Counter-intuitive plasma vitamin D and zinc status in HIV-1-infected adults with persistent low-level viraemia after treatment initiation: a pilot case-control study.

Determinants of persistent low-level viraemia [PLLV, a viral load (VL) of between 50 and 500 copies/mL] have not been elucidated. In a case-control study, we evaluated the influence of micronutrients on PLLV in a population of 454 HIV-1 adults having initiated antiretroviral therapy (ART) between January 2007 and December 2011. Plasma levels of retinol (vitamin A), 25-OH vitamin D2 + D3, vitamin E and zinc were measured at ART initiation in cases (PLLV after 6 months of ART) and in controls (VL <50 copies/mL after 6 months). Cases and controls were matched for the CD4 cell count (±50/mm3) and ethnic origin. Intergroup differences in demographic, biological and treatment parameters and sunshine intensity at ART initiation were adjusted using a propensity score. A receiver operating characteristic (ROC) curve was used to assess intergroup differences in plasma micronutrient levels. Thirty-three of the 454 patients (7.3%) displayed PLLV (median VL: 92 copies/mL). Patients were predominantly male (89%), Caucasian (64%) and CDC stage C (25%). The median age was 38 years, the median initial VL was 5.2 log10 copies/mL and the median CD4 count was 74/mm3. The 22 cases and matched controls were balanced in these respects, and had similar vitamin A/E levels. Two cases (9%) and 9 controls (41%) had a vitamin D level <10.3 ng/mL (p = 0.0015), and 2 cases (9%) and 10 controls (48%) had a zinc level <74.6 µg/dL (p = 0.04). Our results support in vitro studies suggesting that vitamin D favours HIV-1 replication and that HIV-1 is zinc-dependent. Wide-scale, prospective studies are required.

[Value of the early determination of plasma myoglobin level in the diagnosis of acute myocardial infarction]. / Intérêt des dosages précoces de la concentration sérique de la myoglobine pour le diagnostic de l'infarctus du myocarde en voie de constitution.

Serum myoglobin (Mb) was assayed by immuno-nephelemetry or immuno-turbidimetry together with creatinine kinase activity (CK) by spectrophotometry in 290 consecutive patients admitted to hospital between January 1st and September 30th 1992 in three cardiology departments for chest pain suggesting myocardial infarction (MI). The measurements were made at admission (T0) and 90 minutes later (T90). On admission, patients were classified as certain MI (N = 62), possible MI (N = 107) or definitely not MI (N = 121) and, on discharge, as certain MI (N = 144) or definitely not MI (N = 146). At T0, for a threshold value of 90 mcg/l, Mb assay had a sensitivity of 49.3% and a specificity of 95.2%, a positive predictive value of 91.8% and a negative predictive value of 65.6%. Increasing the threshold of positivity to 130 mcg/l was accompanied by a significant loss of sensitivity (38.2%) without any change in the other parameters. At T90, for a threshold value of 90 mcg/l, Mb assay had a sensitivity of 81.7%, a specificity of 92%, a positive predictive value of 89.5% and a negative predictive value of 85.8%. The increase in sensitivity between T0 and T90 made Mb assay very useful for correctly classifying the initial false negative results (20/28: 71.4%) and for diagnosing the possible MI (27/32: 84.4%). Decreasing the threshold of positivity to 80 or even to 70 mcg/l did not improve the diagnostic value of this test. The sensitivity of Mb assay was significantly higher than that of CK at T0 (49.3% vs 26.4%: p < 0.0001) and at T90 (81.7% vs 48.9%: p < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

[Glycosylated plasma proteins in chronic renal failure]. / Protéines glyquées plasmatiques dans l'insuffisance rénale chronique.

In chronic renal failure HbA1c values and plasma fructosamine concentrations are difficult to interpret owing to anaemia (for HbA1c) and analytical interferences (for fructosamine test). Plasma proteins glycation was measured more specifically by affinity chromatography. Glycated albumin, glycated immunoglobulins G and glycated proteins were determined in 30 control patients, 30 diabetics and 28 patients with chronic renal failure divided into 17 non diabetics and 11 diabetics. Glycated albumin, glycated IgG and glycated total proteins were not modified by chronic renal failure in non diabetic patients on the contrary of HbA1c and fructosamine test.