TITLE:
CD16+ Monocyte Subsets in Patients with Total Joint Arthroplasty
AUTHORS:
David C. Markel, Nancy M. Jackson, Jeffrey C. Flynn, Weiping Ren
KEYWORDS:
Osteolysis, Wear Debris, CD14+CD16+ Monocytes, Aseptic Loosening, AL, Flow Cytometry
JOURNAL NAME:
Open Journal of Orthopedics,
Vol.7 No.8,
July
28,
2017
ABSTRACT: Objective: There are two monocyte populations in human blood: CD14+CD16- classical
monocytes and CD14+CD16+ inflammatory monocytes. CD14+CD16+ inflammatory monocytes, account for
approximately 10% of the total monocytes, may be expanded in various types of inflammatory
conditions. The purpose of this study was to investigate whether the
expansion of the CD14+CD16+ monocyte population represents a risk factor of aseptic loosening (AL). Methods: Peripheral monocytes subsets were measured in revision patients with AL (n =
35) and in patients with stable implants (SI, n = 56). The gene profiles of TNFα, IL-1β, CD16, CD68 and TRAP5B from collected loosening periprosthetic
tissues were analyzed. Results: There were no significant differences in
the CD14+CD16+ monocyte populations between the SI and AL patients. The CD14+CD16+ monocytes were marginally higher in revision patients with
osteolysis (n = 30), compared to patients without osteolysis (n = 5) though no
statistically difference was found. There
was an association between the CD14+CD16+ monocyte subpopulation and the tissue gene profiles, including IL-1β (p = 0.063), CD68 (p = 0.036), and
TRAP5B (p = 0.073). Conclusion: It
was demonstrated that the expansion of
CD14+CD16+ monocytes reflects, to some extent, the
inflammatory status of the loosening periprosthetic tissues. It is unclear if some
of those SI patients (no pain and negative radiograph) who have a higher
frequency of CD14+CD16+ monocytes may be at the early
stage of AL. Further evaluation of CD14+CD16+ monocyte
population, independently or combined with other factors, will be useful to
design a risk profile for AL incidence and progression.