Autoimmune diagnoses may obscure primary immunodeficiency

Although infections are the hallmark of primary immunodeficiencies (PIs), autoimmunity, in which the immune system attacks healthy organs and tissue, can be a major symptom as well. Newly released data from the Immune Deficiency Foundation’s 2023 National Patient Survey confirms the overlap between PI and autoimmune conditions but also suggests that the presence of a diagnosed autoimmune condition may delay PI diagnosis.

The foundation conducted its sixth National Patient Survey to gather data on the overall status of individuals with PI in the U.S. Like previous patient surveys, the questions focused on the circumstances of diagnosis with PI, co-occurring conditions, treatments, health-related challenges, and quality of life. The survey was mailed to 4,500 people either with PI or who are caretakers of a child with PI who are new constituents since the last patient survey was completed in 2017. From January to April 2023, 1,177 completed surveys were returned. 

As expected, 91% of respondents reported serious, unusual, or recurrent infections prior to their PI diagnosis and 86% chose infections as at least one reason why they were tested for PI. 

Interestingly, almost a third (32%) of respondents reported being diagnosed with an autoimmune condition before they were diagnosed with PI. Of respondents with a prior autoimmune diagnosis, less than half (43%) selected “autoimmune condition” as a reason they were tested for PI. More than a third (39%) selected only infection-related reasons for being tested for PI. This pattern suggests that autoimmunity and susceptibility to infection are viewed as separate, unrelated conditions in many people who are ultimately diagnosed with PI. Greater awareness of the autoimmune aspects of PI could help individuals who present with both types of symptoms receive a diagnosis.

For the 91% of respondents who reported infections before their PI diagnosis, the time between when those infections started and when they were diagnosed with PI was calculated in years as their time to diagnosis. Respondents diagnosed with autoimmune conditions before they were diagnosed with PI were significantly more likely to have a time to diagnosis greater than 10 years compared to those with no prior autoimmune diagnosis.

This data again suggests that autoimmune conditions can obscure the underlying PI. It’s possible that the underlying PI is literally hidden by treatments for autoimmune conditions that suppress the immune system or that healthcare professionals are more focused on the autoimmune condition and overlook other symptoms.

Those diagnosed with autoimmune conditions before their PI diagnosis reported significantly poorer general physical health but their reported general mental health was comparable to those without a prior autoimmune diagnosis. General physical and mental health were measured using the PROMIS Global Health quality of life questions. Poorer physical health could be the result of delayed PI diagnosis or of more co-occurring diagnoses in this group. 

Observations on autoimmunity in PI are just one aspect of the 2023 National Patient Survey data. Check out the interactive report to explore more findings or download the full analysis.