Clinical characteristics and progression risk factors for patients with monoclonal gammopathy of undetermined significance / 中华血液学杂志

Objective: To analyze the clinical presentation and progression risk factors of patients with monoclonal gammopathy of undetermined significance (MGUS) in China. Methods: We retrospectively assessed the clinical features and disease progression of 1 037 patients with monoclonal gammopathy of undetermined significance between January 2004 and January 2022 at Peking Union Medical College Hospital. Results: A total of 1 037 patients were recruited in the study, including 636 males (63.6%) , with a median age of 58 (18-94) years. The median concentration of serum monoclonal protein was 2.7 (0-29.4) g/L. The monoclonal immunoglobulin type was IgG in 380 patients (59.7%) , IgA in 143 patients (22.5%) , IgM in 103 patients (16.2%) , IgD in 4 patients (0.6%) , and light chain in 6 patients (0.9%) . 171 patients (31.9%) had an abnormal serum-free light chain ratio (sFLCr) . According to the Mayo Clinic model for risk of progression, the proportion of patients in the low-risk, medium-low-risk, medium-high risk, and high-risk groups were 254 (59.5%) , 126 (29.5%) , 43 (10.1%) , and 4 (0.9%) , respectively. With a median follow-up of 47 (1-204) months, 34 of 795 patients (4.3%) had disease progression, and 22 (2.8%) died. The overall progression rate was 1.06 (0.99-1.13) /100 person-years. Patients with non-IgM MGUS have a markedly higher disease progression rate per 100 person-years than IgM-MGUS (2.87/100 person-years vs 0.99/100 person-years, P=0.002) . The disease progression rate per 100 person-years in non-IgM-MGUS patients of Mayo classification low-risk, medium-low risk and medium-high risk groups were 0.32 (0.25-0.39) /100 person-years, 1.82 (1.55-2.09) /100 person-years, and2.71 (1.93-3.49) /100 person-years, which had statistically difference (P=0.005) . Conclusion: In comparison to non-IgM-MGUS, IgM-MGUS has a greater risk of disease progression. The Mayo Clinic progression risk model applies to non-IgM-MGUS patients in China.

Efficacy and safety of daratumumab in the treatment of advanced light chain amyloidosis / 中华血液学杂志

Objective: The study investigated the efficacy and safety of daratumumab in the treatment of cardiac light chain (AL) amyloidosis. Methods: We retrospectively analyzed the clinical characteristics, hematologic response, organ response, long-term survival, and adverse events of 20 patients with newly diagnosed or relapsed/refractory cardiac AL amyloidosis treated with daratumumab in Peking Union Medical College Hospitalo from January 2017 to March 2021. Results: The overall median age of 20 patients was 62 (range, 45-73) yeas, with a male to female ratio of 2.3:1. Nine patients were newly diagnosed, while 11 patients had relapsed or refractory disease. Based on Mayo 2004 cardiac AL staging system, stages Ⅱ and Ⅲ diseases were present in 20 patients respectively. Four patients died during the first cycle of daratumumab, and the remaining 16 patients completed a median of 3 (range, 1-10) cycles of treatment. Overall hematologic response rates were 80% each at 1, 3, and 6 months after treatment initiation, and 45% , 60% , and 60% of the patients achieved at least a very good partial response at 1, 3, and 6 months respectively. The median duration to hematologic response was 13 (range, 6-28) days. At 3, 6, and 12 months, 20% , 30% , and 40% of the patients respectively achieved a cardiac response, and the median days to response was 91 (range, 30-216) days. As of the last follow-up, 9 (45% ) patients died. The 1-month mortality rate of all the patients and stage IIIb patients was 25% and 40% , respectively. The 1-year overall survival rate was 48.4% . Lymphocytopenia was the most common hematological adverse event (above grade 3) . Non-hematological adverse events were mainly infusion-related reactions and infections. Conclusion: Daratumumab could induce deep and rapid hematologic response in newly diagnosed and previously treated cardiac AL amyloidosis patients. However, daratumumab was not effective in preventing the high and early mortality rate in stage Ⅲb patients.

Anti-myelin-associated glycoprotein antibody positive IgM monoclonal gammopathy related peripheral neuropathy: 11 cases and literature review / 中华血液学杂志

Objective: To improve the understanding of rare anti-myelin-associated glycoprotein (MAG) positive IgM monoclonal gammopathy related peripheral neuropathy (IgM-PN) . Methods: Eleven cases of IgM paraproteinemia and anti-MAG antibody positive neuropathy diagnosed since 2014 in Peking Medical Union College Hospital were summarized. The medical records including clinical manifestation, lab results, treatment and prognosis were analyzed. Results: Among the 11 patients (8 male and 3 female) , the median onset age is 63 years old (range from 52 to 77 years old) . The peripheral neuropathy of 9 patients were characterized by distal onset of numbness, 6 patients suffered from muscle weakness. The nerve conduction velocity study indicated that all 11 patients had demyelinating peripheral nerve damage, which was sensory predominant and more severe in lower limbs, 6 of them had secondary axonal damage. Monoclonal IgM gammopathy was identified in all 11 patients, among which 6 were IgM κ, 2 IgG κ and IgM κ bi-clonal, 3 IgM λ. Three patients were diagnosed with Waldenström's macroglobulinaemia. The anti-MAG-IgM antibody was positive in all 11 cases. After diagnosis, 9 patients received combination chemotherapy including rituximab or rituximab treatment alone. The monoclonal IgM level declined significantly in 7 patients. The neuropathy was stable or improved. Conclusions: Anti-MAG antibody positive IgM-PN is a rare M protein related disease. In peripheral neuropathy with undetermined etiology, we suggest to screen M protein and anti-MAG antibody. Chemotherapy including rituximab or rituximab alone is recommended as first-line therapy.

Oral melphalan plus high-dose dexamethasone as first-line therapy for patients with primary light chain amyloidosis / 中华血液学杂志

Objective: To evaluate the response of oral melphalan plus high-dose dexamethasone (MDex) for patients with primary light chain amyloidosis (pAL). Methods: Clinical data, hematological and organ responses, and survival of 76 patients with pAL who had received MDex from January 2009 to July 2017 were retrospectively analyzed. Results: Of 76 patients (47 males and 29 females with the median age of 56 [range, 20-74] years old), 19.70% patients were defined as Mayo 2004 stage 3, involvement of more than or two organs was presented in 65 (85.53%) patients. Among 60 response evaluable patients, overall hematological response was 48.33% with complete response of 20.00% and very good partial response of 20.00%, respectively. The median time to the hematological response was 5 (range, 1-15) months. 36.67% patients achieved organ response. After the median follow up of 23(range, 1-113) months for surviving patients, median progression-free survival (PFS) and overall survival (OS) were 34 and 43 months, respectively. In a three months landmark analysis, the median rates of PFS and OS were 46 and 65 months, respectively. The median OS rates of patients with Mayo 2004 stage 3 and non Mayo 2004 stage 3 were 5 and 65 months (P=0.001), respectively. Conclusions: MDex was an effective treatment for patients with early stage pAL, but was not suitable for those with severe cardiac involvement.

Selection of Biopsy Site for Patients with Systematic Amyloidosis / 中国医学科学院学报

Objective To evaluate the sensitivities of various biopsy methods for the diagnosis of systematic amyloidosis (SA). Methods The clinical data and biopsy results of 194 SA patients who were treated in Peking Union Medical College Hospital from January 2009 to June 2015 were retrospectively analyzed. Results The highest sensitivity was achieved by biopsy of affected organs,with renal biopsy 97.4%,heart biopsy 95.0% and liver biopsy 87.5%. Among non-invasive biopsy methods,tongue biopsy was found to be 75% sensitive,followed by gingiva biopsy at 57%,abdominal fat pad aspiration at 57%,rectum biopsy at 16%,and bone marrow examination at 8%. Combination of tongue and abdominal fat pad biopsy yielded a detection rate of 93.1%. Conclusions Biopsy of the involved organ has the highest sensitivity. However,combination of multiple non-invasive biopsy methods may has sensitivity comparable to organ biopsy and is safer and more convenient.

Light Chain Amyloidosis: an Update for Treatment / 中国实验血液学杂志

Systemic light chain amyloidosis (AL amyloidosis) is the most common type of amyloidosis, in which deposition of misfolded monoclonal light chain secreted by underlying clonal plasma cells leads to organ dysfunction. Tissue biopsy of involved organ is needed to confirm the type of amyloid deposits, thus proper treatment could be applied. Laser microdissection followed by mass spectrometry, performed on formalin-fixed paraffin-embedded specimens, has been proven superior to traditional methods on accurate diagnosis of amyloidosis. Prognosis depends on the extent of cardiac involvement. The Mayo staging system using NT-ProBNP, cardiac troponin-T and free light chain, is the most robust method for risk stratification and treatment guidance. The introduction of autologous stem cell transplantation (auto-ASCT) resulted in long-term survival in responders, while treatment-related toxicity substantially limited the number of eligible candidates. Novel agents, especially bortezomib, thalidomide and lenalidomide hold promise to achieve comparable hematological responses with auto-ASCT, which might play significant role in treatment of recurrent or refractory AL amyloidosis.