Salvador Resino

Host adaptive immunity deficiency in severe pandemic influenza

IntroductionPandemic A/H1N1/2009 influenza causes severe lower respiratory complications in rare cases. The association between host immune responses and clinical outcome in severe cases is unknown.MethodsWe utilized gene expression, cytokine profiles and generation of antibody responses following hospitalization in 19 critically ill patients with primary pandemic A/H1N1/2009 influenza pneumonia for identifying host immune responses associated with clinical outcome. Ingenuity pathway analysis 8.5 (IPA) (Ingenuity Systems, Redwood City, CA) was used to select, annotate and visualize genes by function and pathway (gene ontology). IPA analysis identified those canonical pathways differentially expressed (P < 0.05) between comparison groups. Hierarchical clustering of those genes differentially expressed between groups by IPA analysis was performed using BRB-Array Tools v.3.8.1.ResultsThe majority of patients were characterized by the presence of comorbidities and the absence of immunosuppressive conditions. pH1N1 specific antibody production was observed around day 9 from disease onset and defined an early period of innate immune response and a late period of adaptive immune response to the virus. The most severe patients (n = 12) showed persistence of viral secretion. Seven of the most severe patients died. During the late phase, the most severe patient group had impaired expression of a number of genes participating in adaptive immune responses when compared to less severe patients. These genes were involved in antigen presentation, B-cell development, T-helper cell differentiation, CD28, granzyme B signaling, apoptosis and protein ubiquitination. Patients with the poorest outcomes were characterized by proinflammatory hypercytokinemia, along with elevated levels of immunosuppressory cytokines (interleukin (IL)-10 and IL-1ra) in serum.ConclusionsOur findings suggest an impaired development of adaptive immunity in the most severe cases of pandemic influenza, leading to an unremitting cycle of viral replication and innate cytokine-chemokine release. Interruption of this deleterious cycle may improve disease outcome.

Meta-analysis: implications of interleukin-28B polymorphisms in spontaneous and treatment-related clearance for patients with hepatitis C.

BackgroundSince 2009, several studies have identified single-nucleotide polymorphisms (SNPs) near the gene encoding for interleukin (IL)-28 (IL28B) that are strongly associated with spontaneous and treatment-induced hepatitis C virus (HCV) clearance. Because this large amount of data includes some inconsistencies, we consider assessment of the global estimate for each SNP to be essential.MethodsRelevant studies assessing IL28B polymorphisms associated with sustained virologic response (SVR) and spontaneous clearance (SC) were identified from a literature search of PubMed up to 9 July, 2012. Studies were eligible studies if they included patients infected with HCV or HCV/HIV, or assessed any SNP located within or near the IL28B gene, SVR data available under standard treatment, and/or SC data in patients with acute HCV infection. Pooled odds ratios were estimated by fixed or random effects models when appropriate. Variables such as HCV genotype, ethnicity, and type of co-infection were studied.ResultsOf 282 screened studies, 67 were selected for SVR and 10 for SC. In total, 20,163 patients were studied for SVR and 3,554 for SC. For SVR, we found that all SNPs showed strong associations in patients with HCV genotypes 1 and 4, whereas the pooled ORs were almost three times lower for genotypes 2 and 3 (rs12979860 and rs8099917). Regarding ethnicity, the SNP most associated with SVR was rs12979860 in white patients, whereas in East Asians it seemed to be rs8099917. The most studied SNP (rs12979860) showed similar results for patients co-infected with HCV/HIV, as for those infected with HCV only. Finally, rs12979860 and rs8099917 both appeared to be associated with SC.ConclusionsIL28B polymorphisms influence both the outcome of interferon treatment and the natural clearance of HCV. However we did not identify a universal predictor SNP, as the best genetic markers differed depending on patient ethnicity, genotype, and type of infection. Nevertheless, our results may be useful for more precise treatment decision-making.

Long-term effects of highly active antiretroviral therapy in pretreated, vertically HIV type 1-infected children : 6 years of follow-up

BACKGROUND Several studies of children with human immunodeficiency virus (HIV) type 1 infection have demonstrated sustained increases in CD4+ cell count, even when virological failure has occurred after receipt of highly active antiretroviral therapy (HAART), but these studies were of limited duration. Moreover, the CD4+ cell count threshold at which antiretroviral treatment should be initiated is still unsettled. The aim of this study was to define the long-term impact of HAART on CD4+ cell percentage and viral load according to CD4+ cell percentages before HAART was initiated. METHODS We conducted a retrospective study of 113 pretreated HIV-1-infected children stratified by pre-HAART CD4+ cell percentage (<5%, 5%-15%, 15%-25%, and >25%). The inclusion criteria were as follows: initiating HAART with a protease inhibitor, having 6 years of follow-up after starting HAART, having a CD4+ cell count or viral load recorded before initiation of HAART, and having received mono- or dual-nucleoside therapy before starting HAART. RESULTS During the first 2 years of HAART, HIV-1-infected children experienced a significant increase in CD4+ cell percentage and a decrease in viral load (P<.05). During their last 4 years of receiving HAART, we found a significant decrease in viral load but not an increase in CD4+ cell percentage, because the CD4+ cell percentage reached a plateau after the second year of HAART. Moreover, children with CD4+ cell percentages of <5% at baseline did not achieve CD4+ cell percentages of >25% after 6 years of HAART. Children with CD4+ cell percentages of 5%-25% at baseline had a strong negative association with achieving CD4+ cell percentages of >30% for at least 6 and 12 months but not with achieving CD4+ cell percentages of >30% for at least 24 months. CONCLUSIONS Long-term HAART allowed for restoration of CD4+ cell counts and control of viral loads in HIV-1-infected children. However, initiating HAART after severe immunosuppression has occurred is detrimental for the restoration of the CD4+ cell count.

Clinical Outcomes Improve with Highly Active Antiretroviral Therapy in Vertically HIV Type-1–Infected Children

Background. Use of antiretroviral therapy has resulted in a decrease in morbidity and mortality rates in human immunodeficiency virus type 1 (HIV-1)-infected children.Methods. We performed a retrospective study involving 427 children to determine the effectiveness of different antiretroviral therapy protocols on clinical outcome. The follow-up period was divided into 5 calendar periods (CPs): CP1 (1980-1989), before antiretroviral therapy was administered; CP2 (1990-1993), when monotherapy was administered; CP3 (1994-1996), when combined therapy was administered; CP4 (1997-1998), when </=50% of children were receiving highly active antiretroviral therapy (HAART); and CP5 (1999-2003), when >/=60% of children were receiving HAART.Results. Children experienced a progressive increase in the CD4(+) cell count and decrease in the viral load from 1997 onwards. A lower number of AIDS cases and deaths occurred during CP5 than during the other CPs (P<.01), with a relative risk of an absence of AIDS of >20 and a relative risk of survival of >30. The AIDS rate was >50% in CP1; we observed a very strong decrease to 14% in CP2, to 16% in CP3, to 7% in CP4, and to 2% in CP5. The mortality rates in CP2 and CP3 were >6% and thereafter decreased to 0.5% in CP5. The relative risks for no hospital admission in CP4 and CP5 were >3.5. The total rates of hospital admission in CP1, CP2, and CP3 were >30%; we observed a decrease in CP4 and CP5. The duration of hospitalization decreased during the follow-up period, and it was higher in CP1 (~30 days) than in the other periods.Conclusions. We observed that HAART produces a decrease in adverse clinical outcomes (i.e., hospital admission, AIDS, and death) in children with vertical HIV-1 infection in Madrid, Spain.

Predictive Markers of Clinical Outcome in Vertically HIV-1-Infected Infants. A Prospective Longitudinal Study

We have investigated the relationship between disease progression and several immunologic and virologic markers of HIV infection. Plasma samples from infants born to HIV-1–infected mothers were collected at birth and at 1, 2, 4, 6, 9, 12, 15, and 18 mo of age and subsequently were assayed every 6 mo for viral load, viral phenotype, and lymphocyte populations. A cutoff level of 25% indicative of a preserved immunologic status, both of CD4+ and CD8+ blood T cells, was associated with significant differences in disease progression (p = 0.04 and 0.02, respectively). Infants with median CD4+ T cells <25% had a relative risk of progression to AIDS 3.35-fold higher than those with CD4+ above this level (p = 0.05). The relative risk of progression to AIDS for infants with median CD8+ <25% was 4.95-fold higher than for those with CD8+ percent above this threshold (p = 0.03). Similarly, a cutoff level of viral load of 5.5 log10 copies/mL was indicative of a worse prognosis. Infants with median viral load >5.5 log10 copies/mL had a relative risk of progression to AIDS 23.72-fold higher (p = 0.0001) than those with median viral load below this threshold. Interestingly, changes from a slow replication and low titer to a rapid replication and high titer of virus and from nonsyncytium-inducing to syncytium-inducing viral phenotype were indicative of progression to AIDS. Our results indicate that biologic phenotype of viral isolates and CD8+ T-lymphocyte percentages in peripheral blood as well as viral load and CD4+ T-lymphocyte percentages could predict rapid progression to advanced HIV-1 disease in HIV-1–infected infants.

Modeling the Probability of Sustained Virological Response to Therapy with Pegylated Interferon plus Ribavirin in Patients Coinfected with Hepatitis C Virus and HIV

BACKGROUND A single-nucleotide polymorphism (SNP) near the IL28B gene (rs12979860) strongly predicts sustained virological response to pegylated interferon plus ribavirin (pegIFN-RBV) treatment for chronic hepatitis C virus (HCV) infection. Given that therapy is poorly tolerated and rates of response are lower in patients coinfected with HCV and human immunodeficiency virus (HIV), the recognition of predictors of response is a high priority in this population. METHODS A baseline noninvasive index was derived on the basis of the probability of achieving sustained virological response in a group of 159 HIV-HCV-coinfected patients treated at one clinic in Spain. The index was then validated using data from a separate cohort of 86 coinfected individuals. Only individuals who had completed a course of pegIFN-RBV therapy and had validated outcomes were considered. RESULTS The final score included 4 variables: 2 host-related variables (IL28B SNP rs12979860 and liver stiffness) and 2 HCV-related variables (genotype and viral load). The area under the receiver operating characteristic curve was 0.89 in the derivation group and 0.85 in the validation group. CONCLUSIONS The probability of achieving sustained virological response with pegIFN-RBV therapy in HIV-HCV-coinfected patients can be reliably estimated prior to initiation of therapy using an index that includes 4 noninvasive parameters.

Premature immunosenescence in HIV-infected patients on highly active antiretroviral therapy with low-level CD4 T cell repopulation

OBJECTIVES To analyse the role of thymic function and its association with cellular immunosenescence markers in patients with low-level CD4 T cell repopulation, despite complete HIV RNA replication control on highly active antiretroviral therapy (HAART). METHODS Cellular immunosenescence markers comparing patients with CD4 T cell counts <or=250 cells/mm(3) for >or=48 weeks (n = 11) and patients with a CD4 T cell count >or=500 cells/mm(3) (n = 11) were investigated. Both groups were also compared with 11 healthy volunteers of similar age. Naive CD4 T cell counts, beta- and delta-T cell rearrangement excision circles, recent thymic emigrants, replicative senescence marker, cell activation, and rate of apoptosis were analysed. The Mann-Whitney U-test was used to compare parameters between both low-level and high-level CD4 T cell repopulation groups, and healthy volunteers. RESULTS Our results showed a lower thymic activity in patients with low-level CD4 T cell repopulation, leading to a decline in CD4 T cell production. On the other hand, a higher activation along with a higher replicative senescence of CD4 T cells contributed to a higher rate of apoptotic CD4 T cells in this group of patients. CONCLUSIONS We propose a model with several different related mechanisms involved in premature immune senescence in HIV-infected patients with low-level CD4 repopulation on HAART. The understanding of such different mechanisms could help find effective strategies to prevent immune decay.

CD38 Expression in CD8+ T Cells Predicts Virological Failure in HIV Type 1–Infected Children Receiving Antiretroviral Therapy

An observational study of children vertically infected with human immunodeficiency virus type 1 (HIV-1) was performed to determine the role of CD38 expression in CD8(+) T cells as prognostic marker of virological failure in children receiving HAART. We studied 42 children who were receiving antiretroviral therapy and who had an undetectable virus load (uVL), and we found a negative correlation between CD38 expression in CD8(+) T cells and the duration of uVL. We selected 17 HIV-1-infected children with CD38 values close to the baseline level (i.e., the first uVL achieved), and we distributed the children into 2 groups on the basis of median CD38 value in CD8(+) T cells. Children with CD38 values in CD8(+) T cells that were higher than the median had a higher incidence and relative risk of virological failure than did those with values lower than the median. In conclusion, we demonstrate for the first time that CD8(+)CD38(+) T cell count is a good prognostic marker of therapeutic failure in HIV-1-infected children.

HIV‐infected children with moderate/severe immune‐suppression: changes in the immune system after highly active antiretroviral therapy

The objective of this study was to monitor the changes in the immune system of HIV‐infected children with moderate or severe immunodeficiency after highly active antiretroviral therapy (HAART), comprising a follow‐up study in 14 HIV‐infected children on HAART at two time points separated approximately by 11·8 ± 0·4 (9·9; 15·4) months. HIV‐infected children had significantly lower TREC levels than the control group, but 1 year after HAART the levels increased significantly (P < 0·05). In contrast, viral load (VL) did not change significantly. A positive correlation between T cell receptor excision circle (TREC) levels and both CD4+ T cell absolute counts (r = 0·558; P = 0·05) and percentages (r = 0·625; P = 0·030) was found. During follow‐up on HAART, the percentages and absolute counts of naive CD4+ and CD8+ T cell subsets were increased significantly (P < 0·05). CD4+ CD45RAhi+ CD62L+, CD4+ CD45RA+ and CD4+ CD38+ percentages, and the CD8+ CD45RAhi+ CD62L+ counts reached similar values to the control group. Also, CD8+ CD45RO+ CD38+ and CD8+ CD45RO+ percentages, and CD8+ CD45RO+ CD38+ absolute counts (P < 0·05) decreased with respect to the baseline. Lymphoproliferative responses to pokeweed mitogen (PWM) before HAART were lower in HIV‐infected children than the control group, but they recovered to normal levels after a year on HAART. Tumour necrosis factor (TNF)‐α and interferon (IFN)‐γ production by PHA‐activated peripheral blood mononuclear cells (PBMC) was lower before HAART (P < 0·001), but reached similar levels to the control group 1 year after HAART. In HIV‐infected children IgG, IgG1 and IgG3 plasma levels decreased significantly after HAART. The immune system reconstitution induced by HAART in HIV‐infected children seems to be the consequence of decreased immune system activation and naive T cell reconstitution, mainly of thymic origin.

Relationship of vitamin D status with advanced liver fibrosis and response to hepatitis C virus therapy: A meta‐analysis

There is growing evidence that vitamin D is related to chronic hepatitis C (CHC) pathogenicity. We analyzed the relationship of vitamin D status with advanced liver fibrosis (ALF) in CHC treatment‐naïve patients and sustained virologic response (SVR) in CHC patients on pegylated interferon alpha plus ribavirin (pegIFNα/ribavirin) therapy. We performed a meta‐analysis of all eligible studies published to date (April, 2014) in PubMed, SCOPUS, LILACS, and the Cochrane Library, assessing plasma/serum vitamin D levels related to ALF and/or SVR. Pooled odds ratios (ORs) were estimated by either fixed or random effects models. Fourteen studies were selected from the literature search, seven for ALF (1,083 patients) and 11 for SVR (2,672 patients). For liver fibrosis, low vitamin D status was related to a diagnosis of ALF, with the cutoffs of 10 ng/mL (OR = 2.37, 95% confidence interval [CI] = 1.20, 4.72) and 30 ng/mL (OR = 2.22, 95% CI = 1.24, 3.97) being significant, and a near‐significance for 20 ng/mL (OR = 1.44, 95% CI = 0.99, 2.12). Regarding SVR, a significant heterogeneity among studies was found (P < 0.001), and we only found a significant association with SVR for a vitamin D cutoff of 20 ng/mL (OR = 0.53, 95% CI = 0.31, 0.91). When meta‐analysis was performed excluding the outliers, significant pooled ORs were found for all patients (10 ng/mL [OR = 0.48, 95% CI = 0.34, 0.67] and 20 ng/mL [OR = 0.58, 95% CI = 0.45, 0.76]) and GT1/4 patients (10 ng/mL [OR = 0.53, 95% CI = 0.34, 0.81] and 20 ng/mL [OR = 0.54, 95% CI = 0.39, 0.74]). Conclusion: Low vitamin D status in CHC patients is associated with a higher likelihood of having ALF and lower odds of achieving SVR following pegIFNα/ribavirin therapy. (Hepatology 2014;60:1541–1550)