Endocrine Abstracts

A 52-year-old postmenopausal woman was referred to endocrinology clinic for evaluation of persistent isolated elevation of alkaline phosphatase during routine check-up. Her past medical history was notable for hypothyroidism and vitamin D deficiency. She denied history of fractures or kidney stone. She denied using over the counter supplement, alcohol, smoking or drug use. Family history was suggestive of autoimmune disease, including celiac disease, type 1 diabetes, rheumatoid arthritis, and thyroid disease. Her physical examination was completely unremarkable. Initial laboratory investigation revealed elevated alkaline phosphatase (ALP) of 159 U/L (reference range: 40–150), with normal transaminase level. Subsequent labs were rechecked with further elevation of ALP to 177 U/L at 6 months and 212 U/L at 1-year follow-up. Additional labs revealed mild hypocalcemia with corrected calcium of 8.4, normal TSH, GGT, hepatitis B and C panel, ESR and CRP. Liver ultrasound revealed a 1.2 cm benign appearing hemangioma and no apparent culprit for abnormal enzymes. Further evaluation of persistent elevation of ALP revealed a fractionated bone alkaline phosphatase of 42.2 μg/L (reference range: 7–22.4 for postmenopausal woman). Subsequent nuclear bone scan demonstrated linear tram-like increased uptake in the bilateral tibia without focal areas of abnormal radiotracer uptake within the skeleton. Because of the patient’s and family history of autoimmune disease as well bone scan finding, further work-up revealed a positive serum transglutaminase IgA indicated celiac disease. She was ultimately started on gluten-free diet with complete normalization of ALP. Periostosis is a radiographic hallmark of hypertrophic osteoarthropathy (HOA) which manifests along the shafts of tubular bones. HOA can also present as digital clubbing or synovial effusions. It is characterized by abnormal skin proliferation at the distal parts of the extremities as well as periosteal proliferation of the long bones. HOA is commonly associated with pulmonary disease but it could also be related to a variety of conditions involving different organ systems such as infection, inflammatory bowel disease, thyroid disease or hematologic malignancy. Herein, this case highlights HOA as a rare presentation of celiac disease.