紫斑病性腎炎

Immunoglobulin A vasculitis (IgAV), formerly known as Henoch-Schönlein purpura, is a complex immune-mediated vasculitis characterized by the involvement of small blood vessels in various organ systems. We describe the case of a 14-year-old girl who developed a non-typical manifestation of vasculitis with notable rhinological features. The patient presented with a vasculitis-type rash on the hands and lower extremities bilaterally and arthralgia, while she also complained about intense nasal congestion. The laboratory results were atypical for a specific disorder, and the skin and nasal mucosa biopsies were not diagnostic. Since the patient presented with microscopic hematuria, she underwent a kidney biopsy that confirmed the diagnosis of IgAV with nephritis. The patient was maintained on long-term therapy with corticosteroids, azathioprine, and hydroxychloroquine and showed improvement in symptoms. The aim of this case report is to highlight the atypical presentation of IgAV, particularly its rhinologic manifestations, which are infrequently reported in the literature. In addition, this report emphasizes the importance of long-term follow-up in such patients, as the diagnosis can be challenging.

AIMS: IgA vasculitis with nephritis (IgAVN), a severe renal manifestation of IgA vasculitis, is rare in adults and associated with high morbidity. Current therapies are suboptimal, highlighting the need for novel approaches. This case study evaluates telitacicept, a dual BAFF/APRIL inhibitor, in a high-risk adult IgAVN patient. MATERIALS AND METHODS: A 45-year-old male with biopsy-confirmed IgAVN, progressive renal impairment (estimated glomerular filtration rate (eGFR): 44 mL/min/1.73m2), and significant proteinuria (1.08 g/day) was treated with weekly subcutaneous telitacicept (160 mg) and oral prednisone. Clinical outcomes were assessed over 6 months. RESULTS: After 6 months, the patient showed rapid and sustained improvement: proteinuria decreased by 78.7% (from 1.08 to 0.23 g/day), and renal function stabilized (serum creatinine: 90.9 μmol/L; eGFR preserved). Prednisone was tapered and discontinued without relapse, demonstrating telitacicept's steroid-sparing effect. No treatment-related adverse events occurred. CONCLUSION: Telitacicept appeared to reduced proteinuria, stabilized renal function, and allowed corticosteroid withdrawal in refractory IgAVN. These findings suggest dual BAFF/APRIL inhibition as a promising strategy for IgA-mediated diseases, warranting further studies to confirm its role in IgAVN.

BACKGROUND: Immunoglobulin A vasculitis with nephritis (IgAVN) is the most common form of secondary glomerulonephritis in children. Some individuals have acute kidney disease (AKD) early on in their illness. The purpose of this study was to examine the prognosis and clinicopathological characteristics of children with IgAVN complicated by AKD. METHODS: Five medical centers in China provided data on pediatric patients with biopsy-proven IgAVN. The patients were divided into two groups: AKD group and non-AKD group, depending on whether AKD was present at disease onset. Clinical manifestations, laboratory findings, pathological characteristics, and prognostic outcomes were compared between the two groups. RESULTS: Among 1862 children with IgAVN, 213 (11.44%) presented with AKD. Compared to children in the non-AKD group, children in the AKD group had more severe clinical and pathological findings. Kaplan-Meier analysis revealed statistically significant differences in kidney survival among the three stages of AKD (χ² = 15.68, P < 0.0001), and showed that kidney survival in the AKD group was significantly lower than that in the non-AKD group (χ² = 14.75, P < 0.0001) over a median follow-up of 66 months. AKD was identified as an independent risk factor for progression to chronic kidney disease stage 5 (CKD 5) in both short-term (6 months) and long-term (five- and ten-year) follow-ups. CONCLUSIONS: The clinicopathological and pathological features are much more severe in IgAVN children with AKD. AKD is a significant risk factor for unfavorable short- and long-term outcomes in pediatric IgAVN.

Autoantibody-driven autoimmune diseases, such as systemic lupus erythematosus, frequently affect organs such as the kidney. The differentiation and function of pathogenic immune cells that drive these diseases are in part controlled by their metabolic programming. For diseases that affect the kidney, the response of kidney cells to immune-mediated injury is also in part controlled by metabolic changes. Immune cells that promote the production of autoantibodies and/or infiltrate the kidney in lupus nephritis are sustained by enhanced glycolysis and mitochondrial oxidation. These metabolic processes are also enhanced in the mesangial and glomerular endothelial cells of patients with lupus nephritis and animal models of lupus nephritis, which may contribute to tissue injury. Similar alterations in metabolic processes might be involved in other autoimmune diseases that affect the kidney, including IgA nephropathy and ANCA-associated vasculitis. Insights into metabolic changes that occur in the context of autoimmune-mediated kidney diseases might have therapeutic implications. Despite the complexity of metabolic alterations presented by specific immune and renal cells in these autoimmune diseases, targeting of glycolysis, mitochondrial oxidation or iron metabolism could offer novel opportunities to enhance existing treatments for autoimmune-mediated kidney injury.

BACKGROUND: CD163 is a surface marker expressed by M2c macrophages. This study aims to evaluate the level of urinary soluble CD163 (u-sCD163) in children with IgA vasculitis with nephritis (IgAVN) and its potential diagnostic value. METHODS: U-sCD163 was analyzed in 73 children with IgAVN who underwent a kidney biopsy, 37 children with IgA nephropathy and 50 normal controls. CD163 expression was analyzed by immunohistochemistry. Correlation analyses and inter-group comparison were performed to assess the association between u-sCD163 levels and clinicopathological features of IgAVN. The comparison of u-sCD163 levels before and after treatment was conducted. RESULTS: The level of u-sCD163 was significantly higher in children with IgAVN than healthy controls. Compared with grade II IgAVN subjects, u-sCD163 level was significantly elevated in grade III-IV subjects. There was no difference in u-sCD163 level between IgAVN and IgA nephropathy groups. There was no difference in serum CD163 level among different groups. In the IgAVN group, abundant CD163-positive cells were observed in glomeruli showing endocapillary proliferation, especially in areas of thrombosis and fibrinoid necrosis. In contrast, CD163-positive cells were scarce within cellular crescents, but increased in fibrocellular crescents. Levels of u-sCD163 showed a significant positive correlation with proportions of endocapillary proliferation, and moderately correlated with proteinuria, CD163 score of glomerular area, and weakly correlated with proportions of cellular crescents, D-dimer and fibrin degradation products (FDP). The level of u-sCD163 decreased significantly after treatment. CONCLUSIONS: U-sCD163 emerges as a promising marker associated with endocapillary proliferation and coagulation in pediatric patients with IgAVN.