Injection drug use facilitates hepatitis C virus infection of peripheral blood mononuclear cells.

Infection of peripheral blood mononuclear cells (PBMCs) with hepatitis C virus (HCV) has been demonstrated and has been found to play a role in relapse of HCV disease and vertical transmission of HCV. Injection drug use is thought to impair function of the immune system and induce tolerance to viruses; therefore, HCV infection of PBMCs could be more likely to occur in injection drug users (IDUs) with HCV infection. Of 108 women who tested negative for human immunodeficiency virus type 1 and positive for HCV RNA, 51 had a history of injection drug use and 57 had no known risk factor for HCV infection. HCV infection was found, by nested reverse-transcription polymerase chain reaction analysis, in the PBMCs of 33 IDUs and of 13 non-IDUs (P=.00003). No correlation was found between infection of the PBMCs and HCV genotype or virus load. Route of transmission and viral factors, as well as immunologic dysfunction, may play a role in viral tropism.

Th17 transcription factor RORC2 is inversely correlated with FOXP3 expression in the joints of children with juvenile idiopathic arthritis.

OBJECTIVE: To investigate the relationship between interleukin 17 (IL-17) producing T cells (Th17) and CD4+CD25+FOXP3+ regulatory T cells (Tregs) in blood and synovial fluid (SF) of patients with juvenile idiopathic arthritis (JIA). METHODS: Sixty-five children with JIA (18 males and 47 females, median age 6.2 yrs; 45 with oligoarticular and 20 with polyarticular course) and 75 age- and sex-matched healthy controls were studied. Flow cytometry was used to analyze the forkhead box P3 (FOXP3)-positive Treg cells in peripheral blood (PB) and synovial fluid mononuclear cells (SFMC). FOXP3 and retinoic-acid related orphan receptor C isoform 2 (RORC2) messenger RNA (mRNA) were assessed by real-time polymerase chain reaction analysis. Cytokines (IL-17 and Th1/Th2 related cytokines) were measured in culture supernatants of 11 paired PBMC and SFMC activated with PMA and ionomycin. RESULTS: FOXP3+ T cells and FOXP3 mRNA amounts were significantly lower in PB of children with JIA as compared with controls (p = 0.0002 and p = 0.001, respectively) and a higher percentage of Treg cells with concomitant higher level of FOXP3 transcript levels were observed in SF when compared with their PB counterparts (both p < 0.0001). SF CD4+FOXP3+ T cells were characterized by higher amounts of FOXP3 protein per cell when compared with peripheral CD4+FOXP3+ T cells, as revealed by the difference in FOXP3 median fluorescence intensity (median +/- SD, arbitrary units, 54 +/- 22.6 vs 19.5 +/- 4.2; p < 0.001). RORC2 transcript levels were higher in JIA joints when compared with matched PB samples (median fold increase 3.9, p < 0.0001) but negatively correlated with FOXP3 mRNA levels (r = -0.623, p = 0.04). Stimulated SFMC displayed an impaired ability to produce IL-17 when compared with PBMC and, interestingly, an inverse relationship between IL-17 levels and the percentage of CD4+CD25+FOXP3+ SF T cells (r = -0.510, p = 0.047) was seen. CONCLUSION: We demonstrated for the first time an increased synovial expression of the transcription factor of Th17, RORC2, in JIA, and its inverse relationship with FOXP3 mRNA. These results extend research on "Th17" and Tregs in JIA.

Higher risk of hepatitis C virus perinatal transmission from drug user mothers is mediated by peripheral blood mononuclear cell infection.

Maternal injection drug use and peripheral blood mononuclear cell infection by hepatitis C virus are important risk factors for perinatal transmission of the virus. The aim of present study was to evaluate the independent association of these two factors on perinatal transmission. Forty-eight consecutive mothers who transmitted infection to their offspring and 122 consecutive mothers who did not, together with their children, were examined. Both maternal injection drug use and peripheral blood mononuclear cell infection were significantly more frequent in infected than in uninfected children (respectively P = 0.04; odds ratio 2.33, 95% confidence intervals 1.02-5.42 and P < 10(-6); odds ratio and 95% confidence intervals not calculable due to zero values). Multivariate analysis confirmed the link between maternal peripheral blood mononuclear cell infection and perinatal transmission (P < 10(-6); odds ratio and 95% confidence intervals not calculable due to zero values) but no association was found with maternal injection drug use. The high risk of perinatal transmission found in injection drug use mothers is dependent on maternal peripheral blood mononuclear cell infection by hepatitis C virus. Peripheral blood mononuclear cell infection represents one of the most important risk factors for hepatitis C virus perinatal transmission.

Safety and immunogenicity of measles-mumps-rubella vaccine in children with congenital immunodeficiency (DiGeorge syndrome).

Live attenuated vaccines are usually contraindicated in patients with congenital or acquired immunodeficiency. On the other hand, infections due to wild type virus may be particularly severe in patients with low levels of T cells. The aim of the present study was to evaluate safety and immunogenicity of measles-mumps-rubella (MMR) vaccine in children with congenital T cell defect (DiGeorge anomaly). Fourteen patients were included in the study. No severe adverse reaction was reported. No difference between patients and controls was found in frequency of seroconversion for both measles (92.9% versus 96.3%) and rubella (92.9% versus 100%). No difference in mean titres of anti-measles (1.62+/-0.54 versus 1.89+/-0.49 index) (p=0.13) or anti-rubella (78.1+/-48.0 versus 72.0+/-41.0 UI/ml, p=0.68) antibodies was found between patients and controls. No decrease in CD4 cells was detected after immunization. MMR vaccine is immunogenic and can be safely used in patients with DiGeorge anomaly, so preventing severe complication due to wild virus infection.