Clinical features of mucosa-associated lymphoid tissue lymphoma patients with monoclonal gammopathy

Objective To evaluate the incidence and clinical features of monoclonal gammopatly in patients with mucosa-associated lymphoid tissue lymphoma (MALToma). Methods Clinical data of 16 MALToma patients hospitalized from October 2010 to October 2015 who received monoclonal immunoglobulin (M protein) detection were analyzed retrospectively. Results Among 16 MALToma patients, 6 patients (37.5 %) were positive of serum M protein when they were newly diagnosed including 4 males with the median age 56 years (25-82 years), 4 patients were primary gastrointestinal MALToma, 4 patients were in clinical stage Ⅰ-Ⅱ, and 5 patients' international prognostic index (IPI) score ranged from 0 to 2. In 6 cases, there were 4 cases of secretory monoclonal IgM (3 cases of κ light chain, 1 case of λ light chain), and 2 cases of secretory monoclonal IgG (both κ light chain). The plasmacytic differentiation (PCD) could be found in 4 of 6 MALToma patients with M protein positive, but only in 1 of 10 MALToma patients with M protein negative (P = 0.036). M protein levels of 3 patients with M protein positive were reduced obviously when they achieved remission compared with those when they were newly diagnosed, including the levels of 2 cases were decreased to normal range. Conclusions Monoclonal gammopathy may be a common phenomenon in patients with MALToma, which is possibly associated with PCD. The decreased M protein level may be corresponded to a good clinical response. Key words: Mucosa-associated lymphoid tissue lymphoma; Monoclonal immunoglobulin; Clinical features