Hereditary protein S deficiency associated with rheumatoid arthritis: a case report of pulmonary embolism after total hip arthroplasty

Abstract A 57-year-old woman with RA of 10 years' duration presented with a history of right coxalgia. Three weeks after total hip arthroplasty, the patient developed an acute pulmonary embolism. The results of screening for hypercoagulable states revealed a protein S (PS) deficiency, and all PS values, i.e., total PS antigen, free PS antigen, and PS cofactor, were lower than the normal ranges, showing that the patient had type I PS deficiency. She had no past history of embolism or deep venous thrombosis. The values of three PS-related parameters were also lower than normal in her daughter. The responsible mutation may be located on exon 15 of genomic PS DNA, as indicated by polymerase chain reaction. We therefore diagnosed hereditary PS deficiency.