99mTc-MDP abdominal scintigraphy in a paediatric case of GI protein loss - A viable and simple alternate to HSA imaging

A nine-month old male child presented with low-grade fever, loose stools and facial puffiness. Clinically patient was otherwise normal except for a firm liver on palpation. The laboratory tests revealed hypoproteinemia (both albumin and globulin) and iron deficiency anemia. Differential diagnosis considered were: 1. Nephrotic syndrome, 2. Cystic fibrosis (in view of recurrent diarrhea and respiratory complaints) 3. Chronic liver disease, in view of firm palpable liver 4. Lastly protein losing enteropathy (PLE). As biochemically patient revealed no positive results, PLE was suspected. For confirmation  99mTc-Methylene diphosponate (MDP) scintigraphy was found to be useful in the setting of non availability of 99mTc-HSA. MDP scan revealed abnormal minimal extravasation of tracer from bowel loops in right lower abdominal quadrant suggesting a diagnosis of PLE. According to the American Gastroenterological Association (AGA) in patients with iron-deficiency anemia who do have GI symptoms, the prevalence of celiac disease is higher and ranges from 10% to 15% which may be a plausible explanation in our patient. The diagnosis of PLE is most commonly based on the determination of fecal alpha-1 antitrypsin clearance. However the localization of gastrointestinal protein (GI) protein loss is possible by scintgraphic techniques alone, as was done in our case using 99mTc-MDP instead of conventionally used 99mTc-HSA.