Single center case-control study in Lombardia, Italy, of 1193 psoriasis patients treated with biologics compared to the Lombardia population as controls, assessing the risk of contracting COVID-19, and analysing mortality, and ICU admission rates. Furthermore severity of COVID-19 disease was reviewed.
Included psoriasis patients were adults, had moderate to severe disease and used approved anti-psoriatic monotherapy in the maintaining phase. Used medications include: TNFalpha inhibitors, IL 12/23 inhibitors, IL 17, IL 23 inhibitors and small molecules. Demographic and clinical characteristics of cases and controls were similar.
Patients under biologicals were at higher risk of testing positive for COVID 19 (OR 3.43(95% CI 2.25-5.75), more at risk of being self quarantained at home (OR 9.05) and more at risk of being hospitalized (OR 3.49) compared to controls. There was no statistical higher risk of ICU admission or death.
Authors discuss the fact that patients on biologicals might be at risk for respiratory infections, but the detrimental hyperinflammatory phase of COVID-19 as seen in the regular population occurred not in this study group and therefore might have protecte dpatients on biologicals from progression to extrapulmonary manifestations and death.
Limitations: there has not been and adjustment for, i.e. COPD patients or other patients with a known increased risk of severe COVID-19 disease. Furthermore, there hasn’t been a detailed sub analysis of which inhibitors are more or less effective at potentially preventing severe COVID-19. It is important to acknowledge that psoriatic patients on biologicals do show an increased risk of contracting mild-to-moderate COVID-19
Questions for further research include the role of the blocked interleukins in COVID-19. Does a similar pattern occur in i.e. asthma patients on asthma biologicals?

This article was selected by FJS van der Velden, MD (resident paeds) & G. Tramper, PhD, MD (paediatrician, paediatric infectiologist).