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Separate studies investigating the relationship of essential hypertension (EH) with the HLA system and with Chlamydia pneumoniae (C. pneumoniae) infection have given conflicting results. Our aim was to clarify these relationships and determine whether the HLA system and C. pneumoniae infection interact with respect to the risk for EH. An association study (110 essential hypertensives and 107 controls) was conducted in a highly homogeneous population in the Balearic Island of Majorca (Spain). Molecular typing of HLA-B and HLA-DRB and quantification of serum levels of IgG antibodies to C. pneumoniae (sIgGa-Cp) were determined. Student's t-test, chi(2)-statistics, logistic regression analysis, and general linear model ANOVA were used for statistical analysis. The results showed that EH was related with HLA-DRB3*0202 in the whole study population, and with levels of sIgGa-Cp>63.5 BU/ml in the group of individuals with sIgGa-Cp>30 BU/ml (OR (95% CI) adjusted for obesity, familial history of EH and diabetes=2.06 (1.07-3.97), P=0.03, and =4.60 (1.06-19.90), P=0.04, respectively). The association between EH and sIgGa-Cp was observed in the DRB3*0202(+) individuals, but not in the DRB3*0202(-) subgroup (OR (95% CI)=11.14 (1.92-64.54), P=0.004, and =0.98 (0.22-4.43), P=0.64, respectively (P of the Mantel-Haenszel test for homogeneity of OR=0.06)). In our population, EH was positively associated with HLA-DRB3*0202 and with high levels of sIgGa-Cp. Moreover, a significant interaction of DRB3*0202 on the effect of sIgGa-Cp was observed, as the association of EH with these antibodies depended on the presence of DRB*0202.

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Numerous association studies have been performed to evaluate the relationship between the angiotensinogen gene and the essential hypertension, but their results are conflicting. The conflicting results may be explained by methodological reasons, particularly genetic differences in the population samples, phenotypic differences in the hypertensive populations analyzed, lack of appropriate control for other hypertension risk factors in some studies, or limited statistical power among many studies. Furthermore, hypertension is a public health issue of great relevance in Baleric Islands (Spain). For these reasons we performed an association study about the relationship between the M235T, T174M and G-6A diallelic polymorphisms of the angiotensinogen gene and hypertension in a population from Majorca (Balearic Islands), in which a considerable homogeneity with respect to ethnicity and environmental factors could be documented. This population was composed of 109 patients and 107 controls. Alleles of the angiotensinogen gene were determined by PCR and restriction site polymorphism analysis. The different genotypes were tested for association with dependent variables by univariate and multivariate logistic regression analysis. In the univariate analysis we found no evidence of association between the angiotensinogen gene genotypes and hypertension. This lack of association was independent of obesity, familial history of hypertension and diabetes for the genotypes of the polymorphisms M235T and G-6A; however, in the multivariate analysis the T174T174 genotype showed an almost significant positive association with hypertension [OR = 2.76 (95% confidence interval: 1.00-7.65, p = 0.05)]. The T174T174 genotype also showed a significant negative association with obesity [OR = 0.41 (95% confidence interval: 0.18-0.90, p = 0.03)] that remained after adjustment by sex, hypertension and diabetes [OR = 0.26 (95% confidence interval: 0.10-0.65, p = 0.004)]. Our results: a) are in contrast with the results from most previous studies that found a relationship of the T174M polymorphism with hypertension, as in those studies the M174 allele was responsible for the association; b) emphasize the need for rigorous control for obsesity in the studies of association between the angiotensinogen gene and hypertension; c) underscore the importance and the utility of using concrete populations to carry out studies on the genetic dissection of hypertension.

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INTRODUCTION: Synthesis of IgG is useful data for the diagnosis of multiple sclerosis, and different formulas, both direct and indirect, are used to quantify this. We analyze these formulas with the objective of finding whether certain combinations of them would give better results than the individual formulas on their own. PATIENTS AND METHODS: We studied the cerebrospinal fluid of 45 patients with neurological disorders and determined the results of the two formulas which are most effective, according to some studies (Reiber's formula and IgG index) together with a direct formula (IgG ratio) and another indirect formula (the 'classical' formula of Tourtellotte). RESULTS: The IgG index was, in general, the formula which best differentiated between patients with multiple sclerosis and persons with other neurological disorders. CONCLUSIONS: We found a tendency which supported the original hypothesis that it is possible to use combinations of formulas to obtain better results than individual formulas. This fact may serve as a basis for further studies in which different combinations are tested, including analytical and clinical data, and this may be of use in the diagnosis of multiple sclerosis.

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OBJECTIVE: To identify subsets of CD4 T lymphocytes that can predict the development of AIDS and to assess whether increased levels of these cellular markers could provide additional independent prognostic information to the CD4 T cell count and plasma HIV-1-RNA levels. DESIGN AND METHODS: In a prospective study, a cohort of 85 HIV-positive intravenous drug users [clinical categories of the CDC classification A (n = 48) and B (n = 37)] were followed for a period of 37+/-13 months. Memory and activated CD4 and CD8 T cells were quantitated by three-colour flow cytometry at baseline and expressed as a percentage of total CD4 and CD8 lymphocytes. Clinical evaluations were performed at 6 month intervals. The relationships between these lymphocyte subsets and progression to AIDS were studied using Kaplan-Meier plots and proportional hazards regression models. RESULTS: After adjustment for the level of CD4 T cells and plasma HIV-1-RNA levels, the elevation in the subset CD4+CD38+DR+ was the marker within the functionally distinct subsets of CD4 T lymphocytes with additional prognostic value in bivariate Cox regression models. In multivariate models, increased percentages of CD4+CD38+DR+ T cells provided the strongest independent prognostic information for progression to AIDS (relative hazard, 1.07; P < 0.0001). CONCLUSION: Our results suggest that high levels of CD4+CD38+HLA-DR+ T cells reflect the increasing degree of CD4 T cell activation during the progression of HIV infection, and could be used together with the CD4 T cell and HIV-RNA levels to evaluate more accurately the progressive cellular immune impairment associated with the risk of progression to AIDS.

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We have performed a prospective study to determine the prevalence of immunological abnormalities and the evolution from primary antiphospholipid syndrome (APS) into systemic lupus erythematosus (SLE) in women who had had unexplained repeated pregnancy loss (PL) and APS. Of 105 women with abortions or fetal deaths, 33(31%) fulfilled criteria for APS. Among these patients with primary APS, 24% had antinuclear antibodies (ANA), 91% had elevated circulating immune complexes (CIC), 70% had low total haemolytic complement (CH100), 52% had low levels of complement 4 (C4) and 30% had low levels of complement 3 (C3), in a significantly higher prevalence than women whose pregnancies were successful (control group). Through out a 6 y follow-up, 3 (9%) of the patients with APS who had autoimmune related abnormalities when entered into the study developed features of lupus like disease (LLD) or fullblown SLE. Our findings suggest that women with unexplained repeated PL with APS who presented with positive ANA, high levels of CIC, low levels of CH100, C3 and C4, may define a subset of patients exhibiting immunological alterations similar to those of SLE. These parameters may help in the assessment of prognosis in APS patients with PL. Those patients should be carefully surveyed with regard to the development of connective tissue diseases.

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We determined the representation in asymptomatic human immunodeficiency virus (HIV) infection of the CD45RO+ and CD45RO- CD45RA+ subsets of CD4+ and CD8+ T lymphocytes, CD11b+ and CD11b- subsets of CD8+ T cells, and activated populations of these subsets. Three-color flow cytometry was used to quantitate the different CD4+ and CD8+ T cell populations in 116 asymptomatic HIV+ individuals. In asymptomatic HIV+ infection there was a significant relative increase in the CD4+ CD45RO+ and CD8+ CD45RO+ T cell subsets, which express CD38 and DR antigens, that correlated strongly with the decline in total CD4+ T cells. In addition, we found a loss of CD4+ CD45RO- and CD8+ CD45RO- T cells associated with progression of HIV infection (as measured by the decline in total CD4+ T cells). Studies presented here also indicate that, with the progression of asymptomatic HIV infection, CD8+ CD11b- T lymphocytes showed a significant decrease, whereas CD8+ CD11b+ T cells were significantly increased. This study demonstrates that the progression of HIV infection in asymptomatic patients involves the increase in CD45RO+ subsets of CD4+ and CD8+ T cells, the increase in CD8+ CD11b+ T cells, the decrease in CD45RO- CD45RA+ subsets of CD4 and CD8 T cells, and the decline in CD8+ CD11b- T cells.

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A nested PCR was used to quantify small numbers of human immunodeficiency virus (HIV) type 1 (HIV-1) RNA particles in the serum specimens of 26 p24 antigen-negative, asymptomatic, HIV-positive patients undergoing antiretroviral therapy. Fifteen patients received zidovudine (ZDV) and alpha interferon, and 11 patients received ZDV monotherapy. After PCR, the amounts of RNA were quantified by comparing the endpoint dilutions of serum samples with a standard curve with known amounts of viral particles. Before the beginning of the antiviral therapy, HIV-1 RNA was detected in 92% of the patients. After treatment, a fall in the number of viral particles was detected in patients receiving combination therapy (mean titers +/- standard errors of the means, 3,617 +/- 756 pretherapy versus 1,800 +/- 845 posttherapy; P < 0.05) and in patients receiving monotherapy (3,763 +/- 642 pretherapy versus 1,353 +/- 394 posttherapy; P < 0.05). Our results indicate that PCR with nested primers may be useful for assessing the changes in viremia in HIV-positive patients with low viral load undergoing antiviral therapy.

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Several immunological and serological variables have become established in recent studies as valuable markers to identify human immunodeficiency virus (HIV)-positive individuals at the highest risk for rapid disease progression. These studies have been performed mainly in cohorts of homosexual men. In this study, we assessed the usefulness of CD4 lymphocyte count, serum beta 2-microglobulin concentration, and the presence of p24 antigen as predictors of AIDS in a cohort of 130 HIV-positive injection drug users (IDUs) followed-up for 1 to 67 months. Progression to AIDS was most strongly associated with reduced absolute numbers of CD4+ lymphocytes at baseline, but increases in beta 2-microglobulin levels at baseline were an independent predictor of outcome. After stratification by baseline CD4 count, beta 2-microglobulin concentration added significant prognostic information to CD4 count among IDUs with > 500/mm3 CD4 cells (Breslow statistic value, 5.84, p = 0.01). Thus among seropositive IDUs with normal CD4 counts, increases in beta 2-microglobulin may be used as an early marker of individuals with higher risk of progression to AIDS, who may benefit from more intensive laboratory monitoring or clinical management.

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We analyzed the in vitro synthesis and release of PGE2, IL-1 beta, and TNF-alpha by peripheral blood monocytes from HIV-infected injection drug users at the early clinical stages of HIV infection. We investigated whether there is a concomitant altered production of PGE2 and proinflammatory cytokines by HIV-positive monocytes. We also evaluated T-cell subsets and lymphocyte transformation response to pokeweed mitogen (PWM) in HIV-positive patients and healthy controls. PGE2 and IL-1 beta levels in supernatants from monocyte cultures were determined by radioimmunoassay (RIA), and TNF-alpha by enzyme immunoassay (EIA). Monocytes from asymptomatic HIV-positive individuals produced spontaneous and significantly increased quantities of PGE2, IL-1 beta, and TNF-alpha. Concomitant increased production of PGE2 and IL-1 beta by monocytes from HIV-positive asymptomatic patients was significantly associated with low CD4+ T-cell numbers (< 500 cells/mm3). We also found a strong association between spontaneous and concomitantly increased production of PGE2 and cytokines by monocytes from asymptomatic HIV-positive individuals and a low lymphocyte transformation response to PWM. Further studies are necessary to establish whether this altered production of PGE2 and proinflammatory cytokines by monocytes from HIV-positive individuals might play a role in the mechanisms involved in the progressive impairment of cell-mediated immunity in HIV infection.

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Prostaglandin E2, thromboxane B2 and leukotriene B4 monocyte production have been determined in human immune deficiency virus (HIV)-infected drug users (n = 36) and healthy subjects (n = 29). Eicosanoids were extracted from the incubates using C18 solid-phase cartridges and determined by radioimmunoassay. An enhanced production of prostaglandin E2 and thromboxane B2 was detected in monocytes from HIV-positive drug users whether or not they had been previously stimulated with zymosan. Concomitant leukotriene B4 increases were not observed. The results reported in this paper indicate that altered cyclooxygenase arachidonic acid metabolism in monocytes from HIV-infected drug users is associated with the severe cellular immunodysfunction characteristic of AIDS. In contrast, leukotriene B4 does not seem to play a role in AIDS-associated immunosuppression.

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We have performed a prospective 33-month follow-up of the evolution of HIV infection in a cohort of 76 HIV-positive intravenous drug users (IVDUs). We report on immunological and serological variables that proved to be highly predictive of development to AIDS. In a stepwise multivariate analysis of the actuarial progression rate we found the number of CD4+ lymphocytes to be the most powerful predictor of progression to AIDS. We found no independent predictive effects associated with any other variable with predictive power: loss of antibody to p24 antigen, anergy, HIV p24 antigenaemia, loss of antibody to p53 (reverse transcriptase), decreased number of CD8+ T cells, loss of antibody to p31, loss of antibody to p17, beta 2-microglobulin level, loss of antibodies to gp41 and p64, or immunoglobulin A level. We have found that our data differ from those obtained in studies in homosexual men in the different prognostic value of those predictive markers. Our findings should help to identify high risk of progression to clinical AIDS among IVDUs, thereby assisting in the selection of patients for prophylaxis and therapy.

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We have studied immunological, serological and clinical abnormalities in 264 HIV-positive and HIV-negative drug abusers. Ninety percent of the 264 drug addicts (mean age 26 +/- 0.8 years) were found to have HIV antibodies and there was a significant increase (P less than 0.01) in the frequency of HIV antibody positivity with increasing duration of exposure to parenteral drug abuse. There was a very strong correlation between the progressive decline of the mean T4+ helper/inducer cells and T4+/T8+ ratio, the low response to pokeweed mitogen and the more severe clinical manifestations of HIV infection. Impairment of delayed-type hypersensitivity reaction to recall antigens was only seen in group IV as defined by the Center for Disease Control. Within group IV, anergy was found to be highly associated (83%) in patients with opportunistic infections. All other HIV-positive addicts from groups II and III, as well as HIV-negative addicts had normal in vivo responses to test antigens. We have also analysed in a prospective follow-up lasting 6-24 months, the evolution of HIV infection in a cohort of 50 HIV-antibody-positive drug addicts. Thirty-two percent showed clinical progression and most of the drug addicts that proceeded to full-blown AIDS developed anergy (82%) prior to clinical deterioration with development of opportunistic infections. We conclude, that in seropositive drug addicts a low absolute count of helper/inducer cells (mean +/- s.e. = 243 +/- 48 cells/mm3), a low response to pokeweed mitogen and anergy are predictive markers of progression to AIDS.

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Two cases of severe combined immunodeficiency (SCID) with normal numbers of T cells are reported. Studies of T-cell subsets showed an absence of TQ1+ lymphocytes and a very low percentage of CD4+ cells in Patient 2. Functional studies of T cells from this patient showed a normal suppressor activity. Patient 1 had normal percentages of T-cell subsets and his lymphocytes showed helper and suppressor activities but to a lesser degree than normal controls. Both cases stressed the heterogeneity of SCID in which T cells could be present and retain some of their functional activities.

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