Clinical manifestations at diagnosis in Japanese patients with systemic AL amyloidosis: a retrospective study of 202 cases with a special attention to uncommon symptoms.

Objective To retrospectively investigate the clinical manifestations at diagnosis in Japanese patients with systemic AL amyloidosis. Methods We reviewed the medical records of 230 Japanese patients who had visited our hospital and been diagnosed with AL amyloidosis, and abstracted those with the systemic type. The clinical data at diagnosis of systemic AL amyloidosis, including laboratory and imaging findings, were analyzed. Results Two hundred and two patients (mean, 58.7±9.5 years) were enrolled in this study. Immunofixation or immunoelectrophoresis was performed in 173 patients, 144 of whom were positive for M-protein in the serum and/or urine (κ:λ=30:114). The primary clinical manifestations at diagnosis were proteinuria and/or renal dysfunction (54.0%), congestive heart failure (24.8%), peripheral neuropathy (10.4%), hepatomegaly (7.9%) and arrhythmia (5.0%). The remaining patients developed unusual manifestations, such as solitary tumor, lymphadenopathy, gastrointestinal bleeding, intestinal pseudoobstruction, hemorrhagic tendencies and polyarthralgia. Dilatation of the intestine with marked thickening of the gastrointestinal wall on computed tomography and multiple nodular lesions with associated mucosal friability on endoscopy are characteristic findings of systemic AL amyloidosis. Conclusion The clinical pictures of Japanese patients with systemic AL amyloidosis are similar to those previously reported from the US and European nations; however, some patients with this disease develop uncommon symptoms. Conducting laboratory and histological examinations for systemic AL amyloidosis is necessary when making a differential diagnosis of these symptoms.