Development of a Multivariable Model to Predict the Need for Bone Marrow Sampling in Persons With Monoclonal Gammopathy of Undetermined Significance : A Cohort Study Nested in a Clinical Trial.

BACKGROUND: Monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM) are asymptomatic precursor conditions to multiple myeloma and related disorders. Smoldering multiple myeloma is distinguished from MGUS by 10% or greater bone marrow plasma cells (BMPC) on sampling, has a higher risk for progression, and requires specialist management. OBJECTIVE: To develop a multivariable prediction model that predicts the probability that a person with presumed MGUS has 10% or greater BMPC (SMM or worse by bone marrow criteria) to inform the decision to obtain a bone marrow sample and compare its performance to the Mayo Clinic risk stratification model. DESIGN: iStopMM (Iceland Screens, Treats or Prevents Multiple Myeloma), a prospective population-based screening study of MGUS. (ClinicalTrials.gov: NCT03327597). SETTING: Icelandic population of adults aged 40 years or older. PATIENTS: 1043 persons with IgG, IgA, light-chain, and biclonal MGUS detected by screening and an interpretable bone marrow sample. MEASUREMENTS: Monoclonal gammopathy of undetermined significance isotype; monoclonal protein concentration; free light-chain ratio; and total IgG, IgM, and IgA concentrations were used as predictors. Bone marrow plasma cells were categorized as 0% to 4%, 5% to 9%, 10% to 14%, or 15% or greater. RESULTS: The c-statistic for SMM or worse was 0.85 (95% CI, 0.82 to 0.88), and calibration was excellent (intercept, -0.07; slope, 0.95). At a threshold of 10% predicted risk for SMM or worse, sensitivity was 86%, specificity was 67%, positive predictive value was 32%, and negative predictive value was 96%. Compared with the Mayo Clinic model, the net benefit for the decision to refer for sampling was between 0.13 and 0.30 higher over a range of plausible low-risk thresholds. LIMITATION: The prediction model will require external validation. CONCLUSION: This accurate prediction model for SMM or worse was developed in a population-based cohort of persons with presumed MGUS and may be used to defer bone marrow sampling and referral to hematology. PRIMARY FUNDING SOURCE: International Myeloma Foundation and the European Research Council.

Association Between Autoimmune Diseases and Monoclonal Gammopathy of Undetermined Significance : An Analysis From a Population-Based Screening Study.

BACKGROUND: Monoclonal gammopathy of undetermined significance (MGUS) is a precursor of multiple myeloma (MM) and related conditions. In previous registry-based, retrospective studies, autoimmune diseases have been associated with MGUS. However, these studies were not based on a screened population and are therefore prone to ascertainment bias. OBJECTIVE: To examine whether MGUS is associated with autoimmune diseases. DESIGN: A cross-sectional study within iStopMM (Iceland Screens, Treats, or Prevents MM), a prospective, population-based screening study of MGUS. SETTING: Icelandic population of adults aged 40 years or older. PATIENTS: 75 422 persons screened for MGUS. MEASUREMENTS: Poisson regression for prevalence ratios (PRs) of MGUS among persons with or without an autoimmune disease, adjusted for age and sex. RESULTS: A total of 10 818 participants had an autoimmune disorder, of whom 599 had MGUS (61 with a prior clinical diagnosis and 538 diagnosed at study screening or evaluation). A diagnosis of an autoimmune disease was not associated with MGUS (PR, 1.05 [95% CI, 0.97 to 1.15]). However, autoimmune disease diagnoses were associated with a prior clinical diagnosis of MGUS (PR, 2.11 [CI, 1.64 to 2.70]). LIMITATION: Registry data were used to gather information on autoimmune diseases, and the homogeneity of the Icelandic population may limit the generalizability of these results. CONCLUSION: The study did not find an association between autoimmune disease and MGUS in a systematically screened population. Previous studies not done in systematically screened populations have likely been subject to ascertainment bias. The findings indicate that recommendations to routinely screen patients with autoimmune disease for MGUS may not be warranted. PRIMARY FUNDING SOURCE: The International Myeloma Foundation and the European Research Council.

Red blood cell utilization and transfusion triggers in patients diagnosed with chronic lymphocytic leukaemia in Iceland 2003-2016.

BACKGROUND AND OBJECTIVES: Revised Icelandic guidelines proposed a restrictive haemoglobin (Hb) threshold of 70 g/l for red blood cell (RBC) transfusions in general, but 100 g/l for malignancies/bone marrow suppression. Chronic lymphocytic leukaemia (CLL) is frequently complicated by anaemia. The objective was to investigate RBC transfusion practices in CLL. MATERIALS AND METHODS: This retrospective nation-wide study utilized an Icelandic registry of CLL patients diagnosed between 2003 and 2016. Medical records were reviewed and haemoglobin transfusion triggers compared for two periods: Earlier (2003-2012) and latter (2013-2017). RESULTS: Two hundred and thirteen patients were diagnosed with CLL over the period whereof 77 (36·2%) received RBC transfusion(s). Median time from diagnosis to first transfusion was 2·2 years. Higher age, Rai stage 3/4 at diagnosis (P < 0·05) and chemotherapy (P < 0·001) were associated with increased odds of transfusions. Shorter time to first transfusion correlated with higher age (P < 0·001) and Rai stage (P = 0·02) at diagnosis. The mean Hb trigger was 90·4 and 81·2 in the earlier and latter period respectively (P = 0·01). This difference in Hb triggers was most pronounced in patients without documented bone marrow involvement, or 80·5 g/l compared to 93·5 g/l (P = 0·004). The median time from diagnosis to transfusion was longer in the latter period (2·9 years vs. 1·6 years, P = 0·01). After RBC transfusions the survival decreased significantly (P < 0·001). CONCLUSION: One-third of CLL patients received RBC transfusions but few were heavily transfused. Older age, Rai stage, and chemotherapy predicted RBC use. The Hb transfusion trigger decreased over time while time to first RBC transfusion increased. RBC transfusions predict poor survival.

Homozygous factor V Leiden and double heterozygosity for factor V Leiden and prothrombin mutation.

The most common forms of familial thrombophilia are factor V Leiden (FVL) and prothrombin mutation (PTM). Homozygous FVL and PTM have long been feared conditions thought to cause high rates of morbidity and mortality. To analyse clinical features in patients with homozygous FVL and PTM, as well as patients with double heterozygosity for FVL and PTM. All patients with homozygous FVL, PTM or double heterozygosity in the MATS database of 1465 consecutive unselected patients were analysed regarding age at inclusion venous thromboembolism (VTE), age at first thrombosis, recurrence, clinical course and acquired risk factors. We found 36 patients homozygous for FVL. Patients homozygous for FVL were younger than controls at group level (56 ± 18 vs. 63 ± 17, p < 0.02). Homozygous women were younger than female controls (50 ± 19 vs. 63 ± 18, p < 0.002). No difference was observed when comparing male subjects. Women were younger than men at inclusion thrombosis (50 ± 19 vs. 65 ± 14, p < 0.02) and at first thrombosis (47 ± 19 vs. 64 ± 14, p < 0.01). Deep venous thrombosis (DVT) was seen in 33 patients (92 %), 6 (17 %) had pulmonary embolism (PE) and 3 (8 %) had combined DVT and PE. PE was less frequent in homozygous FVL women compared to female controls (p < 0.03). VTE recurred in 3 subjects during the duration of the study. Odds ratio for VTE in homozygous FVL patients compared to controls was 13.9 (95 % CI 9.9-19.7). We found no subjects with homozygous PTM. Double heterozygosity for FVL and PTM was seen in 12 subjects. There was no difference in age at inclusion VTE between double heterozygotes and controls (59 ± 16 vs. 63 ± 17, ns.). DVT was seen in 92 % at inclusion, 8 % had PE. Mean age at first VTE was 52 ± 17 (27-82). Consecutive homozygous FVL patients had a higher age at first thrombosis than previously described. Homozygous females are affected at an earlier age than homozygous men and female controls. It seems that thrombi in homozygous FVL have a different pattern compared to controls i.e. more prone for thrombosis in the lower extremity. The odds ratio for thrombosis among homozygous FVL seems to be lower than previously described.