1. Dorothy M (Adcock) Funk, M.D.[⇑][1] 1. Esoterix Coagulation, 8490 Upland Drive, Ste.100, Englewood, CO 80112 2. Dennis Casciato, M.D. 1. David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-1732 1. Address for Correspondence: Dorothy M (Adcock) Funk, M.D., Esoterix Coagulation, 8490 Upland Drive, Ste.100, Englewood, CO 80112, Office: 720 568 4328, Fax: 720 568 4314, Dot.Adcock{at}Esoterix.com PATIENT 52-year old Caucasian female who initially presented with lower abdominal discomfort. Evaluation included a urinalysis which was 4+ positive for protein. A 24-hour urine demonstrated 7.7 gm of protein/24 hours. Prior to undergoing a renal biopsy, a prothrombin time (PT) and activated partial thromboplastin time (aPTT) were ordered and the patient was noted to have an elevated PT of 22.4 seconds (normal range 10.0 – 13.0 sec) with an INR of 2.12 and a normal aPTT. CLINICAL HISTORY The clinical history is otherwise not remarkable. She underwent transabdominal hysterectomy and bilateral salpingoophrectomy and cystocele repair 6 years previously without any bleeding complications or report of abnormal laboratory screening assays. She had undergone tooth extractions without bleeding and did not suffer menorrhagia, epistaxis or easy bruisability. FAMILY HISTORY No family history of bleeding dyscrasias. MEDICATIONS None PHYSICAL EXAMINATION Unremarkable with the exception of 2+ pitting edema of the lower extremities INITIAL WORK-UP PT mixing studies showed evidence of correction into the reference range consistent with a factor deficiency. FX activity repeated on a new plasma sample at another laboratory yielded a result of 32% (reference interval 65–135%). DIFFERENTIAL DIAGNOSIS 1. Acquired FX deficiency: An acquired factor X deficiency is the most likely diagnosis as the patient does not have a history of bleeding and was not known to have abnormal APTT and/or PT in the past. Isolated acquired FX deficiency raises the possibility of amyloidosis which is most commonly a complication of an underlying plasma cell dyscrasia. Factor X activity could… DIFFERENTIAL DIAGNOSIS ABBREVIATIONS: PT - prothrombin time, aPTT – activated partial thromboplastin time, INR – international normalized ratio. [1]: #corresp-1