IGHG3 and interstitial lung disease: The logistic regression analysis showed IgG3 as the only variable associated with the diffusing capacity of the lung for carbon monoxide (DLco) ≤60% of the predicted [OR 9.734 (CI 95%: 1.312–72.221), p < 0.05] and modified Rodnan skin score (mRSS) [OR 1.124 (CI 95%: 1.019–1.240), p < 0.05], anti-topoisomerase I [OR 0.060 (CI 95%: 0.007–0.535), p < 0.05], and IgG3 [OR 14.062 (CI 95%: 1.352–146.229), p < 0.05] as variables associated with radiological interstitial lung disease (ILD).