Impact of the introduction of a nucleic acid amplification test for Clostridium difficile diagnosis on stool rejection policies.

BACKGROUND: The change from non-molecular to nucleic acid amplification tests (NAATs) is known to increase the detection of Clostridium difficile infection (CDI); however, the impact on stool rejection policies in clinical laboratories is unclear. The current guidelines have reinforced the importance of respecting strict conditions for performing tests on stool samples for CDI diagnosis. The purpose of this study was to estimate whether the implementation of molecular tests has resulted in changes in stool rejection policies between clinical laboratories that introduced NAATs and those that did not. RESULTS: A survey was conducted to evaluate the change in the number of stool samples rejected and the rejection criteria among 12 hospital laboratories in southwestern France before and after the switch from non-molecular tests to NAATs using retrospective data from June 1 till September 30, 2013 and the same period 2014. Four laboratories introduced NAATs as a second or third step in the process. A total of 1378 and 1297 stools samples were collected in 2013 and 2014, respectively. The mean number of rejected stool samples significantly increased (p < 0.001, Chi square test), with a total of 99 (7.1%) and 147 (11.3%) specimens rejected in 2013 and 2014, respectively. Notably, these laboratories had more stringent criteria and were no longer testing the stool samples of patients with CDI-positive results within 7 days. In contrast, there was a significant decrease in the rate of rejected stool samples (p < 0.001, Chi square test) in the five laboratories that did not adopt NAATs and a less stringent stool rejection policy. CONCLUSION: Nucleic acid amplification test implementation improved compliance with recommended stool rejection policies. Laboratories should follow the recommended laboratory algorithm for the CDI diagnosis combined with the correct stool rejection policy.

[Susceptibility genes, HLA and diabetic retinopathy in the Algerian population]. / Gènes de susceptibilité HLA et rétinopathie diabétique chez la population algérienne.

BACKGROUND: Diabetic retinopathy (DR) is the most frequent microvascular complication of type I diabetes (T1D). Some well-controlled type I diabetics may develop DR, while other poorly-controlled diabetics do not develop DR. This might be explained by certain susceptibility genes or protective genes. The purpose of our study is to search for any association between the HLA class I and II markers and DR in the Algerian population. PATIENTS AND METHODS: This study was carried out in 52 T1D subjects with and without DR compared to 140 healthy controls. HLA typing was performed using the "microlymphocytotoxicity" technique. RESULTS: The frequency of HLA-A29 and HLA-DR9 antigens is higher in T1D with DR compared to T1D without DR and to controls with frequencies of HLA-A29 (59.26% vs. 0%, OR=∞, pc=4.6×10(-7)), (59.26% vs. 5.66%, OR=24.24, pc=7.6×10-10) and HLA-DR9 (29.63% vs. 0%, OR=∞, pc=1.310(-3)), (29.63% vs. 4.29%, OR=9.40, pc=7.010(-5)) respectively. However, the frequency of HLA-B49 antigen is significantly lower in T1D with DR than in T1D without DR (3.7% vs. 28%, OR=0.10, pc=8.8×10(-3)) and compared to controls (3.7% vs. 22.64%, OR=0.13, pc=0.011). CONCLUSION: HLA-A29 and HLA-DR9 antigens are probably markers of susceptibility for DR while HLA-B49 antigen is probably associated with a protective effect in the Algerian population.

[Primary hyperaldosteronism]. / Dépistage biologique de l'hyperaldostéronisme primaire. Revue de la littérature.

Diagnosing primary aldosteronism, a hypertensive endocrine disease, is difficult because of an ill-defined frequency, various clinical forms and multiple diagnostic criteria. Current recommendations rest upon aldosterone and renin or renin activity determinations, the main point being to investigate aldosterone secretion with regards to of its main stimulus, renin. Proponents of the renin assay argue that it is easy and reliable. Proponents of the renin activity assay favour this method because of multiple epidemiological studies. Whatever the method used, each laboratory has to establish its critical thresholds in relation to the kits used. Extensive comparative studies would be useful to appreciate their relative benefits.

[Ac-SDKP, a marker of the angiotensin-converting enzyme activity?]. / L'Ac-SDKP: une clé pour comprendre certains effets des inhibiteurs de l'enzyme de conversion?

The tetra-peptide Acetyl-Ser-Asp-Lys-Pro (Ac-SDKP) generated by the cleavage of thymosine beta4 inhibits the proliferation of hematopoietic stem cells and the proliferation and secretion of fibroblasts in the myocardium and the glomeruli. The clinical administration of Ac-SDKP has been proposed and partially investigated. The peptide could protect hematopoietic stem cells during anti-neoplastic treatments leaving cancerous cells unprotected. As it opposes the effects of TGFbeta it could prevent fibrosis after myocardial infarcts and glomeruli fibrosis during the natural course of diabetic nephropathy. However, until now the expected benefits of such a treatment are based on an indirect consideration. Indeed, the degradation of Ac-SDKP is due to the action of the angiotensin-converting enzyme. Interestingly, the blocking of this enzyme both improves the above-mentioned fibrosis and increases the plasma levels of Ac-SDKP. Should the therapeutic effects prove solid, and therapeutic levels be established assaying Ac-SDKP could be an interesting marker of therapeutic efficiency.