When to Consider Inborn Errors of Immunity
Dr. Kumar said he sees about 50 patients a week. Among these, about two to three patients will have some immune deficiency requiring treatment.
The podcast host, Jonathan Hausmann, MD, a pediatric and adult rheumatologist in Boston, asked Dr. Kumar to share examples of when rheumatologists should think about inborn errors of immunity.
Dr. Kumar shared a few tips:
Family history: Ask about a family history of immune deficiency. A patient may respond with something like, “Oh yes, my brother was tested for this, and he had a mutation in this gene.” If you don’t get information that readily, you can ask such questions as, “Do you have family members who died of infections really early?” or “What types of diseases run in your family?”
“If there’s a very strong family history of, say, lupus, we know there are genetic mutations and that complement deficiencies confer a great deal of susceptibility for lupus,” Dr. Kumar said.
Recurrent infection: Another area to consider is whether the patient has recurrent infections—for example, multiple ear infections in adults without a structural reason or two or more sinus infections in a year, but doesn’t have allergies. “It’s not just the recurrent nature of these infections, but also the severity,” he said. An example of this severity could be a 30-year-old patient who is fine and then ends up quickly in the intensive care unit for an adenovirus infection.
Also, rheumatologists should watch out for severe autoimmune cytopenias, such as a patient with rheumatoid arthritis who goes on methotrexate and develops a surprising number of infections.
Chronic diarrhea: Another warning sign is chronic diarrhea with weight loss because many conditions within immune deficiency have this symptom. “Alternately, chronic diarrhea could be causing a loss of certain types of immunoglobulin and, therefore, causing more immune deficiency,” he said.
Example
Paying close attention to a patient’s history is important. Dr. Kumar shared the example of a patient who had a positive anti-nuclear antibody of 1:160 and was seen for what was thought to be fibromyalgia. Going further into the patient history, Dr. Kumar found the patient had a history of previous sinusitis that was just described as allergies, but she had never been tested for allergies.
“As I was taking the history, I didn’t hear anything that sounded strongly allergic in nature,” he said.
