Comparison of single and repeat centrifugation of blood specimens collected in BD evacuated blood collection tubes containing a clot activator for cardiac troponin I assay on the ACCESS analyzer.

were described previously in a smaller series (3 ). In addition, we discovered a simultaneous course of TH in three sets of twins and two other sibling pairs (neither parent was affected). “Epidemic” incidence and familial occurrence strongly support a relationship of TH with viral, protozoal, or other infections (4, 5). On the other hand, these findings might suggest a genetic predisposition for a unique response to any infection. In our department of clinical biochemistry, ALP isoenzyme electrophoresis has been used for differential diagnosis of TH and organic hyperphosphatasemias. Over the last 8 years, ALP isoenzyme measurements were requested in 562 children under 5 years of age. We detected TH in 187 patients (33%) and hyperphosphatasemia of predominantly bone, intestine, or liver origin in 336 (60%), 21 (4%), and 18 (3%) patients, respectively. To our knowledge, we report the largest series of TH children that has been identified in one hospital. We conclude that TH cannot be regarded as a rare or exceptional syndrome (6 ) and that it belongs among the diagnostic tasks in present-day pediatric chemistry.