A 35-year-old man with a late-onset combined immunodeficiency (LOCID) variant of common variable immunodeficiency, severe plaque psoriasis, psoriatic arthritis, and Crohn's disease attended Regional Hospital of Presidente Prudente and HC-FMUSP, São Paulo, Brazil. Anti-IL-12/IL-23 (ustekinumab) monoclonal antibody was prescribed due to failure of other treatments (phototherapy, oral acitretin) for psoriasis and Psoriasis Area Severity Index <10. We evaluated the impact of ustekinumab, a potent immunosuppressor, on the risk of infectious diseases in this patient followed for 8 years. Four quarterly doses of ustekinumab 90 mg and human immunoglobulin replacement (10,000 mg at 28-day intervals) were administered. Immunophenotyping, culture of lymphocytes, genetic sequencing, and whole exome sequencing were performed to investigate the primary immunodeficiency. Normal lymphocyte proliferation, absence of pathogenic variants in the genes analyzed and no clinically significant variants were detected in the whole exome. The main infections included chronic sinusitis, tonsillitis, fungal and bacterial otitis, gastroenteritis, and community-acquired pneumonia. The patient was infected with COVID-19, dengue (twice), and influenza and was hospitalized three times for intravenous antibiotic therapy. Ustekinumab did not influence susceptibility to severe infections and significantly improved psoriasis, psoriatic arthritis, and Crohn's disease in a patient with LOCID.

Ustekinumab, a new anti-interleukin-12/23 antibody, is an effective treatment for ulcerative colitis; however, data regarding predictive factors of its efficacy are limited. This study aimed to identify biomarkers that can predict the long-term outcome of ustekinumab treatment. We retrospectively reviewed the records of patients with active ulcerative colitis treated with ustekinumab at our hospital from June 2020 to January 2023. We divided patients into non-remission and remission groups, and examined whether baseline biomarkers, including C-reactive protein-to-lymphocyte ratio, and early treatment response could predict clinical remission at week 48 of ustekinumab treatment. Of the 33 patients included in the study, 21 (63.6%) were in clinical remission at week 48 of ustekinumab treatment. The baseline C-reactive protein-to-lymphocyte ratio value was identified as an independent prognostic factor for clinical remission at week 48 (odds ratio: 10, 95% confidence interval: 1.6–62.4, p=0.014), with the cutoff value of 3.353 showing excellent prognostic performance (sensitivity: 71.4%, specificity: 83.3%). Furthermore, the clinical response at week 4 (p=0.009) and that at week 8 (p=0.005) were significantly associated with clinical remission at week 48. The baseline C-reactive protein-to-lymphocyte ratio value and early treatment response are useful biomarkers to predict the long-term efficacy of ustekinumab treatment.

Inflammatory bowel diseases, comprising Crohn’s disease (CD) and ulcerative colitis (UC), are chronic, relapsing and remitting immune-mediated inflammatory diseases affecting the gastrointestinal tract. Ustekinumab (UST) is a monoclonal antibody blocking the p40 subunit of the anti-interleukin (IL) 12/23. Pivotal trials (CERTIFI and UNITI-IM for CD, UNIFI for UC) established the efficacy of UST for the induction and maintenance of remission in both CD and UC, with the most favorable results in naïve patients to biologics. In recent years, a wealth of ‘real-world’ data has emerged supporting positive clinical, endoscopic, and histological outcomes in patients treated with UST, as well as reassuring safety data. More recently, the results of the first head-to-head trials of UST and tumor necrosis factor (TNF) antagonists have been reported. Moreover, a number of studies exploring the role of UST in specific clinical settings, such as perianal CD, postoperative complications and recurrence, extraintestinal manifestations, chronic antibiotic-refractory pouchitis, and pregnancy, have been reported. This review explores results reported to date on UST, including those from pivotal trials, real-world data, and emerging studies regarding therapeutic drug monitoring and immunogenicity. The safety profile of UST was also reviewed.