in blood donors: prevalence and molecular analysis in an Argentinean population

The aim of this report was to determine retrospectively the prevalence of hepatitis viruses infection by both HBV and HDV, and to identify the genotype in a population of blood donors. From 42,055 sample of donors, the authors study the hepatitis B virus and hepatitis D virus prevalence and molecular analysis in an Argentinean population. The results obtained are detailed in the article.

Anemia hemolitica heteroinmune asociada a tratamiento con globulina antilinfocitica en un paciente con anemia aplastica / Heteroimmune hemolytic anemia associated with antilymphocyte globulin treatment in a patient with aplastic anemia

Se describe el caso de un paciente de 24 años de edad con anemia aplástica (AAS) tratada con globulina antilinfocítica (GAL) de origen equino, que desarrolla como complicación un grave cuadro de anemia hemolítica heteroinmune mediada por anticuerpos panaglutinantes anti-especie presentes en al GAL. La reactividad adqurida por el paciente en la prueba de Coombs directa, así como en la investigación de anticuerpos irregulares y en los tests de compatibilidad transfusional se explica por la existencia en el suero antiglobulina humana (SAGH) comercial de anticuerpos que reaccionan con un componente globulínico compartido por los sueros humanos y equino. La neutralización del SAGH con la propia GAL administrada al paciente removió esos anticuerpos de reacción cruzado, resultando de gran utilidad para poder llevar a cabo confiablemente la sprueba de compatibilidad transfusional y de detección de anticuerpos séricos