[Serotypes of the human immunodeficiency virus type 1 in Madrid]. / Serotipos del virus de la inmunodeficiencia humana tipo 1 en Madrid.

BACKGROUND: HIV-1 shows high genetic variability, mainly in the genomic region codifying the envelope proteins, which are the most immunogenic. This fact explains the high heterogeneity of antibodies against HIV-1 epitopes. Both genetic and serologic diversity has allowed to classify HIV-1 variants in several subtypes (genotypes and serotypes, respectively). The clinical and epidemiological significance of infection caused by each subtype remains to be clarified. PATIENTS AND METHODS: Serum samples from 154 HIV-seropositive individuals living in Madrid were studied. Serotyping was performed using 4 peptides belonging to the V3 env region. Epidemiological and clinical variables examined in these patients were the route of infection, the year in which HIV infection occurred, the country of birth, and the rate of disease progression (rapid versus slow). RESULTS: 148 (96.2%) samples could be serotyped, and the B class was recognized in 131 (88.5%) of them. Serotype A/C was found in 9 (6.1%). Two samples (1.3%) reacted to peptide E; however, both were also reactive against the B peptide, suggesting co-infection with B and E subtypes. Six samples were EIA-reactive for HIV-1/2 but were typed as HIV-2 alone. Infection with serotypes A/C was more frequent amongst immigrants, mainly in Africans. There was not association between any subtype and the route of infection neither a different rate of disease progression. CONCLUSION: HIV-1 serotype B is the most frequently found in HIV-seropositive individuals living in Madrid, without association with the route of infection or the clinical course of the disease. Serotypes A/C and E were found sporadically, mainly among immigrants.

Epidemiology of human T-lymphotropic virus type II (HTLV-II) infection in Spain. HTLV Spanish Study Group.

The human T-lymphotropic virus type II (HTLV-II) has recently been associated with the genesis of some subacute neurological syndromes and, rarely, with atypical T-lymphoid malignancies. The virus is endemic in some Amerindian and African tribes, and among intravenous drug users (IDUs) in North America and Europe. Given that HTLV-II is transmitted by the same routes as other human retroviruses, the screening of antibodies to HTLV-II in blood donors has became a matter of controversy in some countries. Herein, we describe the clinical, epidemiological and virological features of 113 individuals with HTLV-II infection identified in Spain up to September 1995. Most of them (94/113; 83%) were male, and all but seven were natives. Four were African immigrants living in Madrid and 3 had been born in other European countries. All but six subjects were IDUs, and sexual transmission of HTLV-II and transfusion were involved in five and one individual, respectively. Eighty-four percent of the IDUs infected with HTLV-II were co-infected by HIV-I (93/107). Clinical manifestations potentially linked to HTLV-II were absent, although an IDU male co-infected by HIV-1 and HTLV-II developed a severe non-inflammatory proximal myopathy. In conclusion, HTLV-II infection is present in Spain, mainly among IDUs, with a growing incidence and a current overall prevalence of 2.0 percent.

Comparison of immunofluorescence with enzyme immunoassay for detection of Q fever.

To evaluate enzyme immunoassay (EIA) as an alternative to indirect immunofluorescence assay (IFA) to screen for Q fever in humans, 157 serum samples from patients suspected of having the disease were tested for immunoglobulin G antibodies to Coxiella burnetii. The agreement between the tests and the sensitivity of EIA were excellent (96.8% and 98.4%, respectively) when an IFA titer of > 1/160 was considered positive. All serum samples with a titer of > 1/320 in the IFA were also positive by the EIA. The EIA seems to be an acceptable alternative to IFA for screening for Q fever.

[the early diagnosis of the vertical transmission of the human immunodeficiency virus type 1. The evaluation of diagnostic tests]. / Diagnóstico precoz de la transmisión vertical del virus de la inmunodeficiencia humana tipo 1. Valoración de las pruebas diagnósticas.

BACKGROUND: The early diagnosis of vertically transmitted human immunodeficiency virus infection cannot be based on the presence of specific serum antibodies since those of the maternal IgG class pass the placenta and may be detected in children for up to 18 months. Based on this fact, the aim of this study was to evaluate other techniques for early diagnosis of the infection applicable from birth in 306 children of infected mothers. METHODS: The production of in vitro antibodies, virus culture and polymerase chain reaction (PCR) were used. The sensitivity of the techniques was estimated in the 40 children diagnosed with human immunodeficiency virus infection and specificity was determined in the 266 uninfected children. RESULTS: The sensitivity for the production of in vitro antibodies was 62.0% at 3 months and 94.7% at 6 months; 90.4% and 88.2%, respectively, for the viral culture and 92.3% and 94.1%, respectively, for the PCR. The specificity of all the cases was higher than 89.4% although varied in relation to age. CONCLUSIONS: The combination of several diagnostic techniques provides better performance for the early diagnosis of vertical transmission of the human immunodeficiency virus. Given that viral culture takes longer to provide results and is more expensive, it is less recommendable for routine use, although the form of viral replication may be useful to establish the prognosis.

Prognostic value of immunological data, in vitro antibody production, and virus culture in vertical infection with HIV-1.

The prognostic value of immunological indices, in vitro antibody production, and virus culture pattern at 3 months of age was estimated in 35 infants infected by HIV-1 from a cohort of 298 babies born to HIV-1 seropositive mothers and followed up from birth. At 1 year old, 15 of these infants were classified as stage P-1 (according to the Centers for Disease Control classification) seven were P-2A, and seven had AIDS. Significantly higher CD8 percentages, lower percentages and absolute value of CD4, and lower CD4/CD8 ratios at 3 months were observed in infants with severe symptoms at 1 year of age when compared with those who were asymptomatic at this age. Seventy seven per cent of infants with a 'rapid' virus culture when 3 months old had developed AIDS or had died by 1 year of age and only 8% of those with 'slow' virus culture had AIDS when 1 year old. Moreover, 100% of those who were asymptomatic at 1 year had a slow virus culture at 3 months. Significant statistical association was found between the virus replication pattern at 3 months and the clinical stage at 1 year of age.

Evidence of hepatitis C virus antibodies in the cryoprecipitate of patients with mixed cryoglobulinemia.

OBJECTIVE: To describe the clinical features of 8 patients with mixed cryoglobulinemia and hepatitis C virus (HCV) infection. METHODS: A clinical study of the patients was performed. Anti-HCV antibodies were determined by ELISA and confirmed by immunoblot (RIBA) in the sera and in the cryoprecipitate. RESULTS: All patients had liver dysfunction, while most had arthralgias and/or arthritis, purpura, peripheral nervous system involvement and renal disorders. Cryocrits ranged from 1 to 6%. Six patients had type III mixed cryoglobulinemia and the remaining 2 had type II. History of blood transfusion was recorded in 2 patients. Hepatitis B virus (HBV) markers were negative in all sera samples. The cryoprecipitate of 7 patients was negative for HBV markers, but anti-HCV antibodies were positive by both ELISA and RIBA. CONCLUSION: After reviewing published reports and discussing the possible role that hepatitis C virus plays in the pathogenesis of mixed cryoglobulinemia, we conclude that HCV may stimulate immune complex formation and produce cryoglobulinemia. Therefore its investigation is recommended before the diagnosis of "essential" mixed cryoglobulinemia is established.

[Evaluation of various criteria for the interpretation of western blot for the diagnosis of human immunodeficiency virus infection. Spanish Group for the Study of HIV-2]. / Evaluación de diferentes criterios de interpretación del Western blot para el diagnóstico de la infección por el virus de la inmunodeficiencia humana. Grupo Español para el Estudio del VIH-2.

BACKGROUND: The Western blot (WB) is the most commonly used test to confirm the presence of antibodies against the human immunodeficiency virus type 1 (HIV-1). Different criteria of interpretation of the band profile have been proposed with there being no unanimity as to its reliability. The sensitivity and specificity of several criteria proposed for the interpretation of WB were evaluated and the individual significance of the reactivity of each band of the WB was analyzed. METHODS: The presence of antibodies against HIV-1 was prospectively studied in 8,073 samples of subjects with risk of infection. A total of 1,993 (25%) were reactive by ELISA and 1,261 were analyzed by WB, with a semiquantitative reading of the bands with a point scale from 0 to 2 being performed. The final interpretation of the WB (negative, doubtful, or positive) was carried out following 5 recommendations of usage. A test designed with synthetic peptides (Pepti-lav) was used as a reference and in discordant cases, other more specific serologic tests and/or genetic analysis by polymerase chain reaction (PCR) were performed. RESULTS: In order of frequency, the greater sensitivity was found to be for the CRSS (Consortium for Retrovirus Serology Standardization) criteria (97.9%), OMS (96.6%), CDC (Center for Disease Control) (95.9%), ARC (American Red Cross) (95.6%) and FDA (99.8%). The greatest specificity was for the criteria of the OMS, and FDA (99.8%). In order of frequency, the most frequent bands in HIV-1 + individuals were gp160 (99%), gp120, p24, p31, p55, p68, gp41, and p17 (68%). In non infected individuals, the recognized bands were, in decreasing order, p24, p17, p55, p68, p31, and glucoproteins. CONCLUSIONS: Different criteria of interpretation of the Western blot provide different degrees of sensitivity and specificity. The Western blot is a non standardized, expensive, laborious technique of subjective interpretation which provides an appreciable number of undetermined results.

[A multicenter study of infection with human immunodeficiency virus type-2 (HIV-2) in Spain (1991). The Spanish Group for the Study of HIV-2]. / Estudio multicéntrico de la infección por el virus de la inmunodeficiencia humana tipo 2 (VIH-2) en España (1991). Grupo Español para el Estudio del VIH-2.

BACKGROUND: To January 1991 thirteen cases of HIV-2 infection had been reported in Spain. Paradoxically, neighboring countries, i.e. France and Portugal, have reported more than one thousand cases, and are the most HIV-2 prevalent areas outside West Africa. We report the results of a prospective, nationwide study on the prevalence of HIV-2 infection conducted in Spain in 1991. In addition, an evaluation of testing methodologies is made. METHODS: Sera collected from 8,073 individuals at high-risk for HIV infection were screened by a combined HIV-1 plus HIV-2 ELISA. Reactive samples were further evaluated by three tests, as HIV-1 Western blot (WB), HIV-2 specific WB, and a synthetic peptide assay immuno-dot (Pepti-lav, Pasteur). RESULTS: Fifteen (0.18%) individuals met criteria of HIV-2 infection in both specific WB and SPA. Four (27%) of them showed reactivity to both HIV-1 and HIV-2, and the dual infection was confirmed by polymerase chain reaction (PCR) in 2 out of 3 available samples. The SPA showed higher sensitivity and specificity than WB in the diagnosis and distinction of HIV-1 and HIV-2 infections. CONCLUSIONS: To January 1992, 28 cases of HIV-2 infection have been described in Spain. All but two were African immigrants. The first cases of HIV-1 plus HIV-2 coinfection have been identified. In HIV high-risk populations, SPA may provide an excellent alternative to WB to confirm ELISA reactive samples.

[Evaluation of IgG-IgM antibodies against the Epstein-Barr virus nuclear antigen (EBNA-1) using ELISA]. / Estudio y valoración de anticuerpos IgG-IgM frente al antígeno nuclear del virus de Epstein-Barr (EBNA-1) mediante ELISA.

BACKGROUND: Evaluation of two commercial immunoenzymatic techniques (ELISA) for detection of anti-EBNA-1 IgG and IgM for diagnosis of Epstein-Barr virus mononucleosis. METHODS: Study of anti-EBNA-1 IgG and IgM in infectious mononucleosis and they have been compared with the detection of IgM antibodies to VCA by indirect immunofluorescence as the reference method. RESULTS: The sensitivity of the assay was 87.5%, the specificity was 89.4%, the positive predictive value was 91.4% and the negative predictive value was 85%. CONCLUSIONS: This technique can be useful in laboratories without the necessary equipment and experienced personnel for indirect immunofluorescence. It also can be used as a complementary determination to the anti-VCA IgM in the long lasting infectious mononucleosis, when this marker is negative.

[Long-term follow-up study of 35 children with ADS treated with zidovudine (AZT)]. / Estudio evolutivo de 35 niños afectos de síndrome de inmunodeficiencia adquirida (SIDA) en tratamiento con Zidovudina (AZT).

Thirty-five children diagnosed of AIDS were studied in order to evaluate toxicity and efficacy of oral Zidovudine treatment (AZT), as well as to analyze the clinical, biochemical, immunological and virological evolution of HIV infection throughout the treatment. Patients (19 males and 16 females) were studied from April 1988 to May 1990 with a mean follow-up time of 13.5 months (SD = 6.7 months). The mean age of the group was 4.68 years. The means of acquisition of this disease was 71.45 vertical and 28.6% via hemo-derivatives. Tolerance has been good with the main toxicity being hematological (28.5% anemia and/or neutropenia), 23% of which required blood supplements. The presence of neurological involvement and thrombopenia were observed in the incidence of greater toxicity. No influence on weight during AXT treatment was observed and hepatosplenomegalia and adenopathies were not modified. Bacterial and opportunistic infections were observed in 97.1% and 20% of patients, respectively. Neurological evolution was irregular and the improvement observed in some patients was mild and transitory. Three patients died during the follow-up from intercurrent infectious process. A progressive increase in MCV and a tendency towards leucopenia and lymphopenia (mainly in hemo-derivative infected patients) was observed. Neither significant immunological nor virological changes were observed during the treatment (except the tendency to diminish basal hypergammaglobulinemia). The results of this study were compared to other pediatric series treated with AZT.

Prevalence of hepatitis C antibodies (HCV) in a dialysis population at one center.

Hepatitis C (HC) has been recently diagnosed by determination of specific antibodies that represent the former so-called non-A, non-B hepatitis. We studied the prevalence of plasma HCV antibodies among 61 unselected patients on hemodialysis (HD) and 43 on continuous ambulatory peritoneal dialysis (CAPD). Plasma C-antibodies were determined through the ELISA test system. Transfusion policy was the same in both groups. The prevalence of hepatitis C virus antibodies was significantly higher in hemodialysis patients than among those on CAPD. Time on dialysis, previous blood transfusions, and renal transplantation seem to increase the prevalence of C hepatitis antibodies among hemodialysis patients. The effect of these parameters on CAPD was smaller. Understanding the reasons for these differences may help prevent this disease among dialysis patients.