Doctoral Defense in Biomedical and Health Sciences

On Friday, June 20, 2025, Jón Þórir Óskarsson will defend his doctoral thesis in Biomedical and Health Sciences at the Faculty of Medicine, University of Iceland.
The thesis is titled: Insights from the bone marrow: Characterization of monoclonal gammopathy of undetermined significance through flow cytometry analysis of plasma cells.

The opponents are Dr. Kwee Yong, Professor at the Cancer Institute, University College London, and Mona Høysæter Fenstad, Consultant at St. Olavs Hospital in Trondheim.

The main supervisor was Professor Sigurður Yngvi Kristinsson. Also serving on the doctoral committee were Professor Alberto Orfao, Specialist Róbert Pálmason, and Researcher Sigrún Þorsteinsdóttir.

Professor Sædís Sævarsdóttir, Vice Head of the Faculty of Medicine, will chair the defense, which takes place in the Ceremonial Hall (Hátíðasalur) of the University of Iceland and begins at 9:00 a.m.

Abstract

Multiple myeloma (MM) is a hematological malignancy characterized by the proliferation and accumulation of malignant plasma cells in the bone marrow (BM). MM is consistently preceded by monoclonal gammopathy of undetermined significance (MGUS), a common, asymptomatic condition affecting 3-5% of individuals aged 50 or older, with a variable risk of progression to MM and related diseases. This PhD thesis evaluates the clinical utility of multiparametric flow cytometry (MFC) in the diagnostic evaluation of MGUS through three studies based on the analysis of BM samples from participants in the Iceland Screens, Treats, or Prevents Multiple Myeloma (iStopMM) population-based screening study. In the first study, a Bone Marrow Quality Index (BMQI) was developed to objectively assess the quality of BM aspirate samples based on the distribution of BM-associated cell populations indicative of hemodilution. The second study refines the serum free light-chain ratio cutoff used for diagnosing light-chain MGUS, demonstrating improved specificity as a surrogate marker of plasma cell clonality. The third study investigated the frequency and clinical significance of clonal plasma cell detection in IgA and IgG MGUS, identifying a subgroup characterized by the absence of clonal plasma cells, transient or stable low-level IgG M-proteins, and no evidence of disease progression. Collectively, these findings highlight the value of MFC-based characterization of MGUS, enhancing diagnostic precision and enabling more accurate risk stratification.

About the doctoral candidate

Jón Þórir Óskarsson was born in 1990 in Akranes. He graduated from the natural sciences track at Fjölbrautaskólinn í Garðabæ in 2010, earned a B.Sc. in biology from the University of Iceland in 2014, and an M.Sc. in Biomedical and Health Sciences from the same university in 2017. Since then, Jón Þórir has worked on the research project Blóðskimun til bjargar (Life-Saving Blood Screening), focusing on multiple myeloma and its precursors. This work led him to begin his PhD studies in Biomedical and Health Sciences at the University of Iceland in 2021. The research project received funding from the Icelandic Cancer Society Research Fund.

Alongside his doctoral studies, Jón Þórir has taught and supervised students at the University of Iceland and worked in the hematopathology research lab at Landspítali – The National University Hospital of Iceland.
His parents are Rósa Jónsdóttir and Óskar Þórðarson. Jón Þórir has two children, Kolbeinn (7 years old) and Kristín (5 years old).