Association between airborne pollen and epidemic asthma in Madrid, Spain: a case-control study.

BACKGROUND Despite the fact that airborne pollen is an important factor in precipitating asthma attacks, its implication in increases of epidemic asthma in usual meteorological conditions has not been reported. A study was undertaken to estimate the relationship between various types of aeroallergens and seasonal epidemic asthma in the region of Madrid, Spain. METHODS A case-control study was carried out in individuals aged 4-79 years who received emergency healthcare for asthma during 2001 in a base hospital covering a population of 750 000 inhabitants of Madrid. A skin prick test was performed with grass pollen, plantain pollen, olive pollen, cypress pollen, plane tree pollen, dust mites and Alternaria and the prevalence of skin reactivity was compared between subjects with asthma requiring emergency care for asthma within (cases) and outside (controls) the seasonal epidemic period. Data were analysed using logistic regression adjusting for age and sex. RESULTS The response rate was 61.7% for cases (n=95) and 51.6% for controls (n=146). The OR of sensitisation to grass pollen for cases compared with controls was 9.9 (95% CI 4.5 to 21.5); plantain pollen: 4.5 (95% CI 2.5 to 8.2); olive pollen: 7.3 (95% CI 3.5 to 15.2); plane tree pollen: 3.6 (95% CI 2.0 to 6.4); cypress pollen: 3.5 (95% CI 2.0 to 6.2); dust mites: 1.1 (95% CI 0.6 to 1.9); Alternaria: 0.9 (95% CI 0.5 to 1.9). The association with grasses was maintained after adjusting simultaneously for the remaining aeroallergens (OR 5.0 (95% CI 1.5 to 16.4)); this was the only one that retained statistical significance (p=0.007). CONCLUSIONS These results suggest that allergy to pollen, particularly grass pollen, is associated with the epidemic increase in asthma episodes during the months of May and June in the Madrid area of Spain.

The CD4/CD8 ratio as a marker T-cell activation, senescence and activation/exhaustion in treated HIV-infected children and young adults.

We explored the associations of the CD4/CD8 ratio with markers of immunoactivation, immunosenescence and T-cell subsets, in 37 vertically HIV-infected children and adolescents. CD4/CD8 ratio inversion was associated with higher frequencies of activated, senescent and activated/exhausted CD4+ and CD8+ T-cells, and a skewed T-cell phenotype from naive toward effector memory which persisted after the multivariate analysis. Thus, the CD4/CD8 ratio may identify patients with higher immunoactivation despite ART.

High drug resistance prevalence among vertically HIV-infected patients transferred from pediatric care to adult units in Spain.

BACKGROUND: Antiretroviral treatment (ART) has contributed to increased life expectancy of HIV-1 infected children. In developed countries, an increasing number of children reaching adulthood are transferred to adult units. The objectives were to describe the demographic and clinical features, ART history, antiviral drug resistance and drug susceptibility in HIV-1 perinatally infected adolescents transferred to adult care units in Spain from the Madrid Cohort of HIV-1 infected children. METHODS: Clinical, virological and immunological features of HIV-1 vertically infected patients in the Madrid Cohort of HIV-infected children were analyzed at the time of transfer. Pol sequences from each patient were recovered before transfer. Resistance mutations according to the InternationaI AIDS Society 2011 list were identified and interpreted using the Stanford algorithm. Results were compared to the non-transferred HIV-1 infected pediatric cohort from Madrid. RESULTS: One hundred twelve infected patients were transferred to adult units between 1997 and 2011. They were mainly perinatally infected (93.7%), with a mean nadir CD4+-T-cells count of 10% and presented moderate or severe clinical symptoms (75%). By the time of transfer, the mean age was 18.9 years, the mean CD4+T-cells count was 627.5 cells/ml, 64.2% presented more than 350 CD4+T-cells/ml and 47.3% had ≤ 200 RNA-copies/ml. Most (97.3%) were ART experienced receiving Highly Active ART (HAART) (84.8%). Resistance prevalence among pretreated was 50.9%, 76.9% and 36.5% for Protease Inhibitors (PI), Nucleoside Reverse Transcriptase Inhibitors (NRTI) and Non-NRTI (NNRTI), respectively. Resistance mutations were significantly higher among transferred patients compared to non-transferred for the PI+NRTI combination (19% vs. 8.4%). Triple resistance was similar to non-transferred pediatric patients (17.3% vs. 17.6%). CONCLUSION: Despite a good immunological and virological control before transfer, we found high levels of resistance to PI, NRTI and triple drug resistance in HIV-1 infected adolescents transferred to adult units.

Detectable viral load aggravates immunosenescence features of CD8 T-cell subsets in vertically HIV-infected children.

BACKGROUND: CD8 T cells are crucial in the immune responses against HIV infection, but HIV-infected adults suffer a naive CD8 T-cell depletion and accelerated senescence caused by chronic antigen stimulation. Although HIV-infected children preserve a better immune reconstitution capacity their CD8 responses are defective. We wanted to know, whether HIV vertical transmission produces a premature aging of the CD8 population due to antigen exposition to HIV from birth and persistent chronic activation. METHODS: We conducted a multicentre cross-sectional study that compared vertically HIV-infected children with detectable (viremic) or undetectable (aviremic) viral load and age-matched healthy children. Using multiparameter flow cytometry, we studied within the CD8 population the frequencies of naive, memory, effector memory (effector memory), and TemRA subsets and measured markers of senescence, activation, and proliferation in these cells. RESULTS: We found that naive subset in viremic children was markedly decreased and had a replicative senescence phenotype. Furthermore, viremic children showed increased frequencies of memory, TEM and TemRA CD8 T cells, with a more activated and replicative senescence phenotype. We found that HIV-infected children with undetectable viral load have an increased senescence in memory and effector CD8 T cells, but the frequencies and phenotype of the CD8 subsets analyzed are comparable to healthy children. CONCLUSIONS: [corrected] Our study shows that CD8 T cells of HIV-infected children have a more senescent phenotype when compared with age-matched healthy children. Interestingly enough, our results support the importance of maintaining undetectable viral load in HIV-infected children to avoid the premature ageing and dysfunction of CD8 T cells.

Impact of highly active antiretroviral therapy (HAART) on AIDS and death in a cohort of vertically HIV type 1-infected children: 1980-2006.

We evaluated the population effectiveness of highly active antiretroviral therapy (HAART) on the risk of AIDS and death in a multicenter cohort of 346 HIV-1 vertically infected children born between 1980 and 2006 in the Comunidad Autónoma de Madrid (CAM), Spain. Risks of AIDS and death in patients with the same duration of HIV infection were compared in different calendar periods [CP1: 1980-1989, CP2: 1990-1993 (reference), CP3: 1994-1996, CP4: 1997-1998, CP5: 1999-2006] through cumulative incidence curves and Cox proportional hazards models, allowing for late entry, that included the calendar period as the time-dependent covariate and adjusting for gender and mother's transmission category. The median follow-up was 11.8 years [interquartile range (IQR), 6.3-15.9]. Median CD4+ T cell percentage increased up to 26.5 in CP5 (IQR, 19.5-36.7) while the viral load decreased (median log(10) copies/ml in CP5, 3.66; IQR, 3.07-4.22). Multivariate analysis showed significant reduction in the risk of death since 1997 onward [CP4: adjusted hazard ratios (AHR), 0.29; 95% confidence interval (CI), 0.12-0.69; CP5: AHR, 0.06; 95% CI, 0.03-0.15]. Reduction in progression to AIDS reached borderline significance in CP4 (AHR, 0.49; 95% CI, 0.23-1.05) and was more marked in the last period (CP5: AHR, 0.30; 95% CI, 0.16-0.59). The reductions in the incidence of AIDS and death observed since 1996 were largely attributable to HAART.

Spatial pattern of HIV-1 mother-to-child-transmission in Madrid (Spain) from 1980 till now: demographic and socioeconomic factors.

OBJECTIVE: To evaluate any possible association between indicators of social inequalities and the geographical distribution of HIV-1 mother-to-child transmission (MTCT) cases in Madrid. METHODS: We carried out an observational survey of 224 HIV-1 vertically infected children born in 1980-2006 living in Madrid. We elaborated maps representing the prevalence of HIV-1 MTCT cases. We assessed the association between indicators of social inequalities and the spatial distribution of MTCT cases. Poisson univariate and multivariate analysis of risk factors for MTCT were performed. RESULTS: We identified core areas of transmission mainly in southern Madrid until 2006. The prevalence of MTCT cases was significantly correlated to the percentage of immigrants, illiterates, unemployed women and the income in 1996 and 2000/2001. The risk of MTCT increased in the periods up to 1996 compared with the calendar period 1980-1989, whereas the risk decreased in 1999-2006 [relative risk, 0.08; 95% confidence interval (CI), 0.03-0.18; P < 0.001]. The risk was especially high in the districts of Usera (absolute relative risk, 11.4; 95% CI, 2.6-49.5; P = 0.001), Puente de Vallecas (absolute relative risk, 14.0; 95% CI, 3.4-57.9; P < 0.001) and San Blas (absolute relative risk, 12.5; 95% CI, 2.9-53.6; P = 0.001). The percentage of illiterates was the indicator that explained the risk of MTCT (absolute relative risk, 1.07; 95% CI, 1.05-1.10; P = 0.001). CONCLUSION: We observed a geographic heterogeneity of the HIV-1 vertical transmission with the highest prevalence in disadvantaged districts. What is described in the present review is the HIV-1 vertical transmission within a social context; this approach could be relevant in analysing the pattern of HIV-1 transmission in other Western cities or highlighting the distribution of other infectious diseases.

NK cell increase in neonates from the preterm to the full-term period of gestation.

BACKGROUND: Several studies have reported differences in lymphocyte phenotype in preterm and full-term neonates as compared to children and adults. However, a detailed description of the immunologic cell populations of neonates corresponding to the gestational age is needed. This will be helpful for clinical practice to find the best way to prevent neonatal infections or strengthen the immune system of newborns with some kind of immunodeficiency. OBJECTIVE: To study maturation of the immune system throughout gestation, describing the variations of the lymphocyte populations in function of the gestational week when born. METHODS: We performed a descriptive study in 134 healthy newborns (gestation age 25-42 weeks), quantifying the relative and absolute counts of cell populations in umbilical cord blood obtained during delivery, by a four-color flow cytometry single platform. RESULTS: We first compared the very-preterm (25-30 weeks), preterm (31-36 weeks) and full-term (37-42 weeks) neonates. We found higher absolute counts of all cell populations in the full-term group and lower absolute and relative values of NK cells in the very-preterm group. After that, we analyzed the lymphocyte populations week to week (from week 31 to 41) and found the lowest values of T cells (CD4+ and CD8+) for week 36. However, lower percentages of CD4+ T cells and higher percentages of NK cells were observed in week 38 and 41. CONCLUSION: We found an increase in cord blood NK cells with gestational age, both in terms of absolute counts and of percentage values. Moreover, the %NK cells showed a pattern opposite to %CD4+ T cells along the studied period.

[Recommendations of the CEVIHP/SEIP/AEP/PNS on antiretroviral treatment in HIV-infected children and teenagers]. / Recomendaciones CEVIHP/SEIP/AEP/PNS respecto al tratamiento antirretroviral en niños y adolescentes infectados por el VIH.

OBJECTIVE: To update antiretroviral recommendations in antiretroviral therapy (ART) in HIV-infected children and adolescents. METHODS: Theses guidelines have been formulated by a panel of members of the Plan Nacional sobre el SIDA (PNS) and the Asociacion Espanola de Pediatria (AEP) by reviewing the current available evidence of efficacy, safety, and pharmacokinetics in pediatric studies. Three levels of evidence have been defined according to the source of data: Level A: randomized and controlled studies; Level B: Cohort and case-control studies; Level C: Descriptive studies and experts' opinion. RESULTS: When to start ART should be made on an individual basis, discussed with the family, considering the risk of progression according to age, CD4 and viral load, the ART-related complications and adherence. The ART goal is to reach a maximum and durable viral suppression. This is not always possible, even with clinical and immunologic improvement. The difficulties of permanent adherence and side-effects are resulting in a more conservative trend to initiate ART, and to less toxic and simpler strategies. Currently, combinations of at least three drugs are of first choice both in acute and chronic infection. They must include 2 NA 1 1 NN or 2 NA 1 1 PI. ART is recommended in all symptomatic patients and, with few exceptions, in all infants in the first year of life. Older asymptomatic children should start ART according to CD4 count, especially CD4 percentage, that vary with age. Despite potent salvage therapies, it is common not to reach viral undetectability. Therapeutical options when ART fails are scarce due to cross-resistance. The cause of failure must be identified. Occasionally, there exists clinical and/or immunological progression, and a change of therapy with at least two new drugs still active for the patient, is warranted with the aim of increasing the CD4 count to a lower level of risk. Toxicity and adherence must be regularly monitored. Some aspects about post exposure prophylaxis and coinfection with HCV or HBV are discussed. CONCLUSIONS: A higher level of evidence with regard to ART effectiveness and toxicity in pediatrics is currently available, leading to a more conservative and individualized approach. Clinical symptoms and CD4 count are the main determinants to start and change ART.

Ataxia telangiectasia / Ataxia-telangiectasia

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