Bleeding disorder with abnormal wound healing, acid-soluble clots and normal factor XIII.

An unusual bleeding disorder clinically resembling factor XIII deficiency is presented. The only detectable coagulation abnormality was rapid clot dissolution in 1% monochloroacetic acid. This abnormality was ascribed to the sustained increase of a pepsin-like plasma protease which is activated at low pH. Asystematic search for similar phenomena revealed that massive blood transfusion may also enhance plasma-clot solubility in acid, possibly by release of a red cell protease. We conclude that the acid clot solubility test is not a specific indicator of factor XIII deficiency, but this simple assay is recommended for further studies of acid plasma protease activity. The diagnostic relevance and pathophysiologic importance of increased pepsin-like activity in plasma remain to be elucidated.