Meritxell Nomdedeu

Long-term CD4+ T-cell response to highly active antiretroviral therapy according to baseline CD4+ T-cell count.

Current treatment guidelines for HIV infection recommend a relatively late initiation of highly active antiretroviral therapy (HAART). Nevertheless, there is still a concern that immune recovery may not be as complete once CD4+ T cells have decreased below a certain threshold. This study addressed the long-term response of CD4+ T-cell counts in patients on HAART and analyzed the influence of baseline CD4+ T-cell counts, baseline viral load, and age. An observational analysis of evolution of CD4+ T cells in 861 antiretroviral therapy–naive chronic HIV-1–infected patients who started treatment consisting of at least 3 drugs in or after 1996 was performed. Patients were classified in 4 groups according to baseline CD4+ T cells: <200 cells/mm3, 200–349 cells/mm3, 350–499 cells/mm3, and ≥500 cells/mm3. The main outcome measures were proportion of patients with CD4+ T cells <200/mm3 and >500/mm3 at last determination and rate of CD4+ T-cell recovery. Patients were followed-up for a median of 173 weeks (interquartile range [IQR], 100–234). There were no differences in follow-up between the 4 groups. CD4+ T cells increased in the whole cohort from a median of 214 cells/mm3 (IQR, 90–355) to 499 cells/mm3 (IQR, 312–733) (P < 0.001). Compared with the group with a baseline CD4+ T-cell count of ≥500/mm3, the relative risk of having a last determination of CD4+ T-cell counts >200 cells/mm3 was 0.79 (95% CI, 0.75–0.83), 0.92 (95% CI, 0.89–0.96) and 1 for baseline CD4+ T cells <200 cells/mm3, 200–349 cells/mm3, and 350–499 cells/mm3, respectively. The relative risk of having a last determination of CD4+ T-cell counts >500 cells/mm3 was 0.32 (95% CI, 0.27–0.39, P < 0.001), 0.69 (95% CI, 0.60–0.79, P < 0.001), and 0.94 (95% CI, 0.83–1.06, P = 0.38) for baseline CD4+ T-cell counts <200 cells/mm3, 200–349 cells/mm3, and 350–499 cells/mm3, respectively, compared with a baseline CD4+ T-cell count of ≥500 cells/mm3. The increase in CD4+ T cells from baseline was statistically significant and was maintained for up to 4 years of follow-up. This increase seemed to slow down after approximately 3 years and reached a plateau after 4–5 years of follow-up even in patients who achieved and maintained viral suppression in plasma. Long-term immune recovery is possible regardless of baseline CD4+ T-cell count. However, patients who start therapy with a CD4+ T-cell count <200 cells/mm3 have poorer immunologic outcome as measured by the proportion of patients with CD4+ T cells <200/mm3 or >500/mm3 at last determination. It seems that the immune recovery slows down after approximately 3 years of HAART and reaches a plateau after 4–5 years of HAART.

Immunological profile of heterosexual highly HIV-exposed uninfected individuals: Predominant role of CD4 and CD8 T-cell activation

BACKGROUND Altered T cell subset distribution patterns in uninfected individual highly exposed to human immunodeficiency virus (HIV) have been explained either as a consequence of viral exposure or as a surrogate marker of low susceptibility to infection. METHODS Multiple genetic and immunological parameters were studied prospectively in 21 HIV-serodiscordant heterosexual couples. RESULTS We found changes of both CD4(+) and CD8(+) T cells in highly HIV-exposed, uninfected individuals, with a lower level of naive and CD28(+) T cells and higher levels of HLA-DR(+) T cells and CD4(+) T cells expressing CCR5 and memory CD4(+) T cells than in control subjects. The changes in memory and activated T cells observed in highly HIV-exposed, uninfected partners were directly correlated with plasma viral load (PVL) of the HIV-1-infected partners, whereas changes in naive and CD4(+) CD28(+) T cells observed in highly HIV-exposed uninfected partners were inversely correlated with PVL of the HIV-1-infected partners. We were only able to detect HIV-1-specific T-cell responses in a few highly HIV-exposed uninfected partners. CONCLUSIONS These data suggest that the peripheral immune cells of highly exposed, uninfected individuals responded according to the level of HIV exposure from the partner, even though evidence of specific HIV stimulation is rarely seen.

Response to lenalidomide in myelodysplastic syndromes with del(5q): influence of cytogenetics and mutations

Lenalidomide is an effective drug in low‐risk myelodysplastic syndromes (MDS) with isolated del(5q), although not all patients respond. Studies have suggested a role for TP53 mutations and karyotype complexity in disease progression and outcome. In order to assess the impact of complex karyotypes on treatment response and disease progression in 52 lenalidomide‐treated patients with del(5q) MDS, conventional G‐banding cytogenetics (CC), single nucleotide polymorphism array (SNP‐A), and genomic sequencing methods were used. SNP‐A analysis (with control sample, lymphocytes CD3+, in 30 cases) revealed 5q losses in all cases. Other recurrent abnormalities were infrequent and were not associated with lenalidomide responsiveness. Low karyotype complexity (by CC) and a high baseline platelet count (>280 × 109/l) were associated with the achievement of haematological response (P = 0·020, P = 0·013 respectively). Unmutated TP53 status showed a tendency for haematological response (P = 0·061). Complete cytogenetic response was not observed in any of the mutated TP53 cases. By multivariate analysis, the most important predictor for lenalidomide treatment failure was a platelet count <280 × 109/l (Odds Ratio = 6·17, P = 0·040). This study reveals the importance of a low baseline platelet count, karyotypic complexity and TP53 mutational status for response to lenalidomide treatment. It supports the molecular study of TP53 in MDS patients treated with lenalidomide.

Red blood cell alloimmunization in transfused patients with myelodysplastic syndrome or chronic myelomonocytic leukemia

BACKGROUND: Red blood cell (RBC) alloimmunization is a major problem in chronically transfused patients because of the risk of hemolytic reactions and limited availability of compatible blood. This study was aimed at determining the characteristics of RBC alloimmunization in transfusion‐dependent patients with myelodysplastic syndrome or chronic myelomonocytic leukemia (MDS/CMML).

Polymorphisms in the interleukin-4 receptor α chain gene influence susceptibility to HIV-1 infection and its progression to AIDS

Interleukin (IL) 4 is a key T helper-2 cytokine that downregulates and upregulates CCR5 and CXCR4, respectively, the main coreceptors for HIV. Our objective is to investigate whether single-nucleotide polymorphisms (SNPs) in the IL-4 receptor α chain gene (IL4RA) affect HIV infection and its progression to AIDS. The I50V SNP in exon 5 and the haplotypes of six SNPs in exon 12 (E375A, C406R, S411L, S478P, Q551R, and V554I) were studied by polymerase chain reaction and sequencing in 30 HIV+ long-term nonprogressors (LTNP), 36 HIV+ typical progressors (TP), 55 highly exposed but uninfected individuals (EU), 25 EU-sexuals (EU-Sex; mostly women) and 30 EU-hemophiliacs (EU-Hem; hepatitis C virus+), and 97 healthy controls (HC), all Caucasians and lacking CCR5Δ32 homozygosity. V50 homozygosity was increased in LTNP (44%) compared with the other groups [p=0.005; relative risk ratio=3.4, 95% confidence interval (CI)=1.12–10.6, p=0.03]. The most common (C) exon 12 haplotype, ECSSQV, predominated in all groups, but uncommon (U) haplotypes were increased in HIV+ individuals (n=64), especially in those (51 of 64) infected via parenteral exposure (35.3%) compared with HC (20.4%) and EU-Hem (18.4%) [p=0.01; odds ratio (OR)=2.14, 95% CI=1.25–3.67, p=0.01]. EU-Sex also had an increased frequency of U-haplotypes (34.8%) (OR=2.10, 95% CI=1.03–4.21, p=0.01) as well as an increased frequency of CU + UU genotypes (60.9%) compared with HC (38.2%) and EU-Hem (26.6%) (p=0.043). Distributions of genotypes fitted Hardy–Weinberg equilibrium. Data suggest that V50 homozygosity associates with slow progression and that exon 12 U-haplotypes might be associated with both susceptibility to infection via parenteral route and resistance to infection via sexual exposure. Further studies are required to confirm these findings.

Transfusion intensity, not the cumulative red blood cell transfusion burden, determines the prognosis of patients with myelodysplastic syndrome on chronic transfusion support†

Transfusion‐dependency is associated with poor prognosis in patients with MDS although the causal link for such association is disputed. This study tests thee hypotheses on the association between transfusion burden and prognosis in the MDS: (1) the cumulative transfusion burden is a confounder merely reflecting the time elapsed from diagnosis; (2) it is a surrogate for higher transfusion intensity, which would reflect a more severe disease; and (3) it is the total amount of transfused RBC units that influences on prognosis. We studied 191 transfusion‐dependent patients with MDS or chronic myelomonocytic leukemia. Transfusion intensity was calculated at the time of each transfusion as the yearly‐equivalent number of RBC units. The main outcome was acute leukemia‐free survival from first transfusion. Median transfusion burden was 30 (range: 4–330) RBC units and 112 patients received ≥25 units after a median of 9 months from first transfusion. In nested Cox models, having received ≥25 RBC units had a significant effect on survival (P < 0.001) that was not abrogated by including follow‐up ≥9 months as a time‐dependent covariate. Including transfusion intensity in the model had a significant effect on leukemia‐free survival (P < 0.001) and cancelled the prognostic value of having received ≥25 RBC units. In conclusion, transfusion intensity, instead of the cumulative transfusion burden, is the transfusion‐related variable really influencing on the prognosis of patients with transfusion‐dependent MDS. Am. J. Hematol. 86:245–250, 2011.

Immunological dysfunction in HIV-1-infected individuals caused by impairment of adenosine deaminase-induced costimulation of T-cell activation

The cell surface association between CD26 and adenosine deaminase (ADA) has a costimulatory function during T‐cell activation. Several studies have revealed correlations among CD4+ CD26+ T‐cell depletion, increased serum levels of ADA, and the evolution of human immunodeficiency virus (HIV) infection, implicating CD26 and ADA in HIV disease progression. In this context, we aimed to determine whether ADA costimulation could be altered during HIV infection. ADA costimulation was investigated in cells from HIV‐infected patients (n = 36) in terms of proliferation and cytokine secretion. An effect of ADA on T‐cell proliferation was found in HIV‐1‐infected patients and correlated positively with the CD4+ percentage and the nadir CD4 count and negatively with viral load, demonstrating that the response depends on the immunological status of the patient. The robust ADA‐induced increase in cytokine production [interferon (IFN)‐γ, interleukin (IL)‐6 and IL‐10] was markedly reduced in T cells from HIV‐1‐infected subjects. To eliminate some of the variables associated with immunological defects in HIV‐1‐infected patients, anti‐CD3 plus ADA assays with T cells from healthy volunteers were performed in the presence of recombinant glycoprotein 120 (gp120). It was found that gp120 was responsible for the impairment of the ADA–CD26 interaction and consequently of the ADA‐induced effect on both costimulation and cytokine production. The gp120‐mediated disruption of the CD26–ADA interaction is a novel mechanism that might explain, at least in part, the altered immunological features observed in HIV‐1‐infected patients and may have significant relevance in AIDS pathogenesis.

Reciprocal translocations in myelodysplastic syndromes and chronic myelomonocytic leukemias: Review of 5,654 patients with an evaluable karyotype

The infrequency of translocations in myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemias (CMML) makes their identification and reporting interesting for the recognition of the recurrent ones and the genes involved in these neoplasias. The aims of this study were to identify new translocations associated with MDS and CMML and to establish their frequency in a cohort of 8,016 patients from the Spanish Group of MDS database. The karyotype was evaluable in 5,654 (70%) patients. Among those, 2,014 (36%) had chromosomal abnormalities, including 213 (10%) translocations identified in 195 patients. The translocations were balanced in 183 (86%) cases and unbalanced in 30 (14%) cases. All chromosomes were found to be involved in translocations, with the single exception of the Y chromosome. The chromosomes most frequently involved were in decreasing frequency: 3, 1, 7, 2, 11, 5, 12, 6, and 17. Translocations were found in karyotypes as the unique chromosomal abnormality (33%), associated with another chromosomal abnormality (11%), as a part of a complex karyotype (17%), and as a part of a monosomal karyotype (38%). There were 155 translocations not previously described in MDS or CMML and nine of them appeared to be recurrent.

Phenotypic and functional characteristics of HIV-specific CD8 T cells and gag sequence variability after autologous dendritic cells based therapeutic vaccine.

A decrease in HIV-1 specific CD8 T-cell responses associated with a partial control of viral replication occurred in 12 HIV-1-infected patients during autologous dendritic cells vaccination. HIV CD8 T cells were detected in 6/10 patients during immunizations, increasing after HAART discontinuation in 3 of them. Tet+ CD8 cells mainly had an effector phenotype (CD45RA-/+ CCR7- and CD28- and Perf+/-) and maintained IFN-gamma release throughout follow-up. By contrast, patients with CD45RA-/+ CCR7+ Perf+ HIV-specific cells showed a decrease in peptide-specific IFN-gamma production during vaccinations while levels were recovered when off HAART. No major mutations in either Gag p24 and p17 immunodominant epitopes were observed that might have explained the impaired CD8+ T-cell responses. Taken together, heterogeneity in the maturation status of HIV-specific CD8 T cells may be partially involved in the drop of peptide-specific IFN-gamma production during immunizations.

High levels of global DNA methylation are an independent adverse prognostic factor in a series of 90 patients with de novo myelodysplastic syndrome

The prognostic impact of global DNA methylation and hydroxymethylation was assessed in 90 patients with de novo myelodysplastic syndrome (MDS). DNA was isolated from bone marrow samples obtained at diagnosis and global methylation and hydroxymethylation were determined by ELISA. Patients with a percentage of methylated DNA above 2.73% had a shorter overall survival than those with lower levels (P=0.018) and presented a negative trend in terms of leukemia-free survival (P=0.084), that was statistically significant after censoring 9 patients that received disease-modifying treatments both in univariate and multivariate analyses. Similarly, the low-risk MDS patients defined by the IPSS, WPSS and IPSS-R with 5-mC percentage in total DNA above 2.73% had a shorter overall survival (P=0.032; P=0.023; P=0.031). No cut-off value for the 5-hydroxymethylcytosine percentage with statistical significance for overall or leukemia-free survival was obtained. This study suggests that global DNA methylation predicts overall survival in myelodysplastic syndromes.