Utility of testing for monoclonal bands in serum of patients with suspected osteoporosis: retrospective, cross sectional studyBMJ 2005; 330 doi: https://doi.org/10.1136/bmj.38376.401701.8F (Published 07 April 2005) Cite this as: BMJ 2005;330:818
- Bo Abrahamsen, consultant ()1,
- Ivan Andersen, staff specialist2,
- Susanne S Christensen, registrar1,
- Jonna Skov Madsen, staff specialist3,
- Kim Brixen, consultant1
- 1 Department of Endocrinology, Odense University Hospital, DK-5000 Odense C, Denmark,
- 2 Department of Haematology, Odense University Hospital,
- 3 Department of Clinical Biochemistry, Odense University Hospital
- Correspondence to: B Abrahamsen
- Accepted 14 January 2005
Objective To determine whether measuring monoclonal bands (M component) in serum should be part of the investigation of patients referred to osteoporosis clinics.
Design Retrospective, cross sectional, observational study.
Setting Referral centre for osteoporosis in a university hospital, Denmark.
Participants 799 people (685 women) aged 19 to 94 years newly referred with suspected osteoporosis.
Main outcome measures Proportion of patients fulfilling the Nordic Myeloma Study Group definition for target condition and proportion of patients with other important haematological conditions.
Results 4.9% (18 of 366) of patients with osteoporosis and 2.2% (9 of 408) of patients without osteoporosis had M component in serum (χ2 = 3.66, P = 0.04). Multiple myeloma was diagnosed in three patients with osteoporosis (absolute risk 0.8%, 95% confidence interval 0.11% to 1.7%). The relative risk of multiple myeloma in patients presenting with osteoporosis was 75 (10 to 160). As a diagnostic test for multiple myeloma in patients with osteoporosis, M component in serum had a specificity of 95.0% and a positive predictive value of 17.6%. 122 blood electrophoreses were carried out for each case of multiple myeloma diagnosed. All patients with multiple myeloma had a history of fragility fractures. If lymphoma was included as a target condition, the specificity increased to 95.3% and the positive predictive value increased to 23.5%. Monoclonal gammopathy of undetermined significance was diagnosed in 13 (3.6%) participants with osteoporosis and in eight (2.0%) participants with normal bone mineral density or osteopenia.
Conclusions Patients presenting with osteoporosis should be tested for M component in serum, as 1 in 20 patients with newly diagnosed osteoporosis had multiple myeloma or monoclonal gammopathy of undetermined significance.
Contributors All authors conceived and designed the study and wrote the manuscript. SSC reviewed patient notes. IA reviewed the pathology reports and haematology notes. JSM provided clinical chemistry expertise and data. KB supervised the study. BA collated densitometry data and carried out the standards for reporting of diagnostic accuracy analysis.19 BA is guarantor.
Funding BA is the recipient of a clinical research grant from the Novo Nordisk Foundation.
Competing interests None declared.
Ethical approval Not required.
- Accepted 14 January 2005