Only limited data on laboratory parameter dynamics and safety under prolonged 
biologic treatment in a "real-world" scenario are available for recommendations 
on screening and monitoring. This study is a retrospective analysis of routine 
parameter dynamics and laboratory adverse events (LAE) in psoriasis patients on 
long-term treatment (n = 199) with tumour necrosis factor (TNF)-α-antagonists 
(adalimumab, etanercept), and the interleukin (IL)12/23-antagonist ustekinumab. 
Overall, neutrophil (PMN) counts (-11%) and triglycerides (+9%) changed 
considerably. TNF-α-antagonists and ustekinumab differentially affected 
lymphocyte counts (+13% and ±0%, respectively). Dynamics were pronounced during 
the first 180 days of treatment. In 340 treatment-years, 15 Common Terminology 
Criteria for Adverse Events (CTCAE) III-IV° LAE were recorded (11 involved liver 
enzymes). They prompted alteration of the biologic regime in only 2 cases. Age, 
sex, previous systemic treatments, and psoriatic arthritis did not significantly 
predict LAE. Liver enzyme and triglyceride screening may be warranted in some 
instances. Our data suggest that unguided monitoring of other routine laboratory 
parameters is unnecessary under long-term biologic treatment.