Les lipodystrophies secondaires aux traitements antirétroviraux de l’infection par le VIH

Les traitements antirétroviraux de l’infection par le VIH sont responsables d’effets secondaires parfois sévères qui touchent en priorité le tissu adipeux, modifiant sa localisation (lipodystrophie avec lipoatrophie périphérique et hypertrophie centrale) et les paramètres du métabolisme glucido-lipidique (dyslipidémie, diabète). Les deux principales classes thérapeutiques, inhibiteurs de protéase et analogues nucléosidiques, sont délétères sur ces paramètres par des mécanismes différents mais qui convergent sur le tissu adipeux. Certaines des molécules de ces deux classes modifient profondément sa différenciation, son métabolisme, sa fonction mitochondriale et l’équilibre des hormones (leptine, adiponectine) et cytokines (TNFα, IL-6) qu’il sécrète. Ce syndrome de lipodystrophie induit un risque cardiovasculaire et de stéatohépatite grevant le pronostic vital. Le traitement reste difficile chez les patients atteints et privilégie le remplacement des molécules les plus délétères par des molécules antirétrovirales plus récentes et moins agressives sur le tissu adipeux.HIV infection requires the continuous administration of antiretroviral molecules. Individual molecules belonging to the two main classes, protease inhibitors (PIs) and nucleoside analogues inhibitors of the viral reverse transcriptase (NRTIs) have been shown to be involved in deleterious side effects collectively called the lipodystrophy syndrome. This syndrome associates altered body fat repartition (peripheral lipoatrophy and visceral fat hypertrophy) and metabolic alterations (dyslipidemia, insulin resistance and diabetes). The pathophysiology of these alterations is complex but different studies argue for adipose tissue being a target of some PIs and NRTIs acting through different mechanisms. NRTIs are able to induce mitochondrial dysfonction and to modify adipocyte phenotype and adipose tissue pattern of secretion of cytokines (TNFα, IL-6) and other adipokines (adiponectin, leptin) probably through the production of reactive oxygen species. Some PIs also act on adipocyte, alter its differentiation and insulin sensitivity and also the pattern of secretion of adipokines by adipose tissue. These hypotheses could explain the loss of adipose tissue, while the mechanisms of visceral fat hypertrophy remain speculative. Since some adipokines and the free fatty acids released by adipocytes play a major role in the control of liver and muscles insulin sensitivity, these alterations are probably involved in the metabolic alterations seen in the patients. In addition, lipodystrophic adipose tissue could be involved in the increased lesions of atherogenesis and steatohepatitis presented by these patients. The treatment of lipodystrophy remains difficult and, at present, privileges the switch of the more deleterious drugs towards new molecules less aggressive for adipose tissue

Communauté des coléoptères d’un littoral sableux méditerranéen : la plage de Bou-Areg (Maroc)

The authors study the four biotopes distingued on a sandy bar of the moroccan mediterranean littoral : the beach, the sandy-dune, the sansouire and the Nador lagoon bank. After description of differents biotopes, the species general inventory (134 Beetles) is established. The populations of the differents biotopes are analysed and compared with the JACCARD’s index. The sandy and the ripicoly communities have been compared with those of the atlantic littoral.Les auteurs étudient les quatre biotopes sur une barre sableuse du littoral méditerranéen marocain : la plage, la dune, la sansouire et la rive de la lagune de Nador. Après description des différents biotopes, l’inventaire faunistique global (134 espèces de Coléoptères) a été établi. Les peuplements des différents biotopes ont été analysés et comparés par l’indice de JACCARD. Les communautés ripicoles et sabulicoles ont été comparées avec celles du littoral atlantique.Maachi Mustapha, Radouani Mohamed. Communauté des coléoptères d’un littoral sableux méditerranéen : la plage de Bou-Areg (Maroc). In: Ecologia mediterranea, tome 19 n°1-2, 1993. pp. 29-38

Inappropriately low glycated hemoglobin values and hemolysis in HIV-infected patients.: Glycated hemoglobin in HIV - infected patients

International audienceIn order to test the accuracy of glycated hemoglobin (HbA1c) in predicting mean glycemia in HIV-infected patients, we recorded consecutive HbA1c measurements from 1238 non-HIV-infected and 112 HIV-infected patients, all devoid of any hemoglobinopathy, in a retrospective, transversal study. Mean fasting glycemia from the six previous weeks (measured-Gly) and HbA1c-estimated glycemia [HbA1c-Gly (1.85x%HbA1c-4.78) mM] were compared. Mean hemoglobin, red cell volume, serum creatinine, CD4 count, and HIV viral load from the same period were collected in HIV-infected patients. Although measured-Gly was not significantly different between non-HIV-infected (6.95+/-3.23 mM) and HIV-infected patients (6.62+/-2.42 mM), HbA1c underestimated the mean fasting glycemia by 12.3% in HIV-infected as compared to non-HIV-infected patients (p=0.0001). The difference "measured-Gly-HbA1c-Gly" was correlated with the red cell volume (p<0.0001) in HIV-infected patients. We then searched for the presence of subclinical hemolysis, a cause of both macrocytosis and reduced HbA1c levels, in HIV-infected patients. To this end, we prospectively measured serum haptoglobin in 249 consecutive samples from HIV-infected subjects without any known cause of hemolysis. A very low haptoglobin level, a marker of hemolysis, was frequent and negatively correlated with the red cell volume in these patients. Treatment with nucleoside analogues was significantly associated with macrocytosis and low haptoglobin. In conclusion, HbA1c could be inappropriately low in HIV-infected patients. Its underestimation of mean fasting glycemia could be due to an antiretroviral-induced subclinical hemolysis, but further studies are needed to explore this hypothesis. Self-monitoring of blood glucose and search for latent hemolysis should be promoted in diabetic HIV-infected patients