The aim of our study was to investigate and characterize regulatory T cells (Treg) in peripheral blood of patients with connective tissue diseases (Systemic lupus erythematosus, systemic sclerosis, Sjögren's syndrome, poly- and dermatomyositis) as compared with blood from healthy controls. Treg cells were quantified and phenotypically characterized by flow cytometry while the expression level of Foxp3 mRNA was evaluated by real time PCR. A reduced percentage of peripheral blood Treg cells was found in patients than in controls, irrespective of the type of connective tissue disease. Treg cells, especially those expressing one of the phenotypical markers, seemed to differ not only between patients and healthy controls but also among types of diseases. Additionally, the presence of autoantibodies as well as disease activity appeared to be correlated with particular Treg cell populations, especially those expressing one of the examined phenotypical markers. Correlations with therapy suggested that glucocorticoids plus antimalarial or other immunosuppressor drugs diminished the percentage of Treg cells, especially of those with memory phenotype. These findings indicated dysregulations at the level of Treg cells and suggested an involvement of these cells in the pathology of connective tissue diseases. Moreover, our data are in agreement with the suggestion that Treg cells could be therapeutic targets for some autoimmune diseases.

Since 2011, Romania has faced an HIV outbreak among injecting drug users (IDUs). Our aim was to identify and describe clinical and epidemiological patterns of this outbreak. A cross-sectional study enrolled 138 IDUs diagnosed with HIV infection between 2011 and 2013 with 58 sexually infected individuals included as the control group. The IDUs had a long history of heroin abuse (10 years) and a recent history of new psychostimulant injection (3–4 years). Classical epidemiological data and molecular techniques were used to describe the transmission dynamics. A high prevalence of hepatitis C virus (HCV) coinfection was noted (98.6%) compared to the control group (10.3%) ( p <0.001). IDUs had initially been infected with HCV. HIV infection was more recent, linked to starting injecting stimulants. HIV subtype analysis showed a predominance of the local F1 strain in both IDUs and sexually infected patients; in IDUs it also identified 28 CRF14_BG recombinants and six unique recombinant forms (URFs) between F1 and CRF14_BG. A few patients from both risk groups were infected with subtype B. Among IDUs, CRF14_BG was associated with a lower CD4 cell count and more advanced stages of disease, which correlated with CXCR4 tropism. Phylogenetic analysis revealed the spread of HIV through three major IDU clusters of recent date. Among IDUs with CRF14_BG, some reported travel abroad (Spain, Greece). By identifying clusters of IDUs with related viruses, molecular epidemiologic methods provide valuable information on patterns of HIV transmission that can be useful in planning appropriate harm reduction interventions.

It was suggested that the immune system plays an important role at least in the amplification of the main elements in systemic sclerosis (SSc), an autoimmune disease with an incompletely elucidated pathogenesis. Elucidation of the mechanisms involved in the interaction between T and B cells, major players of the immune system, could contribute to a better understanding of some of clinical and pathological manifestations of SSc. Recently, abnormalities in Semaphorin 4D (Sema4D/CD100) or CD72, two contrareceptors involved in T and B cells cooperation, were associated with autoimmunity. Therefore, we investigated CD100 and CD72 expression level on T and B cells in attempting to establish their role in SSc pathogenesis. The results revealed augmented percentages of CD100^high T and B cells, significantly increased expression of CD100 on CD4⁺ T cells and frequently detectable levels of soluble CD100 in SSc patient sera compared to healthy donors. In SSc, CD100 dysregulations were associated with anti-Scl70 antibodies production, disease type, thickening of skin, disease duration, or with active inflammation processes. In consequence, dysregulations in CD100 expression and release could play a role in SSc development and/or maintenance.

Co-infections with HIV and HCV are very frequent among people who inject drugs (PWID). However, very few studies comparatively reconstructed the transmission patterns of both viruses in the same population. We have recruited 117 co-infected PWID during a recent HIV outbreak in Romania. Phylogenetic analyses were performed on HIV and HCV sequences in order to characterize and compare transmission dynamics of the two viruses. Three large HIV clusters (2 subtype F1 and one CRF14_BG) and thirteen smaller HCV transmission networks (genotypes 1a, 1b, 3a, 4a and 4d) were identified. Eighty (65%) patients were both in HIV and HCV transmission chains and 70 of those shared the same HIV and HCV cluster with at least one other patient. Molecular clock analysis indicated that all identified HIV clusters originated around 2006, while the origin of the different HCV clusters ranged between 1980 (genotype 1b) and 2011 (genotypes 3a and 4d). HCV infection preceded HIV infection in 80.3% of cases. Coincidental transmission of HIV and HCV was estimated to be rather low (19.65%) and associated with an outbreak among PWID during detention in the same penitentiary. This study has reconstructed and compared the dispersion of these two viruses in a PWID population.