Connective Tissue Diseases With ANCA-Associated Glomerulonephritis Diagnosis Not a Rare Occurrence

There may be an association between antineutrophil cytoplasmic antibody associated glomerulonephritis (ANCA-GN) and connective tissue disease (CTD), according to study results published in the Journal of Clinical Medicine. It was seen that this association was particularly pronounced in women.

Investigators abstracted data from the Maine-Anjou ANCA-associated vasculitides (AAV) registry that included a cohort of patients with AAV admitted to participating hospitals in France. Eligible patients were aged >18 years, had received an ANCA-GN diagnosis between 2000 and 2018, and had at least 6 months of follow-up data. Demographic and clinical data were obtained through medical record review. Renal status at presentation, renal and nonrenal relapse rates, and the frequency of major outcomes in follow-up were assessed. Major outcomes included death, severe infections, cardiovascular events, and thrombotic events. Data from patients with CTD and AAV were compared with data from a control group with AAV alone.

Among 142 eligible patients in the registry, 106 were selected for analysis. CTD was observed at ANCA-GN diagnosis in 16 patients. The most commonly observed CTD diagnoses were rheumatoid arthritis (n=5), systemic sclerosis and/or Sjogren syndrome (n=4), and polymyalgia rheumatica (n=3). Compared with the control group, women were more represented in the CTD group (75%; P =.001). No significant between-group differences were observed in patient age, AAV phenotype distribution, ANCA subtype distribution, organ involvement at AAV diagnosis, and mean Birmingham Vasculitis Activity Score.

While the CTD group vs the control group experienced an elevated rate of nonrenal AAV relapse (25% vs 7.7%, P =.037), renal relapse rates were comparable between groups. Thrombotic events were observed in 31.2% of patients in the CTD group during follow-up, compared with just 10% of patients in the control group (P =.021). However, no between-group differences were observed in the frequency of death, infections, cardiovascular events, and cancers.

Overlap between AAV and CTD was not uncommon in this cohort, with the association more pronounced in women. Despite having a prognosis similar to the control group with AAV alone, patients with AAV and CTD had higher rates of nonrenal relapse and venous thrombotic events. Further study in a prospective cohort is necessary to explore these findings.

Reference

Guibert F, Garnier A-S, Wacrenier S, et al. Patients with ANCA-associated glomerulonephritis and connective tissue diseases: a comparative study from the Maine-Anjou AAV registry. J Clin Med. 2019;8(8):1218.