Study of pathogenic T-helper cell subsets in Asian Indian patients with Takayasu arteritis.

The relapses and refractory disease are a challenge in the management of patients with Takayasu arteritis (TAK). We quantified pathogenic CD4 + memory T helper cells bearing surface markers CD161 and/or p-glycoprotein (MDR1) in patients with TAK. Peripheral blood mononuclear cells of 21 patients with TAK and 16 age-matched controls were stained with anti-CD3, anti-CD4, anti-CD45RA, anti-CD161 and anti-p-glycoprotein antibodies and subjected to flow cytometry by FACS ARIAIII. Eighteen patients underwent follow-up immunophenotyping. Intracellular staining for interleukin-17 and interferon-γ was performed for 18 patients and 11 controls. Surgical arterial biopsies of 6 TAK and 5 non-inflammatory controls were subjected to immunohistochemistry with anti-CD161 and anti-p-glycoprotein. At baseline the frequency of MDR1 + CD4 + and CD161 + MDR1 + CD4 + memory T cells was higher in TAK than controls (p = 0.002 and 0.01, respectively). After stimulation, the frequency of IFN-y + CD161 + cells was higher in TAK than controls (p = 0.028). Modal fluorescence intensity of CD161 + MDR1 + CD45RA - CD4 + cells was higher in active as compared with stable disease (p = 0.041). At 6 months, MDR1 + and CD161 + MDR1 + memory CD4 + T cells decreased significantly only in patients who had complete/partial response to treatment (p = 0.047 and 0.02, respectively). To conclude, MDR1 + and MDR1 + CD161 + CD4 + memory T-helper cells are increased in patients with TAK. These cells decreased only in patients with response to treatment during subsequent follow-up.

Antifungal susceptibility testing of Candida tropicalis biofilms against fluconazole using calorimetric indicator resazurin.

BACKGROUND: C.tropicalis is an important cause of nosocomial infections particularly in immunocompromised patients. Infections caused by Candida spp. are often associated with biofilm formation on implanted medical devices or on epithelial cell surfaces. Phenotypic characteristics of sessile cells in biofilms are known to be different from those of their free-living, planktonic counterparts. Biofilm forming strains often show increased resistance to antimicrobial agents. MATERIALS AND METHODS: We measured susceptibility to fluconazole of fifty C.tropicalis isolates from immunocompromised (29) and immunocompetent (21) patients by minimum inhibitory concentration (MIC) and minimum biofilm inhibitory concentration (MBIC) assays. MBIC was done using the calorimetric indicator resazurin, to measure the metabolically active cells. RESULTS: Biofilm forming cells showed increased resistance to fluconazole. CONCLUSION: The resazurin dye test was found to be a good method for determining MBIC.