Gamma interferon release assays (IGRAs) are increasingly used for latent Mycobacterium tuberculosis infection (LTBI) screening in patients with rheumatic diseases starting anti-tumor necrosis factor (anti-TNF) therapies. We compared the performances of two IGRAs, an enzyme-linked immunospot release assay (T-SPOT.TB) and an enzyme-linked immunosorbent assay (QuantiFERON-TB Gold In Tube [QFT-GIT]), to that of tuberculin skin testing (TST) for LTBI screening of 157 consecutive rheumatic patients starting anti-TNF therapies. Among 155 patients with valid results, 58 (37%) were positive by TST, 39 (25%) by T-SPOT.TB assay, and 32 (21%) by QFT-GIT assay. IGRAs were associated more strongly with at least one risk factor for tuberculosis (TB) than TST. Risk factors for a positive assay included chest X-ray findings of old TB (TST), advanced age (both IGRAs), origin from a country with a high TB prevalence, and a positive TST (T-SPOT.TB assay). Steroid use was negatively associated with a positive QFT-GIT assay. The agreement rate between IGRAs was 81% (kappa rate ‫؍‬ 0.47), which was much higher than that observed between an IGRA and TST. If positivity by either TST or an IGRA was required for LTBI diagnosis, then the rate of LTBI would have been 46 to 47%, while if an IGRA was performed only for TST-positive patients, the respective rate would have been 11 to 17%. In conclusion, IGRAs appear to correlate better with TB risk than TST and should be included in TB screening of patients starting anti-TNF therapies. In view of the high risk of TB in these patients, a combination of one IGRA and TST is probably more appropriate for LTBI diagnosis.The accurate diagnosis of latent Mycobacterium tuberculosis infection (LTBI) is critical for patients with various autoimmune diseases who are starting anti-tumor necrosis factor (anti-TNF) therapies, since the majority of tuberculosis (TB) cases developing in this population are due to LTBI reactivation (1.5 to 4 times increased risk) (18)(19)(20). Traditional methods for LTBI diagnosis, such as the tuberculin skin test (TST), have well-known limitations regarding their sensitivity and specificity for LTBI diagnosis (18)(19)(20). Over the last decade, different gamma interferon (IFN-␥) release assays (IGRAs) have been approved for LTBI diagnosis (13). These assays detect IFN-␥ secreted by peripheral mononuclear cells after in vitro stimulation with specific M. tuberculosis antigens not present in the M. bovis bacillus Calmette-Guérin (BCG) vaccine, either by enzyme-linked immunosorbent assay (ELISA) (QuantiFERON-TB Gold [QFT-G] and QuantiFERON-TB Gold In Tube [QFT-GIT] assays; Cellestis Limited, Carnegie, Victoria, Australia) or by enzyme-linked immunospot assay (T-SPOT.TB assay; Oxford Immunotec, Oxford, United Kingdom). Newer techniques for the diagnosis of LTBI or active TB based on the secretion of IFN-␥ after specific stimulation with specific M. tuberculosis antigens, such as the heparinbinding hemagglutinin (HBHA), have also shown promising results (28).Although there have b...

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Abiotic stress is one of the key parameters affecting plant productivity. Drought and soil salinity, in particular, challenge plants to activate various response mechanisms to withstand these adverse growth conditions. While the molecular events that take place are complex and to a large extent unclear, the plant hormone abscisic acid (ABA) is considered a major player in mediating the adaptation of plants to stress. Here we report the identification of an ABA-insensitive mutant from Arabidopsis thaliana. A combination of molecular, genetic and physiology approaches were implemented, to characterise the AtRASD1 locus (RESPONSIVENESS TO ABA SALT AND DROUGHT 1) and to investigate its role in plant development. RASD1 is expressed predominantly in the vascular system of A. thaliana and encodes a peptide of unknown function with no similarity to any known sequence to date. The protein is localised in the nucleus and the cytoplasm, and RASD1-impaired plants are drought-intolerant and insensitive to exogenous ABA and NaCl during germination and root growth. Our data indicate that RASD1 is involved in ABA-dependent signal transduction pathways and therefore in enabling plants to activate response mechanisms related to seed germination and abiotic stress.

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