Citations

Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant plasma-cell proliferative disorder associated with a life-long risk of progression to multiple myeloma (MM). It is not known whether MM is always preceded by a premalignant asymptomatic MGUS stage. Among 77 469 healthy adults enrolled in the nationwide population-based prospective Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, we identified 71 subjects who developed MM during the course of the study in whom serially collected (up to 6) prediagnostic serum samples obtained 2 to 9.8 years prior to MM diagnosis were available. Using assays for monoclonal (M)–proteins (electrophoresis/immunofixation) and kappa-lambda free light chains (FLCs), we determined longitudinally the prevalence of MGUS and characterized patterns of monoclonal immunoglobulin abnormalities prior to MM diagnosis. MGUS was present in 100.0% (87.2%-100.0%), 98.3% (90.8%-100.0%), 97.9% (88.9%-100.0%), 94.6% (81.8%-99.3%), 100.0% (86.3%-100.0%), 93.3% (68.1%-99.8%), and 82.4% (56.6%-96.2%) at 2, 3, 4, 5, 6, 7, and 8+ years prior to MM diagnosis, respectively. In approximately half the study population, the M-protein concentration and involved FLC-ratio levels showed a yearly increase prior to MM diagnosis. In the present study, an asymptomatic MGUS stage consistently preceded MM. Novel molecular markers are needed to better predict progression to MM in patients with MGUS.

Abstract We examined whether monoclonal gammopathy of undetermined significance (MGUS) is increased in first-degree relatives of multiple myeloma (MM) or MGUS patients. Probands were recruited from a population-based prevalence study (MGUS) and the Mayo Clinic (MM). Serum samples were collected from first-degree relatives older than 40 years and subjected to electrophoresis and immunofixation. The prevalence of MGUS in relatives was compared with population-based rates. Nine-hundred eleven relatives of 232 MM and 97 MGUS probands were studied. By electrophoresis, MGUS was detected in 55 (6%) relatives, and immunofixation identified 28 additional relatives for an age- and sex-adjusted prevalence of 8.1% (95% CI, 6.3 to 9.8). The prevalence of MGUS in relatives increased with age (1.9%, 6.9%, 11.6%, 14.6%, 21.0% for ages 40-49, 50-59, 60-69, 70-79, ≥ 80 years, respectively; P < .001). Using similar MGUS detection methods, there was a higher risk of MGUS in relatives (age-adjusted risk ratio [RR], 2.6; 95% CI, 1.9 to 3.4) compared with the reference population. The increased risk was seen among relatives of MM (RR, 2.0; 95% CI, 1.4 to 2.8) and MGUS probands (RR, 3.3; 95% CI, 2.1 to 4.8). The increased risk of MGUS in first-degree relatives of MGUS or MM patients implies shared environment and/or genetics.

Abstract Therapeutic decision-making in primary myelofibrosis (PMF) is becoming more challenging because of the increasing use of allogeneic stem cell transplantation and new investigational drugs. To enhance this process by developing a highly discriminative prognostic system, 1054 patients consecutively diagnosed with PMF at 7 centers were studied. Overall median survival was 69 months (95% confidence interval [CI]: 61-76). Multivariate analysis of parameters obtained at disease diagnosis identified age greater than 65 years, presence of constitutional symptoms, hemoglobin level less than 10 g/dL, leukocyte count greater than 25 × 109/L, and circulating blast cells 1% or greater as predictors of shortened survival. Based on the presence of 0 (low risk), 1 (intermediate risk-1), 2 (intermediate risk-2) or greater than or equal to 3 (high risk) of these variables, 4 risk groups with no overlapping in their survival curves were delineated; respective median survivals were 135, 95, 48, and 27 months (P < .001). Compared with prior prognostic models, the new risk stratification system displayed higher predictive accuracy, replicability, and discriminating power. In 409 patients with assessable metaphases, cytogenetic abnormalities were associated with shorter survival, but their independent contribution to prognosis was restricted to patients in the intermediate-risk groups. JAK2V617F did not cluster with a specific risk group or affect survival.

OBJECTIVE. The goal of this study was to evaluate the effect of antibiotic administration before lumbar puncture on cerebrospinal fluid profiles in children with bacterial meningitis. METHODS. We reviewed the medical records of all children (1 month to 18 years of age) with bacterial meningitis who presented to 20 pediatric emergency departments between 2001 and 2004. Bacterial meningitis was defined by positive cerebrospinal fluid culture results for a bacterial pathogen or cerebrospinal fluid pleocytosis with positive blood culture and/or cerebrospinal fluid latex agglutination results. Probable bacterial meningitis was defined as positive cerebrospinal fluid Gram stain results with negative results of bacterial cultures of blood and cerebrospinal fluid. Antibiotic pretreatment was defined as any antibiotic administered within 72 hours before the lumbar puncture. RESULTS. We identified 231 patients with bacterial meningitis and another 14 with probable bacterial meningitis. Of those 245 patients, 85 (35%) had received antibiotic pretreatment. After adjustment for patient age, duration and severity of illness at presentation, and bacterial pathogen, longer duration of antibiotic pretreatment was not significantly associated with cerebrospinal fluid white blood cell count, cerebrospinal fluid absolute neutrophil count. However, antibiotic pretreatment was significantly associated with higher cerebrospinal fluid glucose and lower cerebrospinal fluid protein levels. Although these effects became apparent earlier, patients with ≥12 hours of pretreatment, compared with patients who either were not pretreated or were pretreated for &lt;12 hours, had significantly higher median cerebrospinal fluid glucose levels (48 mg/dL vs 29 mg/dL) and lower median cerebrospinal fluid protein levels (121 vs 178 mg/dL). CONCLUSIONS. In patients with bacterial meningitis, antibiotic pretreatment is associated with higher cerebrospinal fluid glucose levels and lower cerebrospinal fluid protein levels, although pretreatment does not modify cerebrospinal fluid white blood cell count or absolute neutrophil count results.

AbstractA venous thromboembolism (VTE) with the subsequent risk of pulmonary embolism is a major concern in the treatment of patients with multiple myeloma with thalidomide. The susceptibility to developing a VTE in response to thalidomide therapy is likely to be influenced by both genetic and environmental factors. To test genetic variation associated with treatment related VTE in patient peripheral blood DNA, we used a custom-built molecular inversion probe (MIP)–based single nucleotide polymorphism (SNP) chip containing 3404 SNPs. SNPs on the chip were selected in “functional regions” within 964 genes spanning 67 molecular pathways thought to be involved in the pathogenesis, treatment response, and side effects associated with myeloma therapy. Patients and controls were taken from 3 large clinical trials: Medical Research Council (MRC) Myeloma IX, Hovon-50, and Eastern Cooperative Oncology Group (ECOG) EA100, which compared conventional treatments with thalidomide in patients with myeloma. Our analysis showed that the set of SNPs associated with thalidomide-related VTE were enriched in genes and pathways important in drug transport/metabolism, DNA repair, and cytokine balance. The effects of the SNPs associated with thalidomide-related VTE may be functional at the level of the tumor cell, the tumor-related microenvironment, and the endothelium. The clinical trials described in this paper have been registered as follows: MRC Myeloma IX: ISRCTN68454111; Hovon-50: NCT00028886; and ECOG EA100: NCT00033332.

Abstract This analysis assessed the efficacy and safety of lenalidomide + dexamethasone in patients with relapsed or refractory multiple myeloma (MM) previously treated with thalidomide. Of 704 patients, 39% were thalidomide exposed. Thalidomide-exposed patients had more prior lines of therapy and longer duration of myeloma than thalidomide-naive patients. Lenalidomide + dexamethasone led to higher overall response rate (ORR), longer time to progression (TTP), and progression-free survival (PFS) versus placebo + dexamethasone despite prior thalidomide exposure. Among lenalidomide + dexamethasone-treated patients, ORR was higher in thalidomide-naive versus thalidomide-exposed patients (P = .04), with longer median TTP (P = .04) and PFS (P = .02). Likewise for dexamethasone alone-treated patients (P = .03 for ORR, P = .03 for TTP, P = .06 for PFS). Prior thalidomide did not affect survival in lenalidomide + dexamethasone-treated patients (36.1 vs 33.3 months, P > .05). Thalidomide-naive and thalidomide-exposed patients had similar toxicities. Lenalidomide + dexamethasone resulted in higher rates of venous thromboembolism, myelosuppression, and infections versus placebo + dexamethasone, independent of prior thalidomide exposure. Lenalido-mide + dexamethasone was superior to placebo + dexamethasone, independent of prior thalidomide exposure. Although prior thalidomide may have contributed to inferior TTP and PFS compared with thalidomide-naive patients, these parameters remained superior compared with placebo + dexamethasone; similar benefits compared with placebo + dexamethasone were not evident for thalidomide-exposed patients in terms of overall survival. Studies were registered at http://www.clinicaltrials.gov under NCT00056160 and NCT00424047.

ABSTRACT The glycoprotein complex of paramyxoviruses mediates receptor binding and membrane fusion. In particular, the measles virus (MV) fusion (F) protein executes membrane fusion, after receptor binding by the hemagglutinin (H) protein. Structures and single amino acids influencing fusion function have been identified in the F-protein ectodomain and cytoplasmic tail, but not in its transmembrane (TM) region. Since this region influences function of the envelope proteins of other viruses, we examined its role in the MV F protein. Alanine-scanning mutagenesis revealed that an F protein with a single mutation of a central TM region leucine (L507A) was more fusogenic than the unmodified F protein while retaining similar kinetics of proteolytic processing. In contrast, substitution of residues located near the edges of the lipid bilayer reduced fusion activity. This was true not only when the mutated F proteins were coexpressed with H but also in the context of infections with recombinant viruses. Analysis of the H-F complexes with reduced fusion activities revealed that more precursor (F 0 ) than activated (F 1+2 ) protein coprecipitated with H. In contrast, in complexes with enhanced fusion activity, including H-F L507A , the F 0 /F 1+2 ratio shifted toward F 1+2 . Thus, fusion activity correlated with an active F-H protein complex, and the MV F protein TM region modulated availability of this complex.