Adalimumab Increases Infection Risk 53% in Hidradenitis Suppurativa Patients Compared to Psoriasis
Key Insights
Adults with hidradenitis suppurativa (search) treated with adalimumab face a 53% higher risk of serious infections requiring hospitalization compared to psoriasis (search) patients on the same therapy.
The study of 10,349 patients found HS patients had significantly increased rates of sepsis (search) and genitourinary infections (search), with longer hospital stays.
Researchers emphasize the need for tailored infection-prevention strategies and closer monitoring for the HS population receiving adalimumab treatment.
Adults with moderate to severe hidradenitis suppurativa (search) (HS) treated with adalimumab face a significantly higher risk of serious infections compared to those with psoriasis (search) receiving the same therapy, according to a new retrospective cohort study published in JAMA Dermatology. The research reveals a 53% increased risk of hospitalization from noncutaneous infections in HS patients, highlighting critical safety considerations for this vulnerable population.
Study Design and Patient Population
The investigative team, led by Bruna Galvao de Oliveira Wafae, MD, MMSc, from Brigham and Women's Hospital Department of Dermatology, analyzed deidentified insurance claims from the MarketScan database. The study evaluated outcomes among adult patients diagnosed with HS or psoriasis (search) who initiated adalimumab therapy between January 2017 and December 2020, with analysis conducted from October 2023 to March 2024.
Among 10,349 new adalimumab users included in the study, 1,650 had HS and 8,699 had psoriasis (search). The mean age across the cohort was 44.8 years, with 54.5% being female. Patients with HS were notably younger than those with psoriasis, with a mean age of 36.2 years versus 46.5 years, and were more likely to be female (77.0% versus 50.2%). The HS cohort also exhibited higher rates of comorbidities including Crohn disease (search), obesity (search), anxiety (search), and depression (search).
Infection Risk Findings
The weighted Cox regression analysis demonstrated that HS was associated with a greater risk of serious infection compared with psoriasis (search), with a hazard ratio of 1.53 (95% CI, 1.34–1.86). This translates to a 53% higher risk of hospitalization from noncutaneous infections in the HS population.
"Our study found that among adalimumab users, patients with HS had a 53% higher risk of hospitalization from NCI [noncutaneous infection] compared with patients with psoriasis (search)," the researchers wrote. "Our analytical framework was designed to adjust for the immunomodulatory impact of standard therapies and the potential contribution of disease severity to infection risk."
Specific Infection Patterns
The study revealed distinct infection profiles between the two patient populations. HS patients showed significantly increased rates of genitourinary infections (search) with an incidence rate ratio (IRR) of 2.22 (95% CI, 1.22–3.86) and sepsis (search) with an IRR of 2.07 (95% CI, 1.35–3.12). Additionally, HS patients had 28% higher odds of extended hospitalization, with an odds ratio of 1.28 (95% CI, 1.13–1.45).
"The nature of infections also varied, with patients with HS more frequently experiencing sepsis (search) and genitourinary tract infections," the researchers noted.
Clinical Implications
The findings suggest an inherently higher baseline risk of severe infections in the HS population beyond the immunosuppressive effects of adalimumab therapy. Adalimumab, marketed as Humira by AbbVie (search), is a recombinant human immunoglobulin G1 monoclonal antibody that targets tumor necrosis factor (search) and was first approved by the FDA in 2002.
The research team emphasized that despite recent data suggesting increased prevalence of systemic infections among those with HS versus psoriasis (search), previous studies were limited as they did not adjust for individual risk factors. "Therefore, our study aims to compare the risk of hospitalization from noncutaneous infections, the infection profiles, and the length of stay for these infections between HS and psoriasis, thus providing a more focused evaluation of the HS-specific infection burden," Wafae and colleagues wrote.
Study Limitations and Future Directions
The researchers acknowledged several limitations, including the lack of adjustment for adalimumab dose-response relationships and steroid or chronic antibiotic use. The HS identification algorithm, based on a single ICD-10 code with prescription data, lacked formal validation and risked misclassification.
"Future studies will be important to further understand the risk of infection in this population, focusing on the contribution of the disease severity and therapeutic regimens, as well as investigating prophylactic strategies to reduce infection burden in the HS population," the researchers concluded.
The findings underscore the need for tailored infection-prevention strategies for HS patients receiving adalimumab, including enhanced monitoring protocols for sepsis (search) and genitourinary infections (search), and consideration of prophylactic measures to mitigate infection risk in this high-risk population.