PMC6890602_01
Sequential anteroposterior radiographs of the patient's right knee indicate progression of bone loss and photographs of the right leg show persisting eczema. (A) Radiography prior to primary knee replacement depicts joint degeneration secondary to rheumatoid arthritis, 2009/03. (B) Pre-revisional radiograph indicates peri-implant bone loss and loosening of the tibial component, 2012/03. (C) Post-revisional radiograph depicts intense intraoperative usage of cement and progressive bone loss, 2012/07. (D) Radiographic status at the time of hypersensitivity diagnostics, 03/2018. (E) Latest radiographic status (patient in supine position), 01/2019. (F) Eczema at the time of hypersensitivity diagnostics, 03/2018. (G) Follow-up examination in the aftermath of rituximab therapy indicated an unimproved cutaneous status, 03/2019.
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We report the case of a 71-year-old female patient with chronic RA who presented at our institution 4 years after right-sided re-re-revision total knee arthroplasty with debilitating chronic pain, swelling, and severely itchy eczema (2014/03-2018/03) (Figure 1).
Lymphocyte transformation test (LTT) and T cell subsets analyses point toward T cell mediated hypersensitivity as the root cause for local inflammation. (A) Exposure to various arthroplasty-relevant noxae revealed increased T cell proliferation following cobalt and nickel exposure. Mean stimulation index (proliferation with antigen divided by proliferation without antigen) values (n = 3) of >2 indicate marginal sensitization and values >3 can be considered positive. (B) Scatter dot plots of circulating T helper cells (CD4+) and cytotoxic T cells (CD8+) indicate abundance of effector memory T cells in the synovium of the affected knee. MMA, methyl methacrylate; N,N-D4T, N,N-dimethyl-p-toluidine; BPQ, benzoyl peroxide; HQ, hydroquinone; GM, gentamicin.
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T cells (Figure 2A). In particular, 66.5% of all CD4+ and 51.2% of all CD8+ T cells belonged to the effector memory compartment, which represents an 8-fold increase in CD4+ T cells and a 4-fold increase in CD8+ T cells when compared to peripheral blood levels (Figure 2B).