Evaluation of indicators of cobalamin deficiency defined as cobalamin-induced reduction in increased serum methylmalonic acid.

BACKGROUND: Early detection of cobalamin deficiency is clinically important, and there is evidence that such deficiency occurs more frequently than previously anticipated. However, serum cobalamin and other commonly used tests have limited ability to diagnose a deficiency state. METHODS: We investigated the ability of hematological variables, serum cobalamin, plasma total homocysteine (tHcy), serum and erythrocyte folate, gastroscopy, age, and gender to predict cobalamin deficiency. Patients (n = 196; age range, 17-87 years) who had been referred from general practice for determination of serum cobalamin were studied. Cobalamin deficiency was defined as serum methylmalonic acid (MMA) >0.26 micromol/L with at least 50% reduction after cobalamin supplementation. ROC and logistic regression analyses were used. RESULTS: Serum cobalamin and tHcy were the best predictors, with areas under the ROC curve (SE) of 0. 810 (0.034) and 0.768 (0.037), respectively, but age, intrinsic factor antibodies, and gastroscopy gave additional information. CONCLUSIONS: When cobalamin deficiency is suspected in general practice, serum cobalamin should be the first diagnostic test, and the result should be interpreted in relation to the age of the patient. When a definite diagnosis cannot be reached, MMA and tHcy determination will provide additional discriminative information, but MMA, being more specific, is preferable for assessment of cobalamin status.

[Familial hypocalciuric hypercalcemia]. / Familiaer hypokalsurisk hyperkalsemi.

Familial hypocalcuric hypercalcemia is a condition that is often incorrectly diagnosed and treated. We studied a family with seven members who had familial hypocalcuric hypercalcemia. In four of the family members it was difficult to make the diagnosis. A correct diagnosis was made in the other three on the basis of known family history. Subtotal parathyroidectomi was carried out on three of the family. After operation, two of these experienced a relapse, and one became permanently hypocalcemic.

Bone scanning of fractures of the scaphoid.

The value of isotope scanning in patients with clinical signs of fracture of the carpal scaphoid bone and negative or non-diagnostic initial radiographs was examined. 30 patients were examined using both radiography and isotope scanning. A normal scan excludes a fracture. Increased activity localized to the scaphoid bone indicates a fracture. 9 patients had fracture of the scaphoid evident on bone scans within 2 weeks of the injury. It took 2-6 weeks before these fractures showed up on radiographs.