Studies of protease and protease inhibitors in familial amyloidotic polyneuropathy

Clinical improvement after liver transplantation for type I familial amyloid polyneuropathy

Long-term results of 13 liver transplantations in patients with a previous diagnosis of type I familial amyloid polyneuropathy (FAP) are presented. The diagnosis of type I FAP was based on the presence of a biochemical marker in the plasma (TTR-Met-30 in 11 patients, TTR-Ala-71 in two). Maximum follow-up is 28 months and the survival rate stands at 11 of 13 patients. Two patients died from sepsis at 2 and 6 months. TTR disappeared from plasma in all cases. Neurological status improved in all eight patients undergoing transplantation more than 6 months previously, although electromyographic studies showed a slight improvement only in the six with follow-up of more than 1 year. All 13 patients showed a hyperdynamic haemodynamic pattern with a high incidence (four patients) of the use of venovenous bypass due to haemodynamic intolerance. Two patients also received transplants by the 'piggy-back' technique. In conclusion, liver transplantation may be useful in the treatment of certain patients with FAP to halt and improve the neurological consequences of the disease.

Studies of protease inhibitors in the sera of patients with amyotrophic lateral sclerosis

Serum levels of 4 protease inhibitors, alpha-1-antitrypsin, C1-inactivator, alpha-2-macroglobulin and antithrombin-III were measured in 11 patients with amyotrophic lateral sclerosis (6 males and 5 females) and a control group without neurologic disease. Our results indicated no significant differences in the level of serum alpha-2-macroglobulin between the 2 groups. We found slight but significantly lower levels of serum antithrombin-III in ALS. The possibility of the participation of proteases or protease inhibitors in the pathogenesis of ALS is discussed.

In vitro degradation of amyloid material by four proteases in tissue of a patient with familial amyloidotic polyneuropathy

The effects of 4 proteolytic enzymes, alpha-chymotrypsin, bromeline, collagenase, and lysozyme on amyloid tissue sections from a patient with familial amyloidotic polyneuropathy (FAP) were evaluated. Degradation of amyloid fibrils was significant with alpha-chymotrypsin, moderate with bromeline and collagenase, and slight with lysozyme. All of these proteases except collagenase are used as oral mucolytics in humans. The possibility of their clinical usefulness in the treatment or prevention of the development of FAP is discussed.