Myeloma is characterized by stage-specific alterations in DNA methylation that occur early during myelomagenesis.

Epigenetic changes play important roles in carcinogenesis and influence initial steps in neoplastic transformation by altering genome stability and regulating gene expression. To characterize epigenomic changes during the transformation of normal plasma cells to myeloma, we modified the HpaII tiny fragment enrichment by ligation-mediated PCR assay to work with small numbers of purified primary marrow plasma cells. The nano-HpaII tiny fragment enrichment by ligation-mediated PCR assay was used to analyze the methylome of CD138(+) cells from 56 subjects representing premalignant (monoclonal gammopathy of uncertain significance), early, and advanced stages of myeloma, as well as healthy controls. Plasma cells from premalignant and early stages of myeloma were characterized by striking, widespread hypomethylation. Gene-specific hypermethylation was seen to occur in the advanced stages, and cell lines representative of relapsed cases were found to be sensitive to decitabine. Aberrant demethylation in monoclonal gammopathy of uncertain significance occurred primarily in CpG islands, whereas differentially methylated loci in cases of myeloma occurred predominantly outside of CpG islands and affected distinct sets of gene pathways, demonstrating qualitative epigenetic differences between premalignant and malignant stages. Examination of the methylation machinery revealed that the methyltransferase, DNMT3A, was aberrantly hypermethylated and underexpressed, but not mutated in myeloma. DNMT3A underexpression was also associated with adverse overall survival in a large cohort of patients, providing insights into genesis of hypomethylation in myeloma. These results demonstrate widespread, stage-specific epigenetic changes during myelomagenesis and suggest that early demethylation can be a potential contributor to genome instability seen in myeloma. We also identify DNMT3A expression as a novel prognostic biomarker and suggest that relapsed cases can be therapeutically targeted by hypomethylating agents.

The relationship between the serum free light chain assay and serum immunofixation electrophoresis, and the definition of concordant and discordant free light chain ratios.

"Stringent" complete remission in myeloma has been defined by a normal serum free light chain ratio (SFLCR) in addition to the standard criteria for CR. 2648 serial samples from 122 IgG or IgA myeloma patients were studied to explore the relationship between SFLCR and serum immunofixation electrophoresis (SIFE). SFLCR was normal in 34% of cases with positive SIFE and abnormal in 66%. SFLCR was normal in 69% of cases with negative SIFE and abnormal in 31%. When evaluated with SIFE as the benchmark, the sensitivity of SFLCR was 66% and specificity was 69%. These findings were unchanged when abnormal SFLCR values were classified as concordant (< 0.26 for lambda disease and > 1.65 for kappa) or discordant (< 0.26 for kappa disease and > 1.65 for lambda). Additional studies are required to determine the temporal relationship between SFLCR normalization and paraprotein clearance. Until then, the role of SFLCR in defining response remains controversial.

Acyclovir to prevent reactivation of varicella zoster virus (herpes zoster) in multiple myeloma patients receiving bortezomib therapy.

BACKGROUND: Humoral-mediated as well as cell-mediated immunity is compromised in myeloma patients receiving treatment. Immunocompromised patients are at risk of developing herpes zoster. There is evidence from clinical trials that bortezomib therapy is associated with a significant risk of herpes zoster. It is the authors' clinical policy to administer long-term acyclovir prophylactically to all symptomatic myeloma patients. METHODS: A retrospective review of the records of 125 myeloma patients who were treated with bortezomib and who also received routine acyclovir prophylaxis at the dose of 400 mg daily in >80% of patients was undertaken. Alternatives, used in <20% of patients, were 200 mg of acyclovir, 250/500 mg of valacyclovir, or 500 mg of famciclovir administered daily. This was accompanied by patient education regarding the importance of compliance with these prophylactic medications. RESULTS: The duration of bortezomib therapy was 1 to 164 weeks (median, 16 weeks). The total duration of exposure to bortezomib was 4150 weeks (80 patient-years). Except for the occasional missed dose, the self-reported compliance with antiviral prophylaxis was 100%. Not a single episode of herpes zoster was reported during this period. No adverse effects were noted that could be definitely attributed to acyclovir, valacyclovir, or famciclovir. CONCLUSIONS: Daily acyclovir (or a suitable alternative) appears to be effective at preventing herpes zoster virus in patients with myeloma who are receiving bortezomib, with or without corticosteroids.