Immunoparesis in newly diagnosed AL amyloidosis is a marker for response and survival.

Immunoparesis is an adverse prognostic marker in plasma cell proliferative disorders. Its impact in AL amyloidosis has not been explored in depth. Newly diagnosed AL amyloidosis patients (n=998) were evaluated for immunoparesis by two methods. The first method was qualitative, considering the number of suppressed uninvolved immunoglobulins below the lower limit of normal (LLN) (none, partial, all). The second method was quantitative, assessing the average relative difference (ARD) of the uninvolved immunoglobulins from the LLN. Patients with suppression of all the uninvolved immunoglobulins were less likely to achieve very good partial response (VGPR) or better to first-line treatment (44%) compared with patients with partial suppression (68%) or preserved uninvolved immunoglobulins (64%; P<0.0001). In addition, patients with suppression of all the uninvolved immunoglobulins had a shorter survival compared with the respective comparators (median 18 vs 54 vs 52 months; P<0.0001). In the quantitative method, patients with a negative ARD were less likely to achieve VGPR or better (48%) and had a shorter survival (median 24 months) compared with patients with a positive ARD (69%, 57 months, respectively; P<0.0001). In a multivariate analysis for survival, both assessment methods retained an independent impact. Significant immunoparesis has a negative impact on response and survival in newly diagnosed AL amyloidosis.