NPPB and mixed connective tissue disease: Laboratory analysis indicated that MCTD patients had lower platelet (PLT) counts (221.78 ± 71.88 vs. 253.96 ± 80.13, p = 0.01) and higher troponin T (TNT) (31.32 ± 74.85 vs.12.83 ± 16.30, p = 0.04) and brain natriuretic peptide (BNP) levels (193.35 ± 351.59 vs. 57.37 ± 53.68, p = 0.04) compared to patients with SSc.