Clinical immunoassay of platelet-rich plasma lysate therapy in urgent keratoplasty in patients with keratolysis

BACKGROUND: Published data show that one third of patients who underwent urgent keratoplasty experience graft melting, resulting in repeated corneal transplantation. However, no dedicated studies have been conducted to determine causes of keratolysis and ways to address them in patients with urgent corneal disorder. AIM: The study aimed to evaluate the effectiveness of platelet-rich plasma lysate in urgent corneal transplantation in patients with keratolysis based on the data of a comprehensive clinical immunoassay. METHODS: A comparative cohort study was conducted. A total of 50 patients with lysis of the cornea and corneal graft were examined. All patients underwent urgent keratoplasty. Patients were divided into two groups based on postoperative therapy. The first group included 30 patients receiving standard post-transplant therapy. The second group included 20 patients who additionally received subconjunctival injections and instillations of platelet-rich plasma lysate until the graft was completely epithelized. Whole blood samples were used for immunoassay. Phenotyping was performed by flow cytometry. RESULTS: Prior to keratoplasty, the following common characteristic changes were found in lymphocytes of patients with lysis of the cornea and corneal graft: an increase in absolute total CD3+ lymphocyte count; main regulatory T cell subpopulations, T helpers (CD3+CD4+); cytotoxic cells (CD3+CD8+), a minor subpopulation of double-positive T cells (CD3+CD4+CD8+), B lymphocytes (CD19+), and natural killer cells (CD16+CD56+) (p 0.05). Postoperatively, patients with poor keratoplasty outcome demonstrated a further increase in absolute lymphocyte and total T and B cell count and unchanged high count of natural killer cells. Favorable keratoplasty outcomes are explained by positive changes in the T cell subpopulations, which were most pronounced in the platelet-rich plasma group with a decrease in lymphocyte count (CD45+), including total CD3+ lymphocyte, T helper cell, and double-positive T lymphocyte count. CONCLUSION: Clinical observations suggest that addition of platelet-rich plasma lysate to therapy in patients after primary and repeat urgent transplantation was more effective than standard postoperative therapy. This is confirmed by corneal engraftment in all patients in the platelet-rich plasma lysate group compared with the standard therapy group, where a favorable outcome was reported in only one third of cases.