Claudin-1 gene variants and susceptibility to hepatitis C infection in HIV-1 infected intravenous drug users (an ANRS case-control study)

Hepatitis C virus (HCV) seroprevalence is highly diverse among human immunodeficiency virus-1 (HIV-1) infected patients, ranging between 10% of HIV-1 infected homo-bisexuel men, to >92% in patients infected with HIV-1 who acquired HIV-1 through intravenous drug use. Thus, being HCV-free while having acquired HIV-1 via intravenous drug use is a rare situation. Claudin-1 is a protein involved in intracellular tight-junctions and has been identified as a major cellular co-receptor for HCV infection. Our objective was to determine whether Claudin-1 gene (CLDN1) mutations might be involved in natural resistance to HCV infection. We conducted a case-control study. All recruited patients acquired HIV-1 infection via intravenous drug use route before 1995. The case study patients remained free from HCV infection (negative anti-HCV antibodies and HCV-RNA). The control study patients was co-infected with HCV (positive anti-HCV antibodies). Direct genomic sequencing of the CLDN1 gene coding region and adjacent intron/exons junctions was performed from peripheral blood mononuclear cells. A total of 138 Caucasian patients were enrolled. Twenty-two patients (cases) were free from HCV infection and 116 (controls) were co-infected with HCV. We found single nucleotide polymorphisms (SNPs) described previously with no significant differences in allele frequencies between cases and controls. In conclusion, despite being a major cellular co-receptor for HCV entry in vitro, we did not identify any specific substitution in CLDN1 gene coding region in our study patients highly exposed but resistant to HCV infection in vivo. Other cellular co-factors involved in HCV infection should be investigated in this highly-exposed intravenous drug users patients.

[Enhancing immune restoration in human immunodeficiency virus infection]

The primary objective of antiretroviral therapy has recently evolved from a virologic endpoint towards the achievement of normal CD4T cell count (greater than 500/mm(3)) to avoid progression to AIDS. This shift in the primary objective is supported by many clinical and epidemiological studies. Recent data have shown that HIV-infected adults with a CD4T cell count greater than 500cells/mm(3) on long-term combination antiretroviral therapy reach same mortality rates as the general population. However, less than 50% of patients receiving long-term suppressive antiretroviral combination reach such a CD4T cell level. New antiretroviral strategies to improve immune reconstitution, such as specific or non-specific immune-based therapy on one hand and the use of novel antiretroviral drugs from new classes on the other hand are currently under investigation. Here we review several current strategies that may improve immune reconstitution, keeping in mind that the best way to reach normal CD4T cell count is an early treatment initiation.

Breast enlargement in an HIV-infected man on combined antiretroviral therapy: what if it was carcinoma?

We describe a case of an HIV-infected man on effective combined antiretroviral therapy, presenting with bilateral gynaecomastia revealing breast carcinoma. Gynaecomastia was first considered to be related to efavirenz and/or didanosine. Although breast carcinoma is rare among HIV-infected men, it should be considered as a potential cause of breast enlargement.

Glomerular lesions in patients with sickle cell disease

Sickle cell disease (SCD) is an increasing cause of chronic kidney disease, but the spectrum of glomerular lesions and their underlying mechanisms remain poorly described. We reviewed 18 renal biopsies from patients with SCD and glomerular involvement and studied the expression of hypoxic markers in the biopsy specimens. Four histopathologic variants were distinguished: focal segmental glomerulosclerosis (FSGS) (39%), membranoproliferative glomerulonephritis (28%), thrombotic microangiopathy glomerulopathy (17%), and specific sickle cell disease glomerulopathy (17%). Chronic organ damage and history of acute chest syndrome were associated with the occurrence of SCD glomerulopathy. All patients exhibited macroalbuminuria but only 6 patients displayed impaired renal function. SCD was not associated with a specific FSGS histologic variant. Long-term follow-up analysis revealed that 50% of patients exhibited chronic kidney disease. Regardless of the histologic variants, immunohistochemistry did not reveal a specific induction of hypoxic markers (inducible nitric oxide synthase [iNOS], nitrotyrosine, hypoxia-inducible factor [HIF]-1 alpha) at the time of renal biopsy. This large study shows that a wide spectrum of glomerular lesions is associated with SCD. Whatever lesions are observed, the renal prognosis is poor, and early renoprotective treatment is necessary. Hypoxic state does not seem to play a key role in the progression of glomerular lesions, but its potential role at an early stage of glomerular injury requires further investigation.

[Autoimmune myelofibrosis with dermatomyositis]

We report a second observation of autoimmune myelofibrosis associated with an inflammatory myositis in a 30-year-old female. The links between myelofibrosis and autoimmunity are discussed.

Ritonavir-boosted protease inhibitor monotherapy for the treatment of HIV-1 infection

Guidelines for the use of antiretrovirals for HIV-1 infection recommend combining at least three agents. Toxicities, cost, and the complexity of such regimens warrant the search for other options. Boosted protease inhibitor monotherapy is one of the appealing options being investigated. Herein we review uncontrolled and controlled clinical trials evaluating boosted protease inhibitor monotherapy in several clinical settings: maintenance therapy, induction-maintenance strategies, and first-line treatment. Boosted lopinavir monotherapy has been largely investigated in maintenance and induction-maintenance strategies, showing its ability to maintain viral suppression in the majority of participants. The major concern is the higher proportion of patients experiencing transient episodes of low-level viremia (HIV-RNA 50-500 copies/ml) when compared to classical triple regimens. No protease inhibitor-associated resistance mutation was detected in patients who failed on boosted lopinavir monotherapy. Three uncontrolled maintenance strategy studies with boosted atazanavir monotherapy showed conflicting results. Thus, the reassuring results obtained with lopinavir might not be extended to the whole protease inhibitor class, warranting further studies with new generation protease inhibitors such as darunavir. Finally, one controlled trial comparing first-line boosted lopinavir monotherapy to a standard triple combination showed that the latter outperformed the boosted protease inhibitor monotherapy in this clinical setting. In summary, a boosted protease inhibitor single-agent strategy can maintain continuous plasma HIV-RNA suppression in a large proportion of patients already suppressed on a standard triple combination. The more frequent occurrence of low-level viremia, however, does not allow the widespread use of such a strategy outside of clinical studies at this time.