Serum sulfatide level is associated with severe systemic vasculitis with kidney involvement.

Sulfatides are a type of sulfated glycosphingolipid that are secreted with lipoproteins into the serum. These molecules are involved in the inflammatory pathway of vessels in addition to coagulation and platelet aggregation. Previous studies have proposed that sulfatides play a pivotal role in regulating inflammation-related disorders. Systemic vasculitis (SV) diseases are generally caused by autoimmune diseases and often involve kidney vasculitis, which may lead to rapidly progressive kidney dysfunction and end-stage kidney disease. Our earlier pilot study revealed that the level of serum sulfatides (SSs) was significantly decreased in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV), a representative disease-causing SV with kidney involvement (SVKI), especially in patients exhibiting active crescentic findings on kidney biopsy. To further explore the clinical significance of an association between SS and SVKI, we analyzed and compared the SS level of patients with various SVKI diseases in this retrospective cohort study. Among patients admitted to our hospital between 2008 and 2021, we ultimately enrolled 26 patients with IgA vasculitis (IgAV), 62 patients with AAV, and 10 patients with anti-glomerular basement membrane disease (GBM) as examples of SVKI diseases, as well as 50 patients with IgA nephropathy (IgAN) and 23 donors for living kidney transplantation as controls. The mean ± standard deviation SS level in the donor, IgAN, IgAV, AAV, and GBM groups was 8.26 ± 1.72, 8.01 ± 2.21, 6.01 ± 1.73, 5.37 ± 1.97, and 2.73 ± 0.99 nmol/mL, respectively. Analysis of patients in the SVKI disease group showed that those with the crescentic class kidney biopsy finding exhibited a significantly lower SS level than did those with other class biopsy features. Additionally, the SS level had a higher detection ability for SVKI patients with crescentic class kidney biopsy findings (area under the receiver operating characteristic curve 0.90, 95% confidence interval 0.82-0.99) than did several other predictor candidates. Our results indicate that the SS level is decreased in more severe SVKI diseases and may be associated with active glomerular lesions in SVKI kidney biopsy samples.

Relationship between glomerular number in fresh kidney biopsy samples and light microscopy samples.

BACKGROUND: On-site evaluation of fresh kidney biopsy (FKB) samples at the time of biopsy is useful to verify that adequate specimens are acquired. However, some cases present poor correlation between glomerular number in FKB samples and light microscopy (LM) samples. We examined the usefulness of such on-site evaluation. METHODS: We conducted a retrospective cross-sectional observational study (n = 129) to assess the correlation between glomerular number in FKB samples and LM samples and the associated factors hindering the evaluation. RESULTS: There was a significant positive correlation between glomerular number in FKB samples and LM samples. The median ratio of glomerular number (LM samples/FKB samples) was 0.74. According to this ratio, cases were divided into three groups: reasonable estimation (65 cases), underestimation (32 cases), and overestimation (32 cases). Comparing the reasonable and underestimation groups, significant differences were detected in the extent of interstitial fibrosis and tubular atrophy (IFTA) and interstitial inflammation. Logistic regression analysis demonstrated that IFTA and interstitial inflammation were significantly associated with the underestimation. Moreover, the cortex length of FKB samples correlated with glomerular number in LM samples regardless of tubulointerstitial lesions. CONCLUSIONS: Glomerular number determined during on-site evaluation can be a reference for the actual number of glomeruli in LM samples. Since tubulointerstitial lesions make it difficult to recognize glomeruli in FKB samples, the possibility of underestimation for cases with possibly severe tubulointerstitial lesions should be considered. In such cases, evaluation of cortex length of FKB samples may substitute for evaluating glomeruli on-site.

Comparison of the factors associated with the short-term prognosis between elderly and non-elderly patients with anti-neutrophil cytoplasmic antibody-associated vasculitis: a retrospective observational study.

OBJECTIVES: The difference in factors associated with the prognosis between elderly and non-elderly patients with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) is uncertain. We aimed to elucidate the clinical factors associated with the short-term prognosis (within 6 months from the start of the treatment) and investigate the differences in the associated factors between elderly and non-elderly individuals. METHODS: We performed a dual centre retrospective observational study of patients newly treated with AAV (eosinophilic granulomatous with polyangiitis was excluded). The primary outcome was all-cause death, and the secondary outcome was end-stage renal disease (ESRD) and infectious complications within 6 months after the start of treatment. We analysed factors associated with these outcomes using logistic regression analyses. RESULTS: Of the 79 patients, patients aged ≥75 years were defined as elderly (n=41), whereas those aged <75 years were de¬fined as non-elderly (n=38). In elderly patients, age was significantly associated with all-cause mortality. In the non-elderly patients, the geriatric nutritional risk index was significantly associated with all-cause death. The estimated glomerular filtration rate (eGFR) before the start of treatment was significantly associated with ESRD in elderly and non-elderly patients. In elderly patients, the Birmingham vasculitis score 3, eGFR, methylprednisolone pulse use, and cyclophosphamide use were significantly associated with infectious complications. Factors other than the serum albumin level were not significantly associated with infectious complications in the non-elderly population. CONCLUSIONS: The factors associated with all-cause death and infectious complications differed between elderly and non-elderly patients. Awareness of these differences may contribute to better management of AAV.