[Clinical Characteristics and Survival Analysis of Patients with IgD Multiple Myeloma]

To explore the clinical features, prognosis and survival of patients with IgD multiple myeloma (MM).

The clinical data of 20 patients with IgD MM was analyzed retrospectively. The prognostic factors and survival analysis was carried out. We summarized their clinical characteristics. The survival analysis was carried out by Kaplan-Meier method, and the prognostic factor were analyzed by using log-rank test for single factor analysis of observation index. Variables of P<0.15 in single factor analysis were enrolled in multifactor cox regression analysis.

IgD MM patients accounted for 4.3% of all MM patients in the same period, among which 80% were male, the median age of patients was 57.5(35-77) years old, 90% of the patients belongs to λ light chain type. At the time of diagnosis, 18 patients (90%) were in DS-Ⅲ stages, while 10 patients were in ISS-Ⅲ stage. The first clinical manifestations were fatigue, bone pain, kidney function impairment, anemia (Hb<100 g/L) in 14 cases (70%), 12 cases (60%) with osteolytic bone destruction≥3, combined with renal impairment in 8 cases (40%), and elevated blood calcium in 11 cases (51.4%). In only 5 patients the ratio of albumin to globntin was inverted, hypoalbuminemia accounted for 40%, and globulin increase accounted for only 15%. FISH results showed that the positive rate of 1q21 amplification (50%) was the highest, and it was easy to occur at the same time as other cytogenetic abnormalities. Extramedullary infiltration occurred in 4 cases (20%). The analysis of prognostic factors showed that only the increase of lactate dehydrogenase (LDH) level was an independent poor prognostic factor for IgD MM patients. Extramedullary infiltration and various cytogenetic abnormalities were found in 2 IgD MM patients with primary drug resistance, suggesting that extramedullary infiltration and various cytogenetic abnormalities may be prognostic factors, but the difference was not statistically significant, Which maybe related to the small sample size. All 20 patients were treated with bortezomib-containing regimen, of which 19 patients were evaluated, 17 patients (89.4%) showed effective, including CR+VGPR (52.6%), PR (31.5%), MR (5.3%), 2 patients primary drug resistance. The median PFS and OS was 9.5 and 10.5 months, respectively.

IgD MM is a rare and invasive disease. Increased LDH is an independent prognostic factor. Bortizomib-containing regimen can improve the prognosis of IgD MM patients.