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B cells, follicular helper T (Tfh) cells and follicular regulatory T (Tfr) cells are part of a circuit that may play a role in the development or progression of rheumatoid arthritis (RA). With the aim of providing further insight into this topic, here we evaluated the frequency of different subsets of Tfh and Tfr in untreated and long-term treated RA patients from a cohort of Argentina, and their potential association with particular human leukocyte antigen (HLA) class-II variants and disease activity. We observed that the frequency of total Tfh cells as well as of particular Tfh subsets and Tfr cells were increased in seropositive untreated RA patients. Interestingly, when analyzing paired samples, the frequency of Tfh cells was reduced in synovial fluid compared to peripheral blood, while Tfr cells levels were similar in both biological fluids. After treatment, a decrease in the CCR7loPD1hi Tfh subset and an increase in the frequency of Tfr cells was observed in blood. In comparison to healthy donors, seropositive patients with moderate and high disease activity exhibited higher frequency of Tfh cells while seropositive patients with low disease activity presented higher Tfr cell frequency. Finally, we observed that HLA-DRB1*09 presence correlated with higher frequency of Tfh and Tfr cells, while HLA-DRB1*04 was associated with increased Tfr cell frequency. Together, our results increase our knowledge about the dynamics of Tfh and Tfr cell subsets in RA, showing that this is altered after treatment.

Background: Parasitic infections by Trypanosoma cruzi (T. cruzi) are frequent in children from endemic areas. Specific therapies have been successfully used in pediatric populations to treat this disease. T. cruzi diagnosis should be optimized and become available for any clinical environment.Objective: To study T. cruzi prevalence in children from an area of active transmission and carry out a post-treatment follow-up. To verify the feasibility of detecting DNA ofT. cruzi from dried blood spot.Methods: We analyzed presence of T. cruzi in 78 Aboriginal children (Toba community) that attended to a rural school of Chaco province, Argentina. Serum and whole blood (dried blood spot) were assessed by means of serological techniques and PCR. Positive children received Benznidazole. Diagnosis and post treatment follow-up of T. cruzi infection were performed.Results: The serology assay showed infection in 34 of 78 (43.5%) children studied; PCR was positive in 5/34, displaying parasitemia. Serology remained positive in 28/28 children 120 days post-treatment, while PCR was positive in 18/28 (6/34 children were lost in follow-up). No adverse effects during the treatment were reported.Conclusions: We were able to establish T. cruzi prevalence in the studied population and also to prove the usefulness of dried blood spot for T. cruzi detection using PCR in isolated areas. This method allowed us to verify early treatment failure. Possible causes of this failure are discussed below.

Introducción. El autoimplante esplénico aparece como la única alternativa para preservar tejido esplénico luego de la esplenectomía, aunque su utilidad sigue siendo discutida. Nos propusimos investigar el autoimplante esplénico en epiplón y pared gástrica de conejos, sus efectos hematoinmunológicos y el mantenimiento de su estructura original. Métodos. Se emplearon conejos Nueva Zelanda los cuales fueron divididos en dos grupos: autoimplante (A) (n=13) y esplenectomía (E) (n=4). En el grupo A se realizó autoimplante de fragmentos esplénicos en epiplón mayor y estómago. Ambos grupos fueron sujetos a valoración prequirúrgica y postquirúrgica a los 2 y 4 meses mediante estudios hemocitológicos, centellografía, dosaje de inmunoglobulinas y C3. Al cuarto mes los injertos fueron sometidos a estudio histológico y genético mediante el rearreglo de genes de receptores de linfocitos B por reacción en cadena de la polimerasa (PCR) para valorar la diversidad de clones de esta célula. Resultados. El estudio histológico evidenció tejido esplénico en 10 de 13 casos (77%). El autoimplante en estómago no presentó complicaciones y demostró mayor correspondencia morfológica al tejido autoimplantado. Ambos grupos presentaron descenso significativo de IgM e incremento de C3, aunque sin diferencias significativas entre ellos. De 8 injertos estudiados por PCR, se confirmó policlonalidad en 3 y oligoclonalidad en 5. Conclusiones. Los autoimplantes se revascularizaron mostrando tejido esplénico en regeneración, probablemente asociado a la oligoclonalidad hallada por PCR. Consecuentemente consideramos que el autoimplante sería una alternativa factible en pacientes esplenectomizados, aunque la ubicación gástrica de los implantes y la elevada frecuencia de oligoclonalidad hallada justifican mayor investigación.

Chronic allograft nephropathy (CAN) represents an important cause of graft loss after kidney transplantation. TGF-ß1 is a key factor in fibrogenesis, and the angiotensin II receptor antagonist losartan may decrease the intra-graft synthesis of TGF-ß1. The aim of this study was to determine the clinical and molecular effect of losartan in kidney transplant patients (KTPs) with CAN. We studied nine KTPs, after the first year of transplantation, with proteinuria (more than 500 mg/24 h), stable renal function, and histological signs of CAN. Immunosuppression was cyclosporine, azathioprine, and corticoids. Kidney biopsy was performed in all patients at the beginning of the study and 12 weeks after treatment with 50 mg/day of losartan. Quantitation of intra-graft expression of TGF-ß1 was performed in all biopsies, by real-time PCR. After losartan treatment there were no differences in patients’ BP and blood creatinine level. The proteinuria significantly dropped to 414.2±377 mg/24 h, P=0.001. Intra-graft expression of TGF-ß1 was decreased after treatment. In conclusion, losartan significantly decreases the intra-graft expression of TGF-ß1 and proteinuria in KTPs with CAN. [ABSTRACT FROM AUTHOR]