NUCB1 and lupus nephritis: Further analysis of defined classes revealed an exclusive correlation of lupus nephritis class IV class (n = 12) with elevated antibody levels on the basis of Anti-Nuc, Anti-dsDNA and Anti-dsDNA-NcX ELISA results using Spearman's rank order correlation (rs = 0.192, rs = 0.189, rs = 0.183, respectively; all p < 0.01).