The clinical features and outcomes of systemic AL amyloidosis: a cohort of 231 Chinese patients

Abstract

Background: Few data are available on the clinical features and outcomes of Chinese patients with systemic immunoglobulin light-chain (AL) amyloidosis. The aim of this study is to reveal the clinical picture and risk factors of disease progression in a large cohort of Chinese patients with AL amyloidosis.

Methods: Patients in the Jinling Hospital amyloidosis registry from 2003 to 2011 were studied. The clinical and laboratory information were collected from first presentation to death or until the last available clinical follow-up. The patients' survival and renal outcomes were analyzed, and the relationships between the clinical parameters and survival were also assessed.

Results: A total of 231 patients were enrolled in this study, all the patients studied had renal involvement. One hundred and fifty-three (66.2%) were male, and the median age at diagnosis was 56 years. A total of 198 (85.7%) cases had light-chain λ-type. One hundred and forty-seven (63.6%) cases presented as nephrotic syndrome (NS), and 25% of patients had renal insufficiency at diagnosis. Liver involvement and NS appeared to be more common in patients of κ-type amyloidosis, and renal impairment is more severe in κ-type amyloidosis. The median survival time of all patients was 36.3 months, and the 1-, 2-, 3- and 5-year cumulative survival rates were 67, 53, 48 and 35%, respectively. Multivariate COX analysis showed that age, hepatic involvement and heart involvement can significantly influence survival in these patients. The median time that patients remained dialysis free was 50 months. The percentage of patients that remained dialysis free at 1, 2, 3 and 5 years were 78, 69, 62 and 37%, respectively. Multivariate COX analysis showed that serum creatinine and hypotension were the important risk factors of renal failure.

Conclusion: λ-Type is the most dominant type of AL amyloidosis in Chinese patients. The survival of patients with AL amyloidosis is poor. The risk factors included heart and hepatic involvement, hypotension and impairment of renal function. The high serum creatinine level and hypotension at diagnosis are associated with poor renal outcome.

Keywords: AL amyloidosis; clinical characteristic; prognosis; risk factors.

Fig. 1.

The incidence of symptoms at presentation.

Fig. 2.

The positive results of Congo red stain and light-chain stain of renal, rectal mucosa and subcutaneous fat. A, A Congo red stain shows apple green birefringence under polarized light of renal tissue. B, The λ light-chain stain of renal tissue is positive, and the stain for κ light chain is negative. C, A Congo red stain shows apple green birefringence under polarized light of rectal mucosa tissue. D, The κ light-chain stain of rectal mucosa tissue is positive, and the stain for λ light chain is negative. E, A Congo red stain shows apple green birefringence under polarized light of subcutaneous fat. F, The λ light-chain stain of subcutaneous fat is positive, and the stain for κ light chain is negative.

Fig. 3.

Overall survival and renal outcome of all patients and between AL-κ and AL-λ. A, Overall survival of all patients. B, Overall survival between AL-κ and AL-λ. C, The renal outcome of all patients. The median renal survival time is 49 months. D, The renal outcome between AL-κ and AL-λ.

Fig. 4.

Kaplan–Meier curves demonstrating differences in overall survival. A, Survival difference between patients with and without renal insufficiency. B, Survival difference between patients with and without hypotension. C, Survival difference between patients with and without heart involvement. D, Survival difference between patients with and without liver involvement. E, Survival difference between patients with and without special treatment. F, Survival difference between patients with different number of organ involvement.