Lymphopenia Better Prognosticator vs Blood Cell Counts in Epidermal Necrolysis

Lymphopenia may be a better prognostic biomarker than overall white blood cell counts in participants with epidermal necrolysis (EN), according to research letter findings published in Journal of the American Medical Association Dermatology.

Researchers conducted a retrospective cohort study of 147 participants (65% women; 17% cancer history) treated in a French reference center from January 2015 until July 2022. Participants with abnormal and normal blood neutrophil (abnormal, n=11; 36% women, median age, 60 years [IQR, 47-67]; normal, n=136; 67% women, median age, 46 years [IQR, 35-64]) and lymphocyte (abnormal, n=80; 55% women, median age, 52 years [IQR, 43-66]; normal, n=67, 76% women, median age, 41 years [IQR, 31-60]) counts were compared for baseline sex, age, cancer history, initial body and surface area detached. They were also evaluated for toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), intensive care unit (ICU) admission, bloodstream infections, and death at 6 weeks.

There were 21.8% (n=32) of participants with EN had leukopenia at baseline. A total of 54.4% (n=80) of participants and 7.5% (n=11) of participants experienced lymphopenia. Those with lymphopenia were more often older, male, had more severe disease at baseline, had a higher rate of infections and ICU admission, and had poorer outcomes vs participants without lymphopenia (mortality rate, 30.0% vs 5.6%, respectively; P =.001).

In participants with or without neutropenia, there were no significant differences noted in baseline characteristics or outcomes. It was noted that there was an abnormal neutrophil count vs normal neutrophil count final diagnosis in 45.5% of participants with TEN vs 48.5%, in 27.3% of participants with overlap vs 22.1%, and in 27.3% of participants with SJS vs 29.4%, respectively.

There was an abnormal lymphocyte count vs normal lymphocyte count final diagnosis in 55% of participants with TEN vs 40.3%, 21.2% of participants with overlap vs 23.9%, and 23.7% of participants with SJS vs 35.8%, respectively. This suggested lymphocyte counts at baseline are more involved as a prognosis factor then neutrophils, and lymphopenia might be a better prognostic biomarker than overall white blood cell counts in participants with EN.

There was no significant difference in the in-hospital mortality rate between participants with leukopenia (21.9%) and participants without leukopenia (18.8%; P =.69). Death at week 6 was experienced by 3 participants with abnormal neutrophil counts and 25 participants with normal neutrophil counts, and by 24 participants with abnormal lymphocyte counts and 4 participants with normal lymphocyte counts.

Study limitations include the nature of single-center and retrospective design, and unaccounted-for time lag between first symptoms and leukocyte counts varied between participants.

“Lymphopenia, which is associated with a more severe disease, a higher rate of infections and intensive care unit admission, and a higher in-hospital mortality rate, might be a better prognostic biomarker in participants with EN than the overall white blood cell counts,” conclude the researchers.