Blood Bank Donors Research Articles

Epstein-barr virus (EBV) in healthy carriers: Distribution of genotypes and 30 bp deletion in latent membrane protein-1 (LMP-1) oncogene.

There are two types of Epstein Barr virus (EBV): EBV-1 and EBV-2, distinguished by genomic polymorphism in the genes encoding the nuclear antigens (EBNA-2, -3A, -3B, -3C). Latent membrane protein 1 (LMP-1) is an EBV protein with known oncogenic properties. Different variants had been described; among them, a 30 base pair (bp) deletion (del-LMP-1) had been reported in benign and malignant pathologies, but there is little information about its frequency in healthy populations. The aim of this study was to determine the distribution of the EBV genotypes and the 30 bp deletion frequency, in EBV healthy carriers from Argentina. Analysis of EBNA-3C and LMP-1 genes were done by polymerase chain reaction (PCR) followed by Southern blot hybridization on DNA of peripheral blood mononuclear cells (PBMCs) from blood bank donors. EBV-1 was present in 75.9% of samples, EBV-2 in 14.6%, and co-infections with both types in 6.5%. The deleted LMP-1 variant was found in 7.4% of analyzed samples, corresponding 3.2% to deleted variant alone and 4.2% to co-infections with non-deleted form. The non-deleted variant was found in 64.6% whereas in the remaining 28%, no PCR product was detected. These results showed that EBV-1 was the more prevalent type in healthy carriers of Argentina, similar to reports from others countries. A predominance of the non-deleted LMP-1 variant was observed. The presence of co-infections with both types and variants demonstrated that healthy individuals may also harbor multiple EBV infections.

Association between 10 Microsatellite Markers and Nonsyndromic Cleft Lip Palate in the Chilean Population

The objective of this case-control study was to evaluate the possible association between nonsyndromic cleft lip/palate (NSCLP) and 10 genetic markers in four chromosomal regions in the admixed Spanish-Amerindian Chilean population. Study participants included 56 patients with NSCLP identified and interviewed for positive family history during the course of clinical examinations at different rehabilitation centers in the cities of Santiago and Talca, Chile. A control group of 59 normal individuals without known familial antecedents of clefting was obtained from blood bank donors of the University Hospital, University of Chile. Cases and controls belonged to low- to low-middle socioeconomic strata. Ten markers from chromosome 4p, 4q, 6p, 17q, and 19q were assessed (MSX1, D4S175, D4S192, F13A1, EDN1, D6S89, D6S105, D6S109, D17S579, BCL3). Four of them showed significant deviations from Hardy-Weinberg expectations in controls, according to the exact test (D4S192, BCL3, F13A1, and D6S89). The case-control comparison by means of the CLUMP program showed significant differences only in BCL3, and D6S109 almost reached statistical significance. Most of the genetic regions with positive results in Caucasian populations may not be involved in NSCLP in Chile, regardless of the positive evidence for the candidate region on chromosome 19. Similar findings have been reported recently in the Chinese population.

Von Willebrand factor-cleaving protease (ADAMTS13) activity in normal non-pregnant women, pregnant and post-delivery women

ADAMTS13 dysfunction has been involved in the pathogenesis of Thrombotic Thrombocytopenic Purpura. This disorder occurs more frequently in women and, in 13% of them, is associated with pregnancy. However, there is little information on the protease behaviour in normal pregnancy. We studied von Willebrand factor and ADAMTS13 activity changes in normal non-pregnant, pregnant and post-delivery women. Fifty-five non-pregnant women, normal blood bank donors, who were not taking contraceptive pills were included as controls. A prospective cross-sectional study of 270 normal pregnant and post-delivery women was carried out. ADAMTS13 activity decreased progressively as from the period of 12-16 weeks up to the end of early puerperium (mean 52%, range 22-89, p < 0.0001), to increase slightly thereafter. Nulliparous presented mildly lower levels of ADAMTS13 activity than parous women (65% vs. 83 %, p = 0.0003), and primigravidae than multigravidae between 6-11 weeks up to 17-23 weeks of pregnancy (69% vs. 80%, p = 0.005). Although in all women the protease levels were the same by blood groups, the O blood group non-pregnant women showed a higher mean of ADAMTS13 activity than those non-O (78% vs. 69%, p = 0.064). Our results suggest that the changing levels of protease activity during pregnancy and puerperium, induced by unidentified mechanisms, could render the peripartum time more vulnerable to developed thrombotic microangiopathies.

Evaluation of BRCA2 in the genetic susceptibility of familial esophageal cancer

Previous studies of esophageal squamous cell carcinoma (ESCC) have shown a high frequency of allelic loss on chromosome 13q, infrequent somatic mutations in BRCA2, and a suggested association between a positive family history (FH+) of upper gastrointestinal cancer and germline BRCA2 mutations. In all, 70 ESCC patients (44 FH+ and 26 FH-) were examined by direct full sequencing of germline DNA for BRCA2 mutations. In addition, 28 family members of three of these patients and 232 unrelated healthy blood bank donor controls were examined for the mutations identified in the 70 ESCC patients. Five BRCA2 germline mutations, including three not previously reported (N1600del, A2054P, and V2109I), were identified in six of 44 FH+ patients, but none of 26 FH- patients (14 vs 0%, P=0.078), consistent with our previous findings (3/34 or 9% FH+ vs 0/22 or 0% FH-, P=0.27). The cumulative frequency of BRCA2 germline mutations in ESCC patients in this and our previous study combined is 12%, with all mutations found in FH+ as opposed to FH- cases (9/78 or 12% FH+ vs 0/48 or 0% FH-, P=0.013). We conclude that germline mutations in BRCA2 in ESCC patients from this high-risk area of China are more frequent in FH+ than FH- cases, suggesting that BRCA2 may play a role in genetic susceptibility to familial ESCC.

Overexpression of the dual-specificity MAPK phosphatase PYST2 in acute leukemia.

In a previous study we used gene expression arrays to identify genes that are more highly expressed by leukemic than by non-leukemic leukocytes from acute myelogenous leukemia patients. One of such genes was Phosphorylates tyrosine serine threonine 2 (PYST2), a dual-specificity Mitogen-activated protein (MAP) kinase (MAPK) phosphatase. In the present study, high levels of PYST2 mRNA were detected by RT-PCR and by Northern blotting in bone marrow (BM) leukocytes and in peripheral blood mononuclear cells from additional eight AML patients. No PYST2 mRNA was detected in nine out of twelve samples of Peripheral blood mononuclear cells (PBMC) from healthy blood bank donors and very low levels were detected by the same techniques in the other three PBMC samples from the healthy donors. Relatively high levels of PYST2 were detected in a variety of myeloid leukemia and other cancer cell lines. In view of the potential role played by PYST2 in MAPK signaling cascades we propose that an over expression of PYST2 in malignant cells may reflect a disrupted or an altered MAPK signaling pathway in malignancy processes.

Prevalence of human T-lymphotropic virus type 1 among blood donors from Mashhad, Iran.

The city of Mashhad is the capital of Khorasan, the northeastern province of Iran, which has been recognized as an area where human T-lymphotropic virus type 1 (HTLV-1) infection is endemic. All serum samples from blood donors are routinely screened for HTLV-1 by using enzyme-linked immunosorbent assay (ELISA). In the present study, 28,926 donors (81.86% male and 18.14% female) with a mean age of 32 years (range, 18 to 65 years) were screened in a 6 months period (July to December 1999). Of these donors in the primary screening, 228 (0.78%) tested positive by ELISA. The positive samples were confirmed by Western blot (WB) analysis. The WB results indicated that, of 228 positive ELISA specimens, 91.2% (208 specimens) were HTLV-1, 4.82% (11 specimens) were HTLV, 3.5% (8 specimens) were indeterminate, and 0.44% (1 specimen) was not confirmed. HTLV refers to samples in which the complete viral antigen banding patterns on WB strips were not present. In order to further evaluate the detection methodologies used, the HTLV-1-seropositive samples, the indeterminant samples, and/or HTLV samples were examined and confirmed by PCR. The HTLV samples were determined to be HTLV-1, the remaining samples were indeterminant, and the negative sample could not be confirmed for HTLV-1 by PCR. The prevalence of HTLV-1 infection in our study was 0.77% among blood bank donors, which reconfirms the city of Mashhad as an area where the virus is endemic compared to other regions in the world. The incidence was correlated with increasing age, and it was higher in females than in males.

Blood transfusion related paediatric HIV/AIDS in Ile-Ife, Nigeria

This prospective study was aimed at determining the contribution of blood transfusion to paediatric HIV infection in Ile-Ife, Nigeria. It involved HIV screening of consecutive children presenting at the Obafemi Awolowo University Teaching Hospital (OAUTH), Ile-Ife, between March 1996 and March 2001, with any of the signs in the WHO clinical case definition for paediatric AIDS. The HIV serostatus of blood donors at the OAUTH was also extracted from the blood bank records. Of the 263 children who met the criteria for HIV screening, 35 (13.3%) were HIV-positive. Eighteen of the 263 children screened had a history of blood transfusion and 12 (66.7%) of the 18 were HIV-positive. Eleven (91.7%) of the 12 HIV-positive patients were transfused in private hospitals with blood collected from private laboratories. The blood with which the HIV-positive children were transfused was unscreened in three, screened in two and the HIV status unknown in the others. The sole voluntary donor was an HIV-positive father whose child received his unscreened blood. Only two (16.7%) of the mothers of the previously transfused HIV-positive children were also HIV-positive. 'Paid' donors accounted for 94.3% of total donors in OAUTH blood bank records and cumulative HIV-positivity was statistically significantly higher in 'paid' donors than in voluntary donors (p=0.005). We conclude that transfusion with unsafe blood is an important route for HIV infection in symptomatic children and that HIV-positivity is higher among paid donors. We recommend the establishment of a national blood transfusion service, which is presently non-existent in Nigeria, and the enforcement of laws guiding blood transfusion. Voluntary blood donation should be encouraged and health workers in the private sectors educated on the link between blood transfusion and HIV infection.

Lack of association between hyperprolactinemia and soluble IL-2 receptor levels in systemic lupus erythematosus.

The aim of the study was to evaluate the association between hyperprolactinemia and T lymphocyte activation through the soluble IL-2 receptor (sIL-2R) in systemic lupus erythematosus (SLE) patients. Seventy SLE patients, 18 of them with hyperprolactinemia (HPRL), were compared with 18 normoprolactinemic (NPRL) patients and 10 age-matched healthy blood-bank donor women. Patients were evaluated by means of the SLE activity index (SLEDAI). Total serum IgG and sIL-2R levels were determined by an ELISA assay. Differences between sIL-2R and IgG serum levels in patients and controls were examined by Kruskal-Wallis analysis and a Spearman r correlation to determine the association between sIL-2R, IgG and prolactin (PRL) levels. IgG and sIL-2R serum levels did not differ significantly between HPRL and NPRL patients: 1827.3 (1428-2226) vs 2028.8 (1586-2467) mg/dl and 882.2 (511-1254) vs 740.1 (534-946.4) U/ml, respectively (confidence interval 95%). In the total SLE group, sIL-2R and IgG serum levels were positively associated (P = 0.0009), however, this was not the case for sIL-2R and PRL (P > 0.49). We did not demonstrate an association between HPRL and lymphocyte activation measured through serum sIL-2R in female patients with SLE.

Immunologic Profile of Highly Exposed Yet HIV Type 1-Seronegative Men

The host immune factors that determine susceptibility to HIV-1 infection are poorly understood. We compared multiple immunologic parameters in three groups of HIV-1-seronegative men: 14 highly exposed (HR10), 7 previously reported possibly to have sustained transient infection (PTI), and a control group of 14 low risk blood bank donors (BB). Virus-specific cellular immune assays were performed for CD4(+) T helper cell responses, CD8(+) cytotoxic T lymphocyte activity, CD8(+) cell chemokine release, and CD8(+) cell-derived antiviral soluble factor activity. General immune parameters evaluated included CCR5 genotype and phenotype, interferon alpha production by PBMCs, leukocyte subset analysis, and detailed T lymphocyte phenotyping. Comparisons revealed no detectable group-specific differences in measures of virus-specific immunity. However, the HR10 group differed from the BB group in several general immune parameters, having higher absolute monocyte counts, higher absolute CD8(+) T cell counts and percentages, lower naive and higher terminal effector CD8(+) cells, and lower levels of CD28(+)CD8(+) cells. These changes were not associated with seropositivity for other chronic viral infections. The PTI men appeared to have normal levels of monocytes and slightly elevated levels of CD8(+) T cells (also with increased effector and decreased naive cells). Although we cannot entirely exclude the contribution of other chronic viral infections, these findings suggest that long-lived systemic cellular antiviral immunity as detected by our assays is not a common mechanism for resistance to infection, and that resistance may be multifactorial. General immune parameters reflected by CD8(+) T cell levels and activation, and monocyte concentrations may affect the risk of infection with HIV-1, and/or serve as markers of exposure.

Oral colonization by Candida spp. among AIDS household contacts

This study was designed to investigate the oral yeast colonization rate of household contacts of AIDS patients. Sixty-four AIDS household contacts were sequentially enrolled along with 103 HIV-negative blood bank donors (control group). Samples were obtained by swabbing the oral mucosa. Yeast isolates were identified by classical methods and antifungal susceptibility testing was performed according to NCCLS microbroth assay. Candida spp. was recovered from the oral cavity of 33% of the AIDS household contacts, in contrast with 14% of the control group (P = 0.003 or P = 0.04 after adjusting for oral prosthesis use). Candida albicans was the most frequently isolated species in both groups. All of the isolates were susceptible to fluconazole, itraconazole and ketoconazole. In conclusion, we were able to demonstrate a higher colonization rate in the AIDS household contacts group compared with the control group. No resistant isolates to antifungal drugs was observed. We suggest that the contact with AIDS patients may play a role as a risk factor for developing oral colonization by Candida spp.

Confirmation of invasive meningococcal disease by single point estimation of IgM antibody to outer membrane protein of Neisseria meningitidis

The sensitivity of laboratory confirmation of invasive meningococcal disease (IMD) by culture or PCR is affected by prior antibiotic treatment and decreasing use of early lumbar puncture. Serological diagnosis of IMD is not widely used because of reliance on paired serum samples. The application of single point estimations of IgM antibodies in the diagnosis of IMD was explored. Outer membrane proteins from a mix of commonly encountered meningococcal serotypes were partially purified and used as an antigen in an enzyme immunoassay for the detection of IgM antibody. The cut-off for the assay was derived using sera from blood bank donors and the accuracy then evaluated with sera from patients with culture-confirmed IMD, other bacterial infections and culture-proven nasopharyngeal colonisation with Neisseria meningitidis. The coefficient of variability of the assay was < 10% in negative, mid- and high-range positive sera and the specificity of the assay was at least 93%. In sera collected from 49 adult patients at various times after positive blood or CSF culture-confirmed IMD, the assay had a sensitivity of 100% in specimens collected between 5 and 18 days. At the time of isolation of meningococci from either blood or CSF, eight of 29 sera were IgM-positive, but beyond 70 days no positive results were detected. No differences were seen in the IgM responses in patients from whom different serogroups of N. meningitidis were recovered. Serological examination by single point IgM enzyme immunoassay (EIA) offers the possibility of an expanded laboratory confirmation of IMD in adults for samples taken between 5 and 18 days after onset.

A postgenomic approach to identification of Mycobacterium leprae-specific peptides as T-cell reagents.

To identify Mycobacterium leprae-specific human T-cell epitopes, which could be used to distinguish exposure to M. leprae from exposure to Mycobacterium tuberculosis or to environmental mycobacteria or from immune responses following Mycobacterium bovis BCG vaccination, 15-mer synthetic peptides were synthesized based on data from the M. leprae genome, each peptide containing three or more predicted HLA-DR binding motifs. Eighty-one peptides from 33 genes were tested for their ability to induce T-cell responses, using peripheral blood mononuclear cells (PBMC) from tuberculoid leprosy patients (n = 59) and healthy leprosy contacts (n = 53) from Brazil, Ethiopia, Nepal, and Pakistan and 20 United Kingdom blood bank donors. Gamma interferon (IFN-gamma) secretion proved more sensitive for detection of PBMC responses to peptides than did lymphocyte proliferation. Many of the peptides giving the strongest responses in leprosy donors compared to subjects from the United Kingdom, where leprosy is not endemic, have identical, or almost identical, sequences in M. leprae and M. tuberculosis and would not be suitable as diagnostic tools. Most of the peptides recognized by United Kingdom donors showed promiscuous recognition by subjects expressing differing HLA-DR types. The majority of the novel T-cell epitopes identified came from proteins not previously recognized as immune targets, many of which are cytosolic enzymes. Fifteen of the tested peptides had > or =5 of 15 amino acid mismatches between the equivalent M. leprae and M. tuberculosis sequences; of these, eight gave specificities of > or =90% (percentage of United Kingdom donors who were nonresponders for IFN-gamma secretion), with sensitivities (percentage of responders) ranging from 19 to 47% for tuberculoid leprosy patients and 21 to 64% for healthy leprosy contacts. A pool of such peptides, formulated as a skin test reagent, could be used to monitor exposure to leprosy or as an aid to early diagnosis.

Verification of the drug history given by potential blood donors: results of drug screening that combines hair and urine analysis.

Besides modern virus-screening methods, the avoidance of transfusion transmission of viral diseases is based on the best possible selection of healthy donors. Unfortunately, most of the relevant behavior-related risk factors are not accessible to objective verification. Drug screening can be used to validate a defined section of donor statements. It may be assumed that donors who conceal drug consumption may also conceal other relevant risk factors. Hair and urine samples from 186 young potential donors who denied having consumed drugs were investigated by gas chromatography with mass selective detection and a urine fluorescence polarization immunoassay for cannabinoids, amphetamine and amphetamine derivatives, cocaine, and opiates. Ten potential donors with 14 positive results on hair and urine analyses (6x cannabinoids, 4x cocaine, 1x opiates, 3x dihydrocodeine) could be identified in the population investigated. The donor history is not adequate for identifying potential donors with risk factors. Deliberately false statements concerning risk factors are a clear breach of trust between the blood bank and potential donors. These unreliable donors represent an incalculable risk for the transfusion recipient. Therefore, it is appropriate to validate donor statements about drug consumption by random hair and urine analyses and to exclude from the donor pool all persons revealed as drug users.

Differences in clinical sensitivity of ELISA tests for autoantibodies with human and bovine extractable nuclear antigens.

Bovine antigens are routinely used in indirect ELISA tests to detect autoantibodies against extractable nuclear antigens (ENA). Here we investigate the difference in clinical sensitivity between ELISA tests prepared with native human and bovine antigens. SSA and SSB were obtained from spleen and nRNP/Sm complex from thymus. Each antigen was extracted with the same immunoaffinity column. ELISA tests with human and bovine antigens were set up under the same conditions of clinical specificity established on 50 blood bank donors. Of 109 random SLE and Sjogren's syndrome sera 49% and 35% were positive, respectively, for human and bovine SSA, 26% and 16% for SSB. Of 98 random SLE sera 52% and 41% were positive for human and bovine nRNP/Sm, respectively. A few specimens reacted only with bovine antigens, probably false positive reactions. The relative clinical sensitivity for all specimens identified as positive by human and/or bovine antigens was significantly higher with human than with bovine SSA, (93% vs 67%; P<0.001, chi2), SSB (93% vs 50%; P<0.001), and for nRNP/Sm (96% vs 75%; P<0.01). However, for values that exceeded 2.5-4 times the upper normal limit, the levels were similar for human and bovine antigens. We concluded that native human antigens offer clinical sensitivity superior to native bovine antigens for the measurement of anti-ENA antibodies by ELISA.

A longitudinal study of in vitro IFNγ production and cytotoxic T cell responses of tuberculosis patients in The Gambia

Setting: This study was carried out at the MRC Laboratories, The Gambia.Objectives: To characterize the antigen-specific IFNγ production and cytotoxic T cell (CTL) responses of patients during active tuberculosis, treatment, and following recovery.Design: PBMC were isolated from 37 patients with tuberculosis and incubated with either PPD, live M. bovis BCG, or no antigen and IFNγ production measured after 7 days. CTL activity against these antigens was determined using autologous antigen-pulsed monocyte-derived macrophages as target cells. A subset of these patients (7–18 depending on antigen and assey used) were tested 2 months into drug treatment and 3 months after discharge. A group of blood bank donors (n= 21) were also tested to evaluate IFNγ responses in endemic controls; a subset (n= 16) were also tested for CTL activity.Results: The ability to produce IFNγ in response to mycobacterial antigens correlated with the Mantoux skin test status of the patient. IFNγ production to live M. bovis BCG was diminished at diagnosis but returned after 2 months of drug treatment, and was sustained after completion of drug therapy. The CTL responses to both PPD and live M. bovis BCG were reduced during the period of drug treatment compared to those at diagnosis, but returned to the original levels after recovery.Conclusions: Drug treatment induced marked alterations in the immune responses of tuberculosis patients with induction of IFNγ production in response to stimulation with live M. bovis BCG. This may indicate activation of both CD4 and CD8 T cells.

External quality assessment of flow cytometric HLA-B27 typing

A biannual external quality assurance (EQA) scheme for flow cytometric typing of the HLA-B27 antigen is operational in The Netherlands and Belgium since 1995. We report here on the results of the first seven send-outs to which 36 to 47 laboratories participated. With the send-out, four specimens from blood bank donors, who had been typed for HLA Class I antigens by complement-dependent cytotoxicity, were distributed. Subtyping of the HLA-B27 allele was performed by PCR-SSP. Ten samples were HLA-B27(pos) (all HLA-B*2705) and 18 were HLA-B27(neg). For flow cytometry, the most widely monoclonal antibody (MoAb) used was FD705, followed by GS145.2 and ABC-m3. The majority of laboratories used more than 1 anti-HLA-B27 MoAb for typing. The HLA-B27(pos) samples were correctly classified as positive by the large majority of participants (median 95%; range 85% to 100% per send out); some participants considered further typing necessary and misclassification as negative was only sporadically seen. The classification of HLA-B27(neg) samples as negative was less straightforward. Ten samples were correctly classified as such by 97% (82% to 100%) of the participants, whereas 64% (range 53% to 70%) of the participants classified the remaining eight samples as HLA-B27(neg). There was no significant prevalence of a particular HLA-B allele among these eight "poor concordancy" samples as compared to the ten "good concordancy" samples. Inspection of the reactivity patterns of the individual MoAb with HLA-B27(neg) samples revealed that ABC-m3 showed very little cross-reactivity apart from its well-known cross-reactivity with HLA-B7, whereas the cross-reactivity patterns of GS145.2 and FD705 were more extensive. The small sample size (n = 18) and the distribution of HLA-B alleles other than HLA-B27 did not allow assignment of specificities to these cross-reactions. Finally, we showed that standardized interpretation of the combined results of two anti-HLA-B27 MoAb reduced the frequency of false-positive conclusions on HLA-B27(neg) samples. In this series, the lowest frequency of false-positive assignments was observed with the combination of the FD705 and ABC-m3 MoAb.

TSP/HTLV-1 ASSOCIATED WITH BLOOD TRANSFUSION IN JUJUY. ARGENTINA.

P095 Introduction: The HTLV-1 seroprevalence among blood bank donors in Jujuy, has been estimated in 0,9%. Blood Transfusion (BT) as a risk factor for developing TSP/HTLV-1 has been already documented. Objective: To evaluate the risk of developing TSP among transfusion recipients. Methods: In a retrospective study a total of 45 females, 15 (31%) with a history of BT and 30 (69%) without (NBT) were evaluated for the presence of signs and symptoms of TSP. All serum samples tested positive for HTLV-I/II antibodies by PA technique and were further confirmed by the IFA. HTLV-I was suggested in all cases by IFA differential titration using MT-2 and MO-T cell lines. All patients were HIV negative, and other risk factors such as intravenous drug abuse or promiscuity was not found. Results: The median age was 51 and 48 years old for the BT and NBT group respectively. TSP was diagnosed in 86% (13/15) of patients from the BT group and in 42% (15/30) from the NBT group. This difference was found to be significative OD: 6.5, p<0,04. In the BT group, 75% (9/12) of the patients presented, spasticity within 5 years after their transfusion. In the NBT group this was observed in 33% (3/9) of the patients. OD: 9, p <0,05. Conclusions: The risk of developing TSP/HTLV-1 was found to be higher for the transfused patients. The presentation of the typical clinical picture is shorter than 5 years after been transfused. The severety of the discapacity according to Osame score was no related to blood transfusion.

HIGH SEROPREVALENCE OF HTLV-1 AMONG CHILDREN AND PREGNANT WOMEN INHABITANTS OF THE HIGH LANDS FROM JUJUY. ARGENTINA.

P096 Introduction: The seroprevalence of HTLV-I infection among blood bank donors in Jujuy province has been estimated in 0.9%. These seropositivity was found to be higher among females and to increase with age. Objetive: In order to investigate the geographic distribution of HTLV-I seroprevalence among inhabitants groups from high lands of Jujuy a seroepidemiological survey was conducted. Method: A total of 1456 children aged between 18 months and 11 years and 335 pregnant women from La Puna, Quebrada, Valle and Ramal areas were included in the present study. Specimens were tested for the presence of HTLV-I/II antibodies by the PA technique. Positive samples were confirmed by the IFA assay. Results:(Table)TableConclusions: These places with higher prevalence are located over 2.500mosl, the majority are amerindians descendants, living in remote places where migration rate is low and inbreeding index is high. The finding of HTLV-I infection among children suggests transmission of the virus by prolonged breast feeding.

Evaluation of a recombinant protein(rTc24) and synthetic peptides in anti-Trypanosoma cruzi positive samples from blood bank donors in chagasic endemic areas of ecuador.

Evaluation of a recombinant protein(rTc24) and synthetic peptides in anti-Trypanosoma cruzi positive samples from blood bank donors in chagasic endemic areas of ecuador.

A simple Trypanosoma cruzi enzyme-linked immunoassay for control of human infection in nonendemic areas

An enzyme linked immunosorbent assay (ELISA) was developed for detecting IgM and IgG antibodies against Trypanosoma cruzi in blood bank donors from endemic or nonendemic areas. A crude extract of trypomastigotes from cultures was used as antigen. A total of 494 serum samples from patients with acute, congenital, or chronic form of Chagas' disease, and from healthy French individuals were studied. The sensitivity of the ELISA was determined with 89 serum samples from chagasic patients and was evaluated to 98.8%. The specificity was determined with 405 serum samples from French blood transfusion centers donors and evaluated to 98.3%. Two hundred and eighty-five serum samples from blood donors from Argentina and Brazil were also tested. Furthermore, in order to assess the absence of cross-reactivity with other protozoan infections, we studied 86 serum samples including (i) 32 individuals with cutaneous leishmaniasis living in a T. cruzi endemic region of Bolivia, and (ii) 54 patients from nonendemic area for Chagas' disease, 19 of them with kala-azar and 35 others with malaria.