We identified a total of 11 immune- and metabolism-related candidate diagnostic genes (EVI5L, RNASE2, PARP10, TMEM131, TNFRSF1B, BSDC1, ACOT2, SAC3D1, SLA2, P4HB, and PHF1) through various bioinformatics analyses and machine learning algorithms, then provided a nomogram for the diagnosis of MS combined with IPAH. This evidence concerns the gene P4HB and myeloid sarcoma.