Investigation Identifies Factors Associated with Leukopenia in SJS/TEN

Leo L. Wang, MD, PhD

Stevens-Johnson syndrome toxic epidermal necrolysis (SJS/TEN), leukopenia, is characterized by impaired wound healing, severe disease, and sometimes mortality. It can present before or secondary to SJS/TEN, though the clinical characteristics and outcomes of those affected by it are not well understood due to limited data.

A team of investigators, led by Leo Wang MD, PhD, Department of Dermatology, Hospital of the University of Pennsylvania, Philadelphia, decided to examine this population in the setting of hospital admission. They looked at factors associated with leukopenia and the subsequent patients outcomes.

In the multi-institutional cohort analysis, baseline characteristics of patients admitted with luekopenia, defined by having a white blood cell count of less than 4000/μL, were compared to those without the condition. Logistic regression was used to evaluate the risk of in-hospital complications.

Understanding SJS/TEN and Leukopenia

A higher median body surface area percentage involvement was observed in patients with SJS/TEN on admission (30%) compared with those without leukopenia (15%). These patients also displayed higher rates of active malignant neoplasm (22.5% vs 9.5%), and connective tissue disease (22.5% vs 8.5%).

The study included 377 patients with a mean age of 50 years and 198 women (52.5%). Of the patient population, 49 (13%) patients had leukopenia at the time of admission. There was no difference in age or sex between the groups.

The use of leukopenia-inducing medication was present in 179 (47.5%) patients, but investigators found that those patients did not have develop the disease at higher rates compared to patients who were not taking drugs associated with SJS/TEN. Because of this finding, results suggest that in this cohort, leukopenia was not dependent on medication use.

Identifying Factors Associated with Leukopenia

Results identified from the multivariable logistic regression analysis, included body surface area involvement on admission, malignant neoplasm, and connective tissue disease as the independent factors associated with leukopenia in SJS/TEN.

Additional associations observed after a univariable logistic regression comprised of in-hospital complications of bacteremia and pnemonia. However, there was no correspondence between leukopenia and hospital complications like acute kidney failure, major thrombotic events, intubation, sepsis, cellulitis, urinary tract infection, or in-hospital mortality.

Without factoring in patients with fatal outcomes, those with leukopenia had a significantly longer length of stay in the hospital (15 days) compared with those without the disease (9 days).

"Additional prospective studies and clinical trials are necessary to confirm these observations and delineate the association between leukopenia and SJS/TEN," investigators wrote. "However, because leukopenia is common, these observations are important for current clinical practice. Dermatologists should be aware of this association to mitigate its effects. Therapeutic medications that may exacerbate leukopenia may be less desirable in such patients, whereas granulocyte colony-stimulating factor may warrant further study to assess the effect of leukopenia-directed therapies for SJS/TEN outcomes."

The study, "Prevalence of Leukopenia and Associated Outcomes in Patients With Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis" was published in JAMA Dermatology.