Prospective Piperacillin Lymphocyte Transformation Testing in Patients With Cystic Fibrosis Receiving Regular and Desensitization Courses of Piperacillin-Tazobactam.

Whitaker, P.; Gibson, A.; Farrell, J.; Gillgrass, L.; Meng, X.; Peckham, D.; Naisbitt, DJ.

Prospective Piperacillin Lymphocyte Transformation Testing in Patients With Cystic Fibrosis Receiving Regular and Desensitization Courses of Piperacillin-Tazobactam.

All Authors

Whitaker, P.

Gibson, A.

Farrell, J.

Gillgrass, L.

Meng, X.

Peckham, D.

Naisbitt, DJ.

LTHT Author

Whitaker, Paul
Gillgrass, Lindsey

LTHT Department

Adult Cystic Fibrosis Unit

Non Medic

Research Nurse

Publication Date

2025

Item Type

Journal Article
Observational Study

Abstract

BACKGROUND: Piperacillin-tazobactam is used in patients with cystic fibrosis to treat recurrent respiratory infections. Exposure is associated with a high frequency of nonimmediate hypersensitivity. OBJECTIVE: To assess the applicability of the lymphocyte transformation test (LTT) for the diagnosis of piperacillin hypersensitivity and the influence of desensitization on piperacillin-specific T-cell responses. METHODS: Study arm 1 was an analysis of LTT responses from 58 naive/baseline tolerant patients with samples collected over a 3-year interventional phase. In study arm 2, 17 hypersensitive patients were recruited and LTTs were conducted before and after desensitization. Clinical hypersensitivity reactions in both arms were monitored over an 8-year observational period. RESULTS: In study arm 1, 58 patients received 611 piperacillin-tazobactam courses (range, 2-40; mean +/- SD, 10.5 +/- 8.1) during the interventional phase; 11 patients developed hypersensitivity. The patients who remained tolerant received 236 piperacillin-tazobactam courses in the observational period, 9 of whom developed hypersensitivity. Ten of 11 interventional phase hypersensitive patients had a positive LTT whereas one remained negative. We recorded 136 negative LTTs with 39 tolerant patients, whereas eight patients had a positive LTT and four developed hypersensitivity during the observational period. Ten LTT-positive patients in study arm 2 underwent piperacillin-tazobactam desensitization, with seven tolerating the drug. The strength of the LTT decreased during desensitization, and negative results were recorded for a minimum of 14 days. During follow-up, eight patients tolerated 62 piperacillin-tazobactam courses through desensitization. CONCLUSIONS: The LTT is a sensitive marker of drug sensitization that could be used to inform future patient management. Desensitization is associated with attenuation of the piperacillin-specific T-cell response.