RESUMEN
Anti-PLA2R antibodies (Ab) are a diagnostic and prognostic biomarker in primary membranous nephropathy (PMN). We assessed the relationship between the levels of anti-PLA2R Ab at diagnosis and different variables related to disease activity and prognosis in a western population of PMN patients. Forty-one patients with positive anti-PLA2R Ab from three nephrology departments in Israel were enrolled. Clinical and laboratory data were collected at diagnosis and after one year of follow-up, including serum anti-PLA2R Ab levels (ELISA) and glomerular PLA2R deposits on biopsy. Univariable statistical analysis and permutation-based ANOVA and ANCOVA tests were performed. The median [(interquartile range (IQR)) age of the patients was 63 [50-71], with 28 (68%) males. At the time of diagnosis, 38 (93%) of the patients had nephrotic range proteinuria, and 19 (46%) had heavy proteinuria (≥8 gr/24 h). The median [IQR] level of anti-PLA2R at diagnosis was 78 [35-183] RU/mL. Anti-PLA2R levels at diagnosis were correlated with 24 h proteinuria, hypoalbuminemia and remission after one year (p = 0.017, p = 0.003 and p = 0.034, respectively). The correlations for 24 h proteinuria and hypoalbuminemia remained significant after adjustment for immunosuppressive treatment (p = 0.003 and p = 0.034, respectively). Higher levels of anti-PLA2R Ab at diagnosis in patients with active PMN from a western population are associated with higher proteinuria, lower serum albumin and remission one year after the diagnosis. This finding supports the prognostic value of anti-PLA2R Ab levels and their possible use in stratifying PMN patients.
Asunto(s)
Glomerulonefritis Membranosa , Hipoalbuminemia , Masculino , Humanos , Femenino , Glomerulonefritis Membranosa/diagnóstico , Pronóstico , Autoanticuerpos , Proteinuria/tratamiento farmacológicoRESUMEN
BACKGROUND: Patients with rheumatic diseases, such as rheumatoid arthritis (RA) and ankylosing spondylitis (AS), encounter significantly higher rates of cardiovascular morbidity and mortality. The renin-angiotensin-aldosterone system maintains hemodynamic stability through blood pressure regulation. When dysregulated, this system has been implicated in various pathological conditions, including cardiovascular events. OBJECTIVES: To investigate the levels of renin and aldosterone in RA and AS patients. METHODS: Three groups were recruited: patients with RA, patients with AS, and healthy controls. Subjects were excluded if they had a diagnosis of hypertension, hyperaldosteronism, or renal artery stenosis, or were taking drugs that might have affected renin levels. Renin and aldosterone levels were measured using commercially available kits. Data were analyzed using univariate analyses and multivariate regression analyses. RESULTS: Fifty-one subjects were enrolled in the study: 15 with RA, 4 with AS, and 32 healthy controls. At the univariate analysis, the three groups differed in age (P = 0.005), renin levels (P = 0.013), and aldosterone-to-renin ratio (P = 0.019). At the post-hoc tests, both AS and RA patients differed from controls for renin levels and the aldosterone-to-renin ratio. At the multivariate regression analysis, AS patients had lower renin values than controls (beta standardized regression coefficient -0.323, P = 0.022). CONCLUSIONS: Patients with RA tended to have lower levels of plasma renin compared to healthy subjects. This finding indicates that the renin-angiotensin-aldosterone system might not be directly involved in the process that results in increased cardiovascular events in rheumatoid arthritis.
Asunto(s)
Aldosterona/sangre , Artritis Reumatoide/sangre , Sistema Renina-Angiotensina/fisiología , Renina/sangre , Espondilitis Anquilosante/sangre , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estudios Prospectivos , Análisis de Regresión , Adulto JovenRESUMEN
We have previously identified in human fibroblasts a multisubunit protein (designated PGB) that specifically bound single-stranded G-rich microsatellite DNA sequences. PGB was later found to be identical, or closely related to translin, an octameric protein that bound single-stranded DNA consisting of sequences flanking chromosomal translocations. Here, we report that recombinant translin binds single-stranded microsatellite repeats, d(GT)n, and G-strand telomeric repeats, d(TTAGGG)n, with higher affinities (Kdis approximately = 2 nM and Kdis approximately = 12.5 nM, respectively, in 100 mM NaCl and 25 degrees C) than the affinity with which it binds a prototypical sequence flanking translocation sites (Kdis approximately = 23 nM). Translin also binds d(GT)n and d(TTAGGG)n overhangs linked to double-stranded DNA with equilibrium constants in the nanomolar range. Formation of DNA quadruplexes by the d(TTAGGG)n repeats inhibits their binding to translin. A further study of the binding parameters revealed that the minimal length of d(GT)n and d(TTAGGG)n oligonucleotides that a translin octamer can bind is 11 nucleotides, but that such oligonucleotides containing up to 30 nucleotides can bind only a single translin octamer. However, the oligonucleotides d(GT)27 and d(TTAGGG)9 bind two octamers with negative cooperativity. Translin does not detectably bind single-stranded d(GT)n sequences embedded within double-stranded DNA. Based on our data, we propose that translin might be involved in the control of recombination at d(GT)n.d(AC)n microsatellites and in telomere maintenance.