Laboratory findings on admission. WBC: white blood cell, RBC: red blood cell, Hb: hemoglobin, Plt: platelet, ESR: erythrocyte sedimentation rate, NAG: N-acetyl-β-D-glucosaminidase, β2MG: β2-microglobulin, BJP: Bence Jones protein, TP: total protein, Alb: albumin, AST: aspartate aminotransferase, ALT: alanine aminotransferase, BUN: blood urea nitrogen, Cr: creatinine, eGFR: estimate glomerular filtration rate, UA: uric acid, CRP: C-reactive protein, ANA: antinuclear antibody, sIL-2R: soluble interleukin-2 receptor, HHV-8: human herpesvirus type 8.