Abstract 2803

Poster Board II-779

Background.

The rate of asymptomatic amyloidosis (asym-amyloidosis) detected in patients with newly diagnosed multiple myeloma (MM) or smoldering multiple myeloma (SMM) is unknown. This topic is significant because unrecognized AL may be associated with increased mortality may change the patient's management. The objective of the present investigation was to evaluate the number and clinical significance of asym-amyloidosis in MM and SM patients at the time of the diagnostic bone marrow (BM) biopsy for MM.

Materials and Methods.

The study population was selected from the Mayo Clinic Dysproteinemia database and consisted of consecutive patients with an established diagnosis of MM or SMM without recognition of symptomatic AL. Bone marrow biopsies at diagnosis of MM or SMM were retrospectively stained with Congo Red and reviewed by a single pathologist. A patient was considered to have asym-amyloid if Congo Red staining with apple green birefringence was found.

Results.

Biopsies from 144 (M 84, F 59) patients were evaluated: 77 had a diagnosis of MM and 67 of SMM. The median age was 59 (range 26-84) years. No differences were found regarding hemoglobin, platelets, prothrombin time, serum and urine proteins, serum albumin, alkaline phosphate, creatinine and β2-microglobulin among MM and SMM patients. At a median follow-up 76 months (range 0-216), 32% patients were alive, 65% dead and 2.7% lost to follow-up. Immunoglobulin isotypes were as follows: 96/144 (67%) had IgG 23/144 (16%) IgA, 12/144 (8%) had light chain only, 1/77 (1%) had IgD, none had IgM and 12/144 (8%) had biclonal or indeterminate; 84/144 (58%) were κ restricted.

The presence of amyloid was found in only 2 cases (1%, 95% CI – 0.6 to 3.2), 1 in MM and 1 in SMM group. Neither of these patients had or developed signs or symptoms suggestive of organ involvement by amyloid. Among the 142 other patients without amyloid deposition in their index bone marrow, 1 (0.7%, 95% CI -0.6 to 2.0) developed symptomatic AL after 119 months of follow-up. Characteristics of these three patients are shown in table 1.

Conclusions.

We found only 2 cases (1%) of amyloidosis in the 144 cases of MM or SMM. Our estimates are lower than the rates which have been reported by others, perhaps because of our high level of suspicion for amyloid at our Amyloidosis Center. These data do not support the need for searching for asym-amyloidosis in patients with newly diagnosed MM or SMM as long as they have no clinical features of AL.

Table 1.

Characteristics of two patients with detection of amyloid deposits at presentation and one patient without amyloid deposits but subsequent systemic amyloidosis

Clinical/laboratory characteristics at diagnosis of MM or SMMPatients with amyloid deposit at presentation
Patient without amyloid deposit at presentation but subsequent AL
MM patientSMM patient
Months from biopsy to last follow-up 86 88 73 
Age (y) 66 77 51 
Hgb (g/dl) 9.4 13 12.3 
Platelets (n. x 109/l) 328 201 446 
Urine protein (mg/dl) 280 13 
Serum Albumin (g/dl) 2.9 3.6 3,6 
Alkaline Phosphate (U/l) NA 145 152 
Creatinine (mg/dl) 0.8 1.1 0.9 
β2-microglobulin (μg/ml) 2.28 1.56 1.5 
Serum light-chain isotype kappa kappa lambda 
Clinical/laboratory characteristics at diagnosis of MM or SMMPatients with amyloid deposit at presentation
Patient without amyloid deposit at presentation but subsequent AL
MM patientSMM patient
Months from biopsy to last follow-up 86 88 73 
Age (y) 66 77 51 
Hgb (g/dl) 9.4 13 12.3 
Platelets (n. x 109/l) 328 201 446 
Urine protein (mg/dl) 280 13 
Serum Albumin (g/dl) 2.9 3.6 3,6 
Alkaline Phosphate (U/l) NA 145 152 
Creatinine (mg/dl) 0.8 1.1 0.9 
β2-microglobulin (μg/ml) 2.28 1.56 1.5 
Serum light-chain isotype kappa kappa lambda 

NA: Not Available

Disclosures:

Off Label Use: Hydroxyurea use in myelofibrosis. Gertz:celgene: Honoraria; millenium: Honoraria, Membership on an entity's Board of Directors or advisory committees. Witzig:Novartis: Research Funding. Kumar:celgene: Honoraria; millenium: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Author notes

*

Asterisk with author names denotes non-ASH members.

Sign in via your Institution