Development of biopsy-proven giant cell arteritis in a patient with dermatomyositis on methotrexate: comment on the article by Monti et al.

OBJECTIVES Tubulointerstitial damage in lupus nephritis (LN) is an important predictor of renal prognosis. Here, we investigated the factors associated with aggravation of tubulointerstitial damage in patients with LN. METHODS Patients with LN, who underwent repeated renal biopsy due to treatment failure at a tertiary referral hospital between 1997 and 2017 were identified. Clinicopathologic and laboratory data were collected. Aggravation of tubulointerstitial damage (tubular atrophy and/or interstitial fibrosis) was defined as progression of severity from none-to-mild to moderate-to-severe. Factors associated with aggravation of tubulointerstitial damage were evaluated using logistic regression analysis. RESULTS A total of 52 LN patients were included for analysis. Aggravation of tubulointerstitial damage at the second renal biopsy was observed in 19 (36.5%) patients. In multivariable logistic regression analysis, use of hydroxychloroquine (adjusted OR 0.215, 95% CI 0.049-0.941, p=0.041) was inversely associated with aggravation of tubulointerstitial damage, and higher renal component of systemic lupus erythematosus disease activity index (SLEDAI) at first biopsy (adjusted OR 1.331, 95% CI 1.083-1.636, p=0.007) was associated with aggravation of tubulointerstitial damage. In terms of use of HCQ, both length of treatment with HCQ (adjusted OR 0.974, 95% CI 0.951-0.998, p=0.036) and cumulative dose of HCQ (log transferred value) (adjusted OR 0.485, 95% CI 0.262-0.896, p=0.020) were inversely associated with aggravation of tubulointerstitial damage. CONCLUSIONS Use of hydroxychloroquine was associated with lower risk of aggravation in tubulointerstitial damage, and higher renal component of SLEDAI at first renal biopsy was associated with higher risk of aggravation in tubulointerstitial damage.