Short-chain fatty acids ameliorate experimental anti-glomerular basement membrane disease.

BACKGROUND: Short-chain fatty acids (SCFAs), as the link between gut microbiota and the immune system, had been reported to be protective in many autoimmune diseases by the modulation of T cell differentiation. The pathogenic role of autoreactive Th1 and Th17 cells and the protective role of Treg cells in the pathogenesis of anti-GBM disease have been fully demonstrated. Thus, the present study aimed to investigate the therapeutic effects of SCFAs in a rat model of anti-GBM disease. MATERIALS AND METHODS: Experimental anti-GBM disease was constructed by immunizing Wistar Kyoto rats with a nephrogenic T cell epitope α3127-148, and intervened by sodium acetate, sodium propionate, or sodium butyrate, 150 mM in the drinking water from day 0 to 42. Kidney injury was accessed by the biochemical analyzer, immunofluorescence, and immunohistochemistry. Antibody response was detected by ELISA. T cell clustering and proliferation were detected by flow cytometry. Human kidney 2 (HK2) cells were stimulated in vitro and cytokines were assessed by quantitative real-time PCR. RESULTS: Treatment with sodium acetate, sodium propionate, or sodium butyrate ameliorated the severity of kidney impairment in rats with anti-GBM glomerulonephritis. In the sodium butyrate-treated rats, the urinary protein, serum creatinine, and blood urea nitrogen levels were significantly lower; the percentage of crescent formation in glomeruli was significantly reduced; and the kidneys showed reduced IgG deposition, complement activation, T cell, and macrophage infiltration as well as the level of circulating antibodies against anti-α3(IV)NC1. The treatment of sodium butyrate reduced the α3127-148-specific T cell activation and increased the Treg cells differentiation and the intestinal beneficial bacteria flora. It also alleviated the damage of HK2 cells treated with inflammatory factors and complement. CONCLUSION: Treatment with SCFAs, especially butyrate, alleviated anti-GBM nephritis in rat model, indicating its potential therapeutic effects in clinical usage.

Pathogenesis of Pulmonary Manifestations in ANCA-Associated Vasculitis and Goodpasture Syndrome.

Pulmonary manifestations of vasculitis are associated with significant morbidity and mortality in affected individuals. They result from a complex interplay between immune dysregulation, which leads to vascular inflammation and tissue damage. This review explored the underlying pathogenesis of pulmonary involvement in vasculitis, encompassing various forms such as granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), eosinophilic granulomatosis with polyangiitis (EGPA), and anti-GBM disease. Mechanisms involving ANCA and anti-GBM autoantibodies, neutrophil activation, and neutrophil extracellular trap (NETs) formation are discussed, along with the role of the complement system in inducing pulmonary injury. Furthermore, the impact of genetic predisposition and environmental factors on disease susceptibility and severity was considered, and the current treatment options were presented. Understanding the mechanisms involved in the pathogenesis of pulmonary vasculitis is crucial for developing targeted therapies and improving clinical outcomes in affected individuals.

Enfermedad antimembrana basal glomerular en un paciente trasplantado renal con enfermedad de Alport / Anti glomerular basement membrane disease in a renal transplant patient with Alport syndrome

Se comunica un caso de enfermedad anti membrana basal glomerular (anti MBG) en un paciente com síndrome de Alport que recibió un trasplante de riñón cadavérico. Luego de alcanzar una función renal normal al mês del trasplante, deterioró progresivamente la función a partir del 3er mês y la punción biopsia renal mostró formación de semilunas y depósitos lineales de inmunoglobulinas. El estudio del suero demostró anticuerpos contra la cadena alfa 5 del colágeno tipo IV y recibió tratamiento con plasmaféresis, lográndose estabilización funcional durante un año. Al cabo de dicho lapso una infección respiratoria requirió interrupción de la inmunosupresión y el paciente debió reingresar al programa de hemodiálisis crónica. Se discuten los posibles mecanismos que condicionaron la especificidad de los anticuerpos circulantes en este caso, ya que difiere de la prevalente en la enfermedad anti MBG idiopática, en la que los anticuerpos circulantes están habitualmente dirigidos contra la cadena alfa 3.

Síndrome pulmón-riñón / Lung-kidney syndrome

El síndrome pulmón riñón se caracteriza por hemorragia alveolar severa y glomerulonefritis. Obedece a variadas etiologías, siendo la vasculitis la causa más frecuente. Recientemente se ha establecido que aquellas vasculitis que comprometen a los capilares, alveolares y glomerulares, cursan con síndrome pulmón riñón. Histológicamente se expresan con una inflamación necrotizante de los capilares alveolares y con glomerulonefritis necrotizante y crescéntica en el riñón. El descubrimiento de los ANCA (Antineutrophil Cytoplasmic Antibodies) a permitido mejorar nuestra comprensión del síndrome pulmón riñón. En este artículo se revisa a la luz de los conocimientos actuales, el diagnóstico etiológico de este síndrome. Considerando que las alteraciones histológicas a nivel pulmón son inespecíficas, el diagnóstico etiológico debe realizarse en base a las manifestaciones clinicopatológicas del compromiso extrapulmonar y/o de las alteraciones serológicas características