Abstract
Objectives: Myeloma is characterised by the presence of monoclonal immunoglobulin (M-protein) and the free light chain (FLC) in blood. We investigated whether these M-proteins and FLC are detectable in myeloma patients’ saliva to evaluate its utility for non-invasive screening and monitoring of haematological malignancies. Methods: A total of 57 patients with monoclonal gammopathy and 26 age-matched healthy participants provided paired serum and saliva samples for immunoglobulin characterisation and quantification. Results: Myeloma patients had IgG or IgA M-protein levels ranging up to five times and FLC levels up to a thousand times normal levels of polyclonal immunoglobulins. Despite these highly elevated levels, only two IgG and no IgA M-proteins or FLC could be detected in paired saliva samples. Most patients had reduced levels of serum polyclonal immunoglobulins, but all had normal levels of salivary IgA. Conclusions: Immunoglobulin transfer from blood is not determined by levels in the systemic circulation and more likely dictated by periodontal inflammation and the integrity of the oral epithelium. Immunoglobulins secreted by bone marrow plasma cells do not substantially enter saliva, which represents a poor medium for myeloma diagnosis. These findings, along with normal salivary IgA levels despite systemic immunoparesis, support a strong partitioning of oral from systemic humoral immunity.
Original language | English |
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Pages (from-to) | 493-502 |
Number of pages | 10 |
Journal | European Journal of Haematology |
Volume | 108 |
Issue number | 6 |
Early online date | 20 Feb 2022 |
DOIs | |
Publication status | Published - 30 Jun 2022 |
Bibliographical note
Funding Information:This research received no specific grant from any funding agency in the public, commercial or not-for-profit sector. We are grateful to all participants and patients and patient's clinical teams at centres in Birmingham and Bath whose participation made this study possible.
Keywords
- haematological neoplasms
- immunity, humoral
- immunoglobulin light chains
- immunoglobulins
- multiple myeloma
- paraproteins
- plasma cells
- saliva
ASJC Scopus subject areas
- Hematology