In patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) related to glomerulonephritis, a novel predictor of renal prognosis has been described, according to findings from a retrospective study published in the European Journal of Medical Research.
AAV has been officially defined as “a group of pauci-immune small-vessel vasculitides closely related to ANCA and specific for myeloperoxidase (MPO) or proteinase 3 (PR3), with inflammation and necrosis of the small vessel walls as the main manifestations.” Among individuals with AAV, more than 75% report renal involvement.
Increasing evidence has demonstrated that the renal risk score (RRS) plays a key role in predicting renal prognosis in patients with AAV-associated glomerulonephritis. The RRS is based on the following 3 parameters:
- Estimated glomerular filtration rate,
- Percentage of normal glomeruli, and
- Rate of renal tubular/interstitial fibrosis.
Read more about antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis
In individuals with AAV-related glomerulonephritis, timely initiation of evaluation and treatment is key for the prevention of progression to end-stage renal disease (ESRD). The researchers sought to assess the predictive value of the RRS, the Birmingham Vasculitis Activity Score (BVAS), and the Renal Vascular Lesions (RVLs) score for renal prognosis in this patient population.
The primary study endpoint was progression to ESRD over time (which was censored for death). ESRD was defined as “the need for long-term renal replacement therapy or renal transplantation.”
Ninety-four individuals who had undergone renal biopsy and were diagnosed with AAV-associated glomerulonephritis between April 2014 and May 2021 at the First Affiliated Hospital of Zhengzhou University, in China, were enrolled in the study. The average participant age at renal biopsy was 60.0 years (range, 49.0-67.0 years). Overall, 48 patients were female and 46 were male.
MPO-ANCA and PR3-ANCA were positive in 87.2% and 12.8% of patients, respectively. Participants’ median estimated glomerular filtration rate was 17.5 mL/min/1.73 m2. In all, 18.1% (17 of 94) of the patients underwent dialysis for their initial treatment. The median follow-up period was 36 months, and 38 of the participants progressed to ESRD.
The groups were classified according to RRS as follows:
- 38.3% (36 of 94): low RRS group
- 45.7% (43 of 94): medium RRS group
- 16.0% (15 of 94): high RRS group
In a similar fashion, the RVLs score was divided into the following 4 groups:
- 13.8% (13 of 94): without RVLs
- 41.5% (39 of 94): mild RVLs
- 30.9% (29 of 94): moderate RVLs
- 13.8% (13 of 94): high RVLs
Among the 3 RRS subgroups, renal survival in the high RRS group was significantly worse than in the low RRS (P <.001) and medium RRS (P =.004) group. Further, renal survival was significantly worse in the medium RRS group than in the low RRS group (P <.001).
Read more about AAV comorbidities
Renal survival in the group with severe RVLs was significantly worse than in the group without RVLs (P <.001), the group with mild RVLs (P <.001), and the group with moderate RVLs (P =.001).
Receiver operating characteristic analysis showed that the area under the curve of RRS, BVAS, RVLs score, RVLs score + RRS (RR), and RVLs score + BVAS (RRB) were 0.865, 0.624, 0.783, 0.910, and 0.942, respectively. According to simplicity and validity, RR was chosen as the best predictor of renal prognosis.
“It is suggested that the RR model should be used in clinical practice for the assessment of renal prognosis in patients with AAV-associated glomerulonephritis,” the researchers concluded.
Reference
Wang R, Zhang X, Wang X, et al. Evaluation of three scoring systems for predicting renal prognosis in antineutrophil cytoplasmic antibody-associated glomerulonephritis. Eur J Med Res. Published online May 9, 2023. doi:10.1186/s40001-023-01113-7
