PTPRC and systemic lupus erythematosus: Joint manifestations appeared to be protective (OR < 1, p < 0.05), whereas elevated SLEDAI-2000, anti-dsDNA antibodies, ESR, WBC, CD45+ lymphocytes, CD3+CD8+ T cells, PD-1+CD3+ T cells, PD-1+CD4+ T cells, PD-1+CD8+ T cells, 24h-UTP, CysC, as well as cutaneous involvement and edema, were all identified as risk factors for LN in SLE patients (OR > 1, p < 0.05).