FAMILIAL AL-AMYLOIDOSIS IN 3 ITALIAN SIBLINGS

Background and Methods. Familial occurrence of immunoglobulin-related (AL) amyloidosis has occasionally been reported. In this work we descr ibe the concomitance of systemic amyloidosis and monoclonal gammopathy (one case of Waldenstrom's macroglobulinemia and two cases without mu ltiple myeloma or related diseases) in three Italian siblings, two mal es and one female. Results and Conclusions. All of them showed a commo n pattern of polyneuropathy to different degrees; two presented a sicc a syndrome and one also suffered from nephropathy. Two of them showed the same HLA typing with the same light chain type (k), but had differ ent presenting symptoms. Polyneuropathy and a history of peptic diseas e in two cases was suggestive of type III familial amyloidotic polyneu ropathy (FAP) occurring in the setting of a familial monoclonal compon ent. However, immunohistochemical studies on different tissue specimen s using anti-apolipoprotein Al and anti-transthyretin antibodies were negative. Further screening of DNA samples for transthyretin (TTR) gen e mutations was also negative. Clinical and laboratory investigations ruled out reactive or senile amyloidosis and immunohistochemical studi es with anti-light chain antibodies on amyloidotic tissue specimens we re positive. As a consequence, this family represents a new case of fa milial AL-amyloidosis.