AL amyloidosis associated with IgM paraproteinemia: clinical profile and treatment outcome.
AL amyloidosis associated with immunoglobulin M (IgM) paraproteinemia is rare. We report 103 consecutive such patients evaluated at the National Amyloidosis Centre (London, United Kingdom) between 1988 and 2006. Renal, cardiac, and lymph node amyloid was present in 53%, 35%, and 21% of patients, respectively, at presentation and 2 or more organs were involved in 54%. Seventy-three percent had an abnormal bone marrow infiltrate (lymphoid in 87%). The median IgM paraprotein was 8 g/L and serum free light chain (FLC) ratio was abnormal in 77 (88%) of 87. The abnormal FLC component was more than 100 mg/L in only 31% cases. Thirty-two percent achieved a partial hematologic response to treatment with no complete responders, and there appeared to be a greater response to combination regimens than single-agent oral alkylators (59% vs 20%, respectively; P = .003). Four achieved amyloidotic organ responses; organ function remained stable in 68%. None with lymph node involvement showed nodal improvement. Median overall survival was 49 months. AL amyloidosis with IgM paraproteinemia represents a distinctive subset of patients with AL amyloidosis who have a wider variety of underlying clonal disorders (often lymphoid) than AL in general, have low-level FLC abnormality, and should be treated with appropriately tailored chemotherapeutic regimens for the underlying clonal disorder.
Wechalekar
Ashutosh D
AD
National Amyloidosis Centre, Centre for Amyloidosis & Acute Phase Proteins, Department of Medicine (Hampstead Campus), Royal Free and University College Medical School, London, United Kingdom. a.wechalekar@medsch.ucl.ac.uk
Lachmann
Helen J
HJ
Goodman
Hugh J B
HJ
Bradwell
Arthur
A
Hawkins
Philip N
PN
Gillmore
Julian D
JD
D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000477:Alkylating Agents / Q000008:administration & dosage; D000686:Amyloidosis / Q000097:blood / Q000150:complications / Q000188:drug therapy / Q000401:mortality*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009928:Organ Specificity; D010265:Paraproteinemias / Q000097:blood / Q000150:complications / Q000188:drug therapy / Q000401:mortality*; D012189:Retrospective Studies; D015996:Survival Rate; D006113:United Kingdom
D000477:Alkylating Agents; D007147:Immunoglobulin Light Chains; D007075:Immunoglobulin M