Analysis of Cell-Free DNA in the Precursor Stage of Waldenström's Macroglobulinemia

Abstract

IntroductionWaldenström’s Macroglobulinemia (WM) is a lymphoplasmacytic lymphoma characterized by the overproduction of monoclonal IgM antibodies. Monoclonal gammopathy of undetermined significance (MGUS) of the IgM type is its asymptomatic precursor. There is growing interest in utilizing cell-free DNA (cfDNA) from peripheral blood as a less invasive diagnostic tool, primarily through mutation analysis. Additionally, cfDNA quantification and fragmentomics profiling may have prognostic value in some cancers. However, it remains unclear whether these methods could be useful for risk stratification in IgM MGUS.Objective: The objective of this study was to assess the utility of cfDNA quantity and fragmentomics analysis in IgM MGUS to predict disease activity in IgM MGUS and its progression to WM.Materials and methods: Data were obtained from the population-based screening study Iceland Screens, Treats, or Prevents MM (iStopMM), which screens for MGUS. Five samples were collected from seven individuals who progressed from IgM MGUS to WM and from twelve individuals with IgM MGUS who did not develop WM. cfDNA was isolated from cell-free plasma using the Chemagic 360 instrument and quantified using a Qubit fluorometer. cfDNA fragment lengths were assessed with the Bioanalyzer. Differences in cfDNA concentration and fragment size between the groups were analyzed using a t-test.Results: A total of 94 cfDNA plasma samples were analyzed for both concentration and fragment length. Individuals who later progressed to WM had significantly higher cfDNA concentrations compared with stable IgM MGUS (52.6 ng/mL vs. 28.1 ng/mL; p <0.005). No statistically significant differences were observed in cfDNA fragment length between the two groups.Conclusion: cfDNA concentration is significantly higher in individuals with IgM MGUS who later progressed to WM. These findings suggest that cfDNA quantification may serve as a non-invasive prognostic marker for disease progression.

InngangurStórglóbúlíndreyri Waldenström (Waldenström‘s macroglobulinemia, WM) er eitilfrumukrabbamein með ofseytingu einstofna IgM mótefna. Góðkynja einstofna mótefnahækkun (monoclonal gammopathy of udertermined significance, MGUS) af IgM gerð er einkennalaust forstig WM. Áhugi hefur verið að því að nýta utanfrumuerfðaefni (cellfree DNA, cfDNA) í blóði til að bæta greiningu þessara sjúkdóma oftast með greiningu stökkbreytinga. Sýnt hefur verið að einfaldari mæling á magni og lengd cfDNA geti haft forspárgild um horfur í sumum krabbameinum. Ekki er þekkt hvort það geti gagnast í áhættustigun IgM MGUS.Markmið: Að kanna hvort tengsl séu milli magns og lengdar cfDNA við horfur í IgM MGUS.Aðferðir: Fengin voru gögn frá rannsókninni Blóðskimun til bjargar sem er lýðgrunduð skimunarrannsókn fyrir MGUS. Fengin voru fimm sýni frá sjö einstaklingum sem þróuðu með sér WM eftir greiningu IgM MGUS og tólf einstaklingum sem höfðu IgM MGUS og þróuðu ekki með sér WM. cfDNA var einangrað úr frumufríu plasma með Chemagic 360 og það magnmælt með Qubit tæki. Lengd cfDNA var svo metið með Bioanalyser. Magn og lengd cfDNA var borið saman með t-prófi.Niðurstöður: Alls voru 94 cfDNA plasma sýni magn- og lengdargreind. Þátttakendur sem greindust síðar með WM höfðu marktækt meira cfDNA en þeir sem höfðu stöðugt IgM MGUS (52,6 ng/mL vs 28,1 ng/mL; p=4,9×10-6 ). Ekki reyndist munur á lengd cfDNA búta.Ályktanir: Magn cfDNA er marktækt meira hjá einstaklingum með IgM MGUS sem síðar fá WM. Einföld magnmæling á cfDNA gætu þannig nýst til að spá fyrir um horfur í IgM MGUS.