Background Polyclonal hypergammaglobulinaemia (PH) represents a classic diagnosis problem in internal medicine. However, there is no consensus threshold for PH. The aim of this study was to define a threshold for PH.
Methods We conducted a retrospective multicentric study using laboratory biological databases between 1 January 2016 and 31 December 2016 in two university hospitals and one non-university hospital. All patients 18 years old or over and with at least one serum protein electrophoresis (SPE) available in 2016 were included. Exclusion criteria were monoclonal, biclonal, or oligoclonal spikes or, in case of hypogammaglobulinaemia, proven free light chain gammopathy. The main endpoint was to define the threshold values for PH in this population. Another objective was to define the 95th percentile of the distribution.
Results 20 766 SPEs were included in this cohort. The PH threshold on 95th percentile was 18.9 g/L. The threshold varied according to geographical areas.
Conclusions This is the first study to scientifically define a PH threshold. The main limitation is that our threshold is only biological. The study was not designed to associate this threshold with a clinically active disease. In conclusion, while the 19 g/L cut-off seems the most relevant threshold, but it will need to be validated by prospective studies.
- adult pathology
Data availability statement
All data relevant to the study are included in the article or uploaded as online supplemental information. All data are available in study.
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Contributors Conception of the study: MM, MP, CB and CB. Inclusion of data : FJ, TD, PL, AG, PM and PR. Analysis: all authors. Writing and validation of manuscript: all authors.
Author acting as guarantor : CB
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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