Depth of organ response in AL amyloidosis is associated with improved survival: grading the organ response criteria

Organ recovery following anti-plasma cell therapy is associated with improved outcome in patients with AL amyloidosis. Current organ response criteria do not consider the depth of response. Newly diagnosed AL amyloidosis patients who had involvement of at least one evaluable organ and documentation of organ response were included. Cardiac response was seen in 182 patients. Time to cardiac response was 9.4 months. Renal response was seen in 278 patients, at a median time to response of 6 months. Hepatic response was seen in 70 patients, with a median time to response of 6.1 months. In all organs, the deeper the organ response achieved, the longer the survival. This led to four organ response criteria: complete organ response (nadir NT-proBNP ≤400 pg/mL; nadir proteinuria ≤200 mg per 24 h; nadir alkaline phosphatase ≤×2 lower limit of normal); very good partial organ response (>60% reduction in parameter not meeting complete organ response definition); partial organ response (31–60% reduction in parameter); and non-responder (≤30% reduction in organ response parameter). Cardiac and renal progression were associated with baseline organ impairment and inversely associated with the depth of organ response. Grading the depth of organ response provides additional valuable prognostic information for newly diagnosed AL amyloidosis patients.