Luca Meroni

Comparative analysis of T-cell turnover and homeostatic parameters in HIV-infected patients with discordant immune-virological responses to HAART

Objective:Inadequate CD4 cell count recovery despite full HIV RNA control occurs in 30% of HAART-treated HIV-infected patients. A better understanding of the relationship between T-cell dynamics and the HIV intracellular reservoir in HIV-infected patients failing to recover CD4 cell count following long-term HAART, is required. Methods:In a cross-sectional study T-cell turnover and homeostatic parameters featuring discordant responses were investigated in 27 immunologic non-responders (INR; CD4 count, ≤ 200 cells/μl; HIV RNA, ≤ 50 copies/ml), 15 virological non-responders (VNR; CD4 count, ≥ 350 cells/μl; HIV RNA, ≥ 10 000) and 22 full responders (FR; CD4 count, ≥ 500 cells/μl; HIV RNA, ≤ 50 copies/ml). Results:INR displayed significantly higher activated CD38CD8 than FR (P < 0.05) and was comparable to VNR (P > 0.05). As compared with VNR and FR, INR displayed the highest level of proliferating Ki67CD4 and apoptotic CD4 cells (P < 0.05). VNR presented lower proliferation and apoptosis than FR and INR. INR displayed the lowest levels of naive T cells (P < 0.05) and a predominant memory pattern. Despite the memory/activated/apoptotic phenotype, INR showed a statistically non-significant reduction in T-cell receptor excision circles (TREC) compared to FR (P > 0.05), and substantially heightened interleukin (IL)-7 (P < 0.05), while VNR showed higher naive T-cell counts and TREC. Moreover, the reservoir of infected CD4 cells was increased in INR, with a trend toward highest intracellular HIV DNA within total, naive and memory CD4 cells. Conclusions:The lack of CD4 cell count recovery in INR seems to reflect a highly activated apoptotic T-cell compartment, with elevated IL-7 and thymic impairment. High levels of intracellular HIV-DNA in INR could be strictly involved in the lack of T-cell reconstitution. Immune correlates of an ultimate direction of the response to HAART, could be exploited in clinical practice for the most effective management of discordant patients, to amend immune imbalances and to improve clinical outcome.

Antiretroviral treatment and age-related comorbidities in a cohort of older HIV-infected patients

The availability of several therapeutic regimens has transformed HIV infection from a life‐threatening disease into a chronic condition. Older patients (>50 years old) with HIV infection constitute a new treatment challenge in terms of the cumulative effects of ageing and antiretroviral therapy (ART).

Evidence for type 2 cytokine production and lymphocyte activation in the early phases of HIV-1 infection

ObjectiveTo analyse changes in cytokine production in vitro and T-Iymphocyte immunophenotype in the early phases of HIV-1 infection. Design and methodsMitogen-stimulated in vitro production of interferon (IFN)-γ, interleukin (IL)-2 (type 1 cytokines), IL-4, and IL-10 (type 2 cytokines) and surface expression of activation and non-activation markers were evaluated in 11 individuals HIV-infected for >3 but <12 months (seroconverters). The data were compared to those obtained in 33 asymptomatic HIV-positive individuals infected >3 years previously and who were stratified according to CD4+ lymphocyte count (group 1: >500 × 106/l, group 2: <500 × 106/l CD4 cells) and in 12 HIV-seronegative healthy controls. ResultsWe observed that the early phase of HIV infection is characterized by (1) reduced mitogen-stimulated IL-2 and IFN-γ production, (2) increased mitogen-stimulated IL-4 and IL-10 production, (3) a relative decrease in CD4+ and CD4+CD7− as well as an increase in CD4+CD7-CD57+ Iymphocytes, and (4) a relative increase in CD8+, CD8+CD38+ and CD8+CD57+ T lymphocytes. In addition, during a 6-month follow-up of six seroconverters we observed a dynamic pattern of changes of these parameters in most individuals, with a resulting profile similar to that observed in group 1 HIV-positive patients. ConclusionThe early phase of HIV infection is immunologically characterized by type 2 cytokine secretion and alterations in the expression of phenotypic markers, and closely resembles the more advanced phases of HIV infection. These immunologic alterations are temporally limited by the successive return to a more normal profile. Thus, HIV infection is an immunological complex dynamic process even in its earliest phases.

Post-kala-azar dermal leishmaniasis as an immune reconstitution inflammatory syndrome in a patient with acquired immune deficiency syndrome

Post‐kala‐azar dermal leishmaniasis (PKDL) is a complication of visceral leishmaniasis (VL) observed mainly in Sudan and India where it follows treated VL in 50% and 10% of cases, respectively. We report a 46‐year‐old patient with acquired immune deficiency syndrome who, 7 months after diagnosis of VL, developed PKDL and uveal leishmaniasis following HAART‐induced immune recovery. In southern Europe PKDL seems to be an emerging clinical presentation among human immunodeficiency virus (HIV)‐infected patients experiencing HAART‐induced immune recovery after a previous diagnosis of VL. The best treatment among HIV‐infected patients remains to be determined.

Human parvovirus 4 in the bone marrow of Italian patients with AIDS.

Human parvovirus 4 (PARV4) is a recently discovered member of the Parvoviridae. We investigated the presence of this virus in bone-marrow aspirates of 35 Italian patients with AIDS. Viral DNA was detected by polymerase chain reaction in over 40% of patients (16/35). The infection was most prevalent in injection drug users (IDU; 12/18; 66.7%) as opposed to non-IDU (4/17; 23.5%). PARV4 infection is widespread in Italian patients with AIDS.

Detection of Hepatitis C Virus RNA in CD19 Peripheral Blood Mononuclear Cells of Chronically Infected Patients

The presence of HCV RNA in peripheral blood mononuclear cells (PBMC) has been reported. To identify the cell populations carrying HCV RNA, the presence and amount of HCV RNA was investigated by limiting dilution nested reverse transcriptase-polymerase chain reaction (PCR) in PBMC subpopulations fractionated by automated cell sorting. Fifteen chronically HCV-infected patients were included in the study, 4 of whom also had mixed cryoglobulinemia. HCV RNA was present in the CD19 cells of all 15 patients, but only 5 (35.7%) of 14 and 5 (41.6%) of 12 showed HCV RNA in CD3 and CD14 cells, respectively (P < .001 by Fishers test for each comparison). The median titer of HCV RNA was 1 PCR unit/380 CD19 cells, compared with median of 1 PCR unit/6600 PBMC as a whole. Titration was difficult in the CD3 and CD14 cells because of the frequent negativity of the first diluted sample. This study suggests that HCV RNA is selectively concentrated in B cells.

Does fluvastatin favour HCV replication in vivo? A pilot study on HIV-HCV coinfected patients.

Summary.  Fluvastatin showed anti‐hepatitis C virus (HCV) activity in vitro, through the inhibition of geranylgeranylation of cellular proteins, and a synergistic effect with interferon (IFN)‐α. Nevertheless statins up‐regulate low‐density lipoprotein (LDL) receptor, required for HCV cell entry, and the closely related scavenger receptors SRBI and CD36; moreover they reduce class II major histocompatibility complex expression on antigen presenting cell, modulating T‐cell activation. In vivo LDL levels have been identified as prognostic indicator of sustained viral response to IFN in patients with HCV infection, suggesting that lipid‐lowering agents might conversely favour HCV entry into the hepatocytes and translate into higher viral replication. We evaluated the effect of fluvastatin on HCV‐RNA levels, CD36 expression and T‐cell homeostasis in HCV‐RNA positive patients. HCV‐RNA was measured at baseline and after 4 weeks in 42 HCV/HIV‐1 co‐infected patients, randomized to receive either fluvastatin 80 mg qd or no treatment. CD36 expression and markers of T‐cell activation were evaluated by means of flow cytometry. Plasma interleukin (IL)‐10, IFN‐γ and IL‐7 were measured by ELISA. Serum cholesterol and LDL decreased significantly in the treatment group (P = 0.0001 and 0.01, respectively). Surprisingly a significant increase of HCV‐RNA levels was seen after 4 weeks of fluvastatin (P = 0.03). The percentages of naive/activated/apoptotic cells and CD36 expression remained unchanged. Fluvastatin did not inhibit HCV‐RNA replication in vivo; conversely we observed a significant increase of HCV‐RNA levels. CD36 expression on monocytes were not up‐regulated by statins as previously reported in vitro. The correlation between HCV infectivity, oxidized‐LDL receptor and statins in HCV infection need further evaluation.

Aspergillus meningitis: a rare clinical manifestation of central nervous system aspergillosis. Case report and review of 92 cases.

Summary Objectives To describe the pathogenesis, clinical presentation, cerebrospinal fluid findings and outcome of Aspergillus meningitis, meningoencephalitis and arachnoiditis. Methods A case of Aspergillus meningitis is described. A comprehensive review of the English-language literature was conducted to identify all reported cases of Aspergillus meningitis described between January 1973 and December 2011. Results Ninety-three cases (including the one described herein) of Aspergillus meningitis were identified. Fifty-two (55.9%) were in individuals without any predisposing factor or known causes of immunosuppression. Acute and chronic meningitis was diagnosed in 65.6% of patients and meningoencephalitis in 24.7% of them with the remaining presenting with spinal arachnoiditis and ventriculitis. Cerebrospinal fluid cultures for Aspergillus spp. were positive in about 31% of cases and the galactomannan antigen test in 87%. Diagnosis during life was achieved in 52 patients (55.9%) with a case fatality rate of 50%. The overall case fatality rate was 72.1%. Conclusions Aspergillus meningitis may occur in both immunocompetent and immunocompromised patients and run an acute or chronic course. The findings of this systematic review extend the information on this life-threatening infection and could assist physicians in achieving an improved outcome.

Interleukin-2 immunotherapy exerts a differential effect on CD4 and CD8 T cell dynamics.

Background: Emerging evidence indicates that CD4 and CD8 T cell recovery is differentially regulated during HIV infection. The hallmark of interleukin-2 (IL-2)-induced immune reconstitution is the selective outgrowth of CD4 through undefined mechanisms. Objective: To delineate the effect of IL-2 on T cell homeostasis by analysing the differential impact of IL-2 immunotherapy on CD4 and CD8 dynamics. Design: A randomized trial of 15 HIV-positive patients, eight receiving IL-2 immunotherapy with highly active antiretroviral therapy (HAART) and seven with HAART alone. Patients were followed for a 48-week period following three IL-2 cycles (overall, 10 weeks in duration). Methods: CD4 and CD8 count, naive and memory immunophenotype, proliferation by Ki67, and CD8+CD38+ activated pattern were measured longitudinally by flow cytometry. Thymic output contribution to both CD4 and CD8 was evaluated by measurement of T cell receptor excision circles (TREC). Wilcoxon test was used to compare results. Results: Compared with changes seen with HAART alone, IL-2 induced a more significant rise in CD4 than CD8 T cell count (P < 0.01), associated with a significant increase in Ki67-proliferating CD4 (P < 0.05), whereas no changes were seen in CD8+Ki67+ (P > 0.05). Furthermore, IL-2 administration was associated with CD4 TREC increase, whereas CD8 TREC remained stable (P > 0.05). Modifications in CD4 and CD8 T cells seen in patients taking only HAART were not associated with changes in CD4 and CD8 TREC. Conclusions: By showing a differential impact on CD4 and CD8 homeostasis, the study suggests that IL-2-associated immune reconstitution results from protean interactions between T cell compartments; this has significant implications for the correct planning of immunotherapeutic strategies.

Skewed T-cell maturation and function in HIV-infected patients failing CD4+ recovery upon long-term virologically suppressive HAART.

Objective:Analysis of functionally defined T-cell differentiation in HIV-infected patients with low CD4+ on virologically suppressive HAART is crucial to design clinically efficacious treatments. Methods:We cross-sectionally investigated the maturation (CD45RA/CCR7, CD7) and function [antigen-specific enzyme-linked immunosorbent spot assay (ELISPOT), interleukin-2 (IL-2)/interferon-γ-producing cells] of CD4+ and CD8+ T cells in 34 HIV-infected immunological nonresponders (INRs): CD4+ cell count less than or equal to 200 cells/μl, HIV-RNA 50 copies/ml or less, as compared to 20 full responders (CD4+ > 500 cells/μl, HIV-RNA < 50 copies/ml). Results:We describe skewed T-cell maturation in INRs with outgrowth of effector memory CD45RA−CCR7− CD4+/CD8+ and Th2-committed CD7−CD4+, and reduced unprimed-naive T cells (P = 0.001). Functionally, INRs display reduced Gag-specific ELISPOT (P = 0.04) and IL-2-secreting CD8+ (P = 0.08) while showing CMV-specific responses comparable to full responders. Conclusion:CD4 lymphopenia on HAART results in skewed, senescent T-cell maturation profile, inefficient T-helper function and poor HIV-specific CD8+ response. This delineates a functional/phenotypic T-cell pattern that correlates to unfavourable clinical outcome.