Dynamics of circulating follicular helper T cell subsets and follicular regulatory T cells in rheumatoid arthritis patients according to HLA-DRB1 locus.

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.

The HLA-B*51 allele is strongly associated with Behçet Disease in an Argentinean population / El alelo HLA-B*51 se asoció fuertemente a la Enfermedad de Behçet en la población argentina

OBJECTIVE: To assess the association between the HLA-B*51 allele and Behçet Disease (BD) in Argentinean patients. METHODS: We enrolled 34 consecutive Argentinean patients with definitive diagnosis of BD between October 2016 and March 2017. None of the patients had the HLA-B*51 allele determined at study entry. Unrelated controls (n=240) were randomly obtained from the national cadaveric donor database. Demographic and clinical features of the patients were recorded by attending physicians through a questionnaire. RESULTS: Mean age of cases was 42 years old. Nineteen (55.8%) were male, and the mean age at diagnosis was 35 years old; twenty (58.8%) were Mestizos, 8 (23.5%) were Caucasian, and 6 (17.6%) were Amerindians. Thirteen (38.2%) of 34 cases were HLA-B*51 allele positive; 11 were heterozygous and 2 homozygous for the allele. Thirty-four (14.2%) of 240 controls were positive for the HLA-B*51 allele. The association between BD and HLA-B*51 allele was greater than that of control group (OR=3.75; p = 0.0012). CONCLUSIONS: The HLA-B*51 allele is strongly associated with BD in Argentinean patients. Our finding is consistent with previous studies indicating that the HLA-B*51 allele is an important susceptibility gene in BD regardless the geographical region and ethnicity

OBJETIVO: Evaluar la asociación entre el alelo HLA-B*51 y la enfermedad de Behçet (EB) en pacientes argentinos. MÉTODOS: Incluimos en forma consecutiva 34 pacientes argentinos con diagnóstico definitivo de EB entre los meses de octubre de 2016 y marzo de 2017. Ninguno de los pacientes tenía el alelo HLA-B*51 determinado al inicio del estudio. Los controles no relacionados (n=240) se obtuvieron al azar de la base nacional de datos de donantes cadavéricos. Las características demográficas y clínicas de los pacientes fueron registradas por los médicos asistentes a través de un cuestionario. RESULTADOS: La edad promedio de los casos fue de 42 años. Diecinueve (55,8%) fueron varones, y la edad promedio en el momento del diagnóstico fue de 35 años; 20 (58,8%) fueron mestizos, 8 (23,5%) caucásicos y 6 (17,6%) amerindios. Trece (38,2%) de los 34 casos fueron positivos para el alelo HLA-B*51; 11 de ellos fueron heterocigotas y 2 homocigotas para dicho alelo. Treinta y cuatro (14,2%) de los 240 controles fueron positivos para el alelo HLA-B*51. La asociación entre la EB y el alelo HLA-B*51 fue mayor que en el grupo control (OR=3,75; p = 0,0012). CONCLUSIONES: El alelo HLA-B*51 está fuertemente asociado con la EB en pacientes argentinos. Nuestro hallazgo es consistente con estudios previos que indican que el alelo HLA-B*51 es un gen de susceptibilidad importante en la EB independientemente de la región geográfica y la etnia

The HLA-B*51 Allele is strongly associated with Behçet Disease in an Argentinean population.

OBJECTIVE: To assess the association between the HLA-B*51 allele and Behçet Disease (BD) in Argentinean patients. METHODS: We enrolled 34 consecutive Argentinean patients with definitive diagnosis of BD between October 2016 and March 2017. None of the patients had the HLA-B*51 allele determined at study entry. Unrelated controls (n=240) were randomly obtained from the national cadaveric donor database. Demographic and clinical features of the patients were recorded by attending physicians through a questionnaire. RESULTS: Mean age of cases was 42 years old. Nineteen (55.8%) were male, and the mean age at diagnosis was 35 years old; twenty (58.8%) were Mestizos, 8 (23.5%) were Caucasian, and 6 (17.6%) were Amerindians. Thirteen (38.2%) of 34 cases were HLA-B*51 allele positive; 11 were heterozygous and 2 homozygous for the allele. Thirty-four (14.2%) of 240 controls were positive for the HLA-B*51 allele. The association between BD and HLA-B*51 allele was greater than that of control group (OR=3.75; p=0.0012). CONCLUSIONS: The HLA-B*51 allele is strongly associated with BD in Argentinean patients. Our finding is consistent with previous studies indicating that the HLA-B*51 allele is an important susceptibility gene in BD regardless the geographical region and ethnicity.

Frequency of human leukocyte antigens class II-DR alleles (HLA-DRB1) in Argentinian patients with early arthritis.

Patients with rheumatoid arthritis (RA) or undifferentiated arthritis (UA) in the CONAART database (Argentine Consortium for Early Arthritis) were assessed for genetic risk factors for RA, specifically for HLA-DRB1 alleles and the PTPN22 rs2476601 polymorphism associated with progression to RA. This is a case-control study. Blood samples were obtained to determine HLA-DRB1 genotypes by PCR-SSO Luminex and PTPN22 (rs2476601) polymorphism by allelic discrimination. A control group of individuals from the general Argentinian population were obtained from the national register of cadaveric organ donors. A total of 1859 individuals were included in this analysis: 399 patients from the CONAART database (347 patients with RA at study end and 52 patients with UA at study end, mean follow-up time 25 ± 18 months) and 1460 individuals from the general Argentinian population. Compared with the controls, the HLA-DRB1*04 and DRB1*09 alleles were more commonly detected in patients with RA diagnosis (OR (95% CI) 2.23 (1.74-2.85) and 1.89 (1.26-2.81)) respectively. Both patients with UA and the general population showed higher frequency of DRB1*07, DRB1*11 and DRB1*15 alleles than patients with RA. PTPN22 rs2476601 polymorphism frequency was higher in RA and UA vs the general population; however, this was significantly different only for RA vs control group (OR [95% CI] = 1.81 [1.10-3.02], P = 0.018. HLA-DRB1 typing and PTPN22 allelic discrimination could distinguish between patients with UA, patients with early RA, and the general population in Argentina. This is the first study of HLA-DRB1 alleles and PTPN22 polymorphism associations with progression to early RA in an Argentinian population.

Immune thrombocytopenia with antiphospholipid antibodies in monozygotic twins.

We describe monozygotic twins with immune thrombocytopenia (ITP) associated to antiphospholipid antibodies with a dissimilar clinical expression. The first patient was diagnosed to have ITP at 63 years old and was treated with corticosteroids. She presented ulterior exacerbations of thrombocytopenia requiring intravenous immunoglobulin and subsequent treatment with rituximab. She ultimately had a favorable response without thrombotic events during follow-up. The second patient who had a history of three spontaneous abortions and endometrial adenocarcinoma in complete remission was evaluated for severe thrombocytopenia, ITP was diagnosed at the age of 63. She was treated with steroids and had a favorable response. After few months she developed deep venous thrombosis and pulmonary embolism requiring anticoagulation therapy without hemorrhagic events. Both patients were found to have antiphospholipid antibodies and HLA DR4 (DRB1*04) and HLA DR5 (DRB1*12). The association of those two entities in monozygotic twins could support the presence of common predisposing genes. However, with both patients being genotipically identical, the clinical expression was different. Those cases highlight the possibility that environmental factors may affect the expression of those disorders.

Evaluation of gene panel mRNAs in urine samples of kidney transplant recipients as a non-invasive tool of graft function.

Non-invasive monitoring may be useful after kidney transplantation (KT), particularly for predicting acute rejection (AR). It is less clear whether chronic allograft nephropathy (CAN) is also associated with changes in urine cells. To identify non-invasive markers of allograft function in kidney transplant patients (KTP), mRNA levels of AGT, TGF-beta1, EGFR, IFN-gamma, TSP-1, and IL-10 in urine (Ur) samples were studied using QRT-PCR. Ninety-five KTP and 111 Ur samples were evaluated. Patients (Pts) were divided as, within six months (N = 31), and with more than six months post-KT (N = 64). KTP with more than six months post-KT were classified as KTP with stable kidney function (SKF) (N = 32), KTP with SKF (creatinine < 2 mg/dL) and proteinuria > 500 mg/24 h (N = 18), and KTP with biopsy proven CAN (N = 14). F-test was used to test for equality of variances between groups. IL-10 mRNA was decreased in Ur samples from KTP with less than six months post-KT (P = 0.005). For KTR groups with more than six months post-KT, AGT and EGFR mRNA were statistically different among KTP with SKF, KTP with SKF and proteinuria, and CAN Pts (P = 0.003, and P = 0.01), with KTP with SKF having higher mean expression. TSP-1 mRNA levels also were significantly different among these three groups (P = 0.04), with higher expression observed in CAN Pts. Using the random forest algorithm, AGT, EGFR, and TGF-beta1 were identified as predictors of CAN, SKF, SKF with proteinuria. A characteristic pattern of mRNA levels in the different KTP groups was observed indicating that the mRNA levels in Ur cells might reflect allograft function.

Establishing the molecular pathways involved in chronic allograft nephropathy for testing new noninvasive diagnostic markers.

BACKGROUND: Chronic allograft nephropathy (CAN) is a cause of graft loss. The multistage processes that result in CAN are poorly understood. Noninvasive assays for detecting allograft dysfunction and predicting long-term outcomes are a priority in transplantation (Tx). METHODS: Renal tissue from kidney transplant patients (KTP) with CAN (n=11) and normal kidneys (NK; n=7) were studied using microarrays. Markers resulting from the microarray analysis (transforming growth factor [TGF]-beta, epidermal growth factor receptor [EGFR], angiotensinogen [AGT]) were tested in urine (Ur) and peripheral blood (PB) samples from the CAN patients (collected at the biopsy time) using reverse-transcriptase real-time polymerase chain reaction. Ur and PB samples from long-term KTP with stable renal function (SRF; n=20) were used as control. RESULTS: Assuming unequal variances between CAN and NK, using a false discovery rate of 0.005, and running 1,000 of all possible permutations, 728 probe sets were differentially expressed. Genes related to fibrosis and extracellular matrix deposition (i.e., TGF-beta, laminin, gamma 2, metalloproteinases-9, and collagen type IX alpha 3) were up-regulated. Genes related to immunoglobulins, B cells, T-cell receptor, nuclear factor of activated T cells, and cytokine and chemokines receptors were also upregulated. EGFR and growth factor receptor activity (FGFR)2 were downregulated in CAN samples. AGT, EGFR, and TGF-beta levels were statistical different in urine but not in blood samples of CAN patients when compared to KTP with SRF (P<0.001, P=0.04, and P<0.001, respectively). CONCLUSIONS: Genes related to fibrosis, extracellular matrix deposition, and immune response were found up-regulated in CAN. Markers resulting from the microarray analysis were differentially expressed in Ur samples of the CAN patients and in concordance with the microarray profiles.