Improvement of lymphocyte proliferation assessment in non-immediate drug
hypersensitivity reactions using flow-cytometry
Abstract
Background. Lymphocyte transformation test (LTT) has been widely used to
evaluate non-immediate drug hypersensitivity reactions (NIDHRs).
However, the lack of standardisation and the low sensitivity have
limited its routine diagnostic use. The drug presentation by dendritic
cells (DCs) and the assessment of proliferation on effector cells have
shown promising results. Flow-cytometry-based methods can help apply
these improvements. We aimed to assess the added value of using
drug-primed-DCs and the determination of the proliferative response of
different lymphocyte subpopulations in NIDHRs. Methods. Patients with
confirmed NIDHR were evaluated by both conventional (C-LTT) and with
drug-primed-DCs LTT (dDC-LTT) analysing the proliferative response in
T-cells and other effector cell subpopulations by using the fluorescent
molecule, carboxyfluorescein diacetate succinimidyl ester. Results. The
C-LTT showed a significantly lower sensitivity (33.3%) compared with
dDC-LTT (65.2%), which was confirmed analysing each particular clinical
entity: SJS-TEN (62.5% vs 87.5%), MPE (14.3% vs 41.7%), and AGEP
(33% vs 80%). When including the effector cell subpopulations involved
in each clinical entity,
CD3++CD4+Th1 cells
in SJS-TEN,
CD3++CD4+Th1+NK
cells in MPE, and CD3++NK cells in AGEP, we could
significantly increase the sensitivity of the in vitro test to 100%,
66.6%, and 100%, respectively. With an overall sensitivity of 87% and
85% of specificity in NIDHR. Conclusions. The use of a
flow-cytometry-based test, DCs as drug presenting cells, and focussing
on effector cell subpopulations for each clinical entity significantly
improved the drug-specific proliferative response in NIDHRs with a
unique cellular in vitro test.