Marrow Plasma Cell Infiltration Research Articles

International Myeloma Working Group risk stratification model for smoldering multiple myeloma (SMM)

Smoldering multiple myeloma (SMM) is an asymptomatic precursor state of multiple myeloma (MM). Recently, MM was redefined to include biomarkers predicting a high risk of progression from SMM, thus necessitating a redefinition of SMM and its risk stratification. We assembled a large cohort of SMM patients meeting the revised IMWG criteria to develop a new risk stratification system. We included 1996 patients, and using stepwise selection and multivariable analysis, we identified three independent factors predicting progression risk at 2 years: serum M-protein >2 g/dL (HR: 2.1), involved to uninvolved free light-chain ratio >20 (HR: 2.7), and marrow plasma cell infiltration >20% (HR: 2.4). This translates into 3 categories with increasing 2-year progression risk: 6% for low risk (38%; no risk factors, HR: 1); 18% for intermediate risk (33%; 1 factor; HR: 3.0), and 44% for high risk (29%; 2–3 factors). Addition of cytogenetic abnormalities (t(4;14), t(14;16), +1q, and/or del13q) allowed separation into 4 groups (low risk with 0, low intermediate risk with 1, intermediate risk with 2, and high risk with ≥3 risk factors) with 6, 23, 46, and 63% risk of progression in 2 years, respectively. The 2/20/20 risk stratification model can be easily implemented to identify high-risk SMM for clinical research and routine practice and will be widely applicable.

Smoldering multiple myeloma: the role of different scoring systems in identifying high-risk patients in real-life practice

We explore the predictive role of 2014-updated International Myeloma Working Group (IMWG) diagnostic criteria and of some of currently available risk models for progression to symptomatic myeloma when applied in our unselected population of 75 smoldering multiple myeloma (SMM) patients observed between 2000 and 2015. Risk scores including routinely used clinical parameters such as bone marrow plasmacell infiltration rate, immunoparesis, serum monoclonal component (sMC) value, and altered free light chain ratio (FLCr), were clinically useful to identify SMM patients at higher risk of progression. Time to myeloma progression in our ultra-high risk SMM according to IMWG diagnostic update criteria was very short (12.4 months). Our analysis identified as independent reliable predictors of progression altered FLCr as well as increasing plasma cell infiltration which are part of most commonly applied risk models. Waiting for new scoring systems, bone marrow evaluation and complete laboratory screening are still milestones for SMM management.

Pathologic Effects of Vaccinia Virus on Rabbit Bone and Marrow

Although viruses have recently been implicated in the pathogenesis of Paget's disease and Perthes' disease, little information is available regarding bone and marrow response to the presence of a noncarcinogenic virus. Vaccinia virus was introduced into the medullary cavity of the femoral shaft of 30 New Zealand White rabbits, and an appropriate control inoculation was performed. Virus was recovered from the inoculation site in 50% of the animals at intervals to one month after inoculation. Histologic abnormalities were observed in 69% of the test femora; similar abnormalities were not observed in the control femora. These abnormalities consisted of bone and marrow necrosis, lymphocyte and plasma cell infiltration, and new bone formation. Some of the newly formed bone was also necrotic. The latter observation suggests an alternative mechanism for the death of new bone, which, in Perthes' disease, has customarily been attributed to repeated ischemic insults.