Thus, depletion experiments using anti-CD25 mAbs for the study of the role of Tregs during infection models should be thoroughly evaluated in order to avoid misleading conclusions. This work was supported by grant IN-200608 from PAPIIT (DGAPA, UNAM, Mexico), and by grants 79775, 102399 and 102984 from CONACYT (Mexico). We are grateful to MVZ Georgina Díaz and MVZ Jorge Omar García for their expert advice and help in the care of the animals. E.P.T. is recipient of a PhD fellowship BI 2536 cost from CONACYT (Registro 199991). This work was performed in partial fulfillment

of the requirements for the PhD Program of Doctorado en Ciencias Biomédicas of E.P.T. at the Universidad Nacional Autónoma de México. “
“A previous study has suggested that the combination KIR2DS2+/KIR2DL2- was related to

increased risk for systemic sclerosis (SSc), while others have failed to reproduce this finding. Our objective was to study this matter further and test the association of other KIR genes with SSc. One hundred and ten SSc patients and 115 healthy bone marrow donors were enrolled in a case–control study. Blood was collected for DNA extraction; typing of 15 C646 KIR genes and human leucocyte antigen-C (HLA-C) was made by polymerase chain reaction with sequence specific primers (PCR–SSP), followed by electrophoresis on agarose gel. Patients underwent clinical evaluation, serology, Doppler echocardiography and chest high-resolution computed tomography. The frequency of the inhibitory KIR2DL2 was significantly lower in patients [29·1% versus 65·2% in controls, P < 0·0001; odds ratio (OR) = 0·22, 95% confidence interval 0·12–0·40]. When combinations of activating and inhibitory KIR genes were analysed,

the presence of KIR2DS2 in the absence of KIR2DL2 (KIR2DS2+/KIR2DL2-) was more frequent in patients than in controls (25·5% versus 1·7%, respectively; P < 0·0001; OR = 19·29, 4·24–122·26). However, the presence of both KIR2DS2 Suplatast tosilate and KIR2DL2 (KIR2DS2+/KIR2DL2+) was more frequent in controls (57·4%) than in patients (28·2%, P < 0·0001), suggesting a preponderant protective effect of KIR2DL2 over KIR2DS2. Stratification for HLA-C1 status did not change these results. No statistically significant associations were found between KIR phenotypes and clinical and laboratory features of SSc. Our results suggest a protective role of KIR2DL2+ phenotype and confirmed the association of the combination KIR2DS2+/KIR2DL2- with increased risk for SSc. Systemic sclerosis (SSc) is a diffuse connective tissue disease characterized by autoimmunity, vascular dysfunction and variable degrees of fibrosis in the skin and internal organs. Its pathogenesis is not well known, but evidence suggests an inappropriate activation of the immune system triggered by some environmental stimuli in individuals with a genetic background of susceptibility [1].