Early Detection of Primary Antibody Deficiencies in Primary Care Facilities by an Algorithm Driven Selection of Serologic Testing in Individuals at Risk.

Rationale: Primary antibody deficiencies (PAD) encompass a group of rare heterogeneous diseases. The clinical presentation may vary widely, including infectious and autoimmune symptoms and increased risk of malignancy. Due to the rarity of the diseases and this wide array of symptoms there is often a delay in diagnosis, of up to 12 years on average1-4. Timely diagnosis of PAD reduces morbidity, mortality and health care costs as effective therapies are available. The currently available screening systems for the broader group of primary immunodeficiencies (PID) have been shown to have poor diagnostic performance5-10 and are time consuming. We have thus developed an algorithm to screen patient records in a primary care setting for risk factors specifically for PAD. Patients with a high risk may undergo a laboratory assessment and referral if necessary, thus reducing the diagnostic delay of PAD. The aim of the current study is to validate this algorithm.

Objective:

Main objective: to validate a screening algorithm for PAD in a primary care setting in the Netherlands.

Study design: Mono-centre cohort study based on regular care data

Study population: Primary care patients aged 12-70 years with the 100 highest scores based on our algorithm.