JMIR Publications

ABSTRACT

Background:

While fever is considered an initial sign of infection, many individuals with primary immunodeficiency (PI) anecdotally report a lower than normal average body temperature on online PI forums sponsored by the Immune Deficiency Foundation (IDF). There is limited knowledge about the average body temperature and fever response in individuals with PI.

Objective:

To compare median body temperatures between adults with and without PI diagnoses living in the same household.

Methods:

Patients with PI designed and launched a cohort comparison study. With the help of a multidisciplinary team and the IDF, a patient-informed study came to fruition with patient-driven input at every step of the way. Initial screening questionnaires were used to select participants. Median body temperatures were compared between the two cohorts at each time point using Mann-Whitney test. Prism 6.0 was used to perform statistical analyses. A post-study patient experience survey was conducted by IDF to encourage feedback at the conclusion of the study.

Results:

Data from 254 households were used for analysis (72.6% participation rate). The PI population was predominantly female (85.8%), Caucasian (97.6%), and with a median age of 49 years. The non-PI population was largely male (66.9%), Caucasian (92.9%), and with a median age of 53 years. Common variable immunodeficiency was the most common PI diagnosis (74.8%). 123 individuals with PI (48.4%) reported a “lower than normal” non-sick body temperature, while 108 individuals with PI (42.5%) reported a “normal (between 97°F - 99°F)” non-sick body temperature. A total of 172 individuals with PI (67.7%) reported absence of fever with infection, while 50 individuals (19.7%) reported a normal fever response with infection. Objectively, the median body temperature was significantly higher for PI patients in the morning, but not evening or bedtime, in 4 of 5 days. The median temperatures did not differ significantly at any other time point or day during the study. Although 22.4% of PI patients self-reported being sick during the study period, a fever of 100.4°F or higher in PI subjects was uncommon, occurring only twice during the study period, while 77.2% had a normal temperature (between 97°F - 99°F) and 16.2% had a lower than normal temperature (between 95.0-96.9°F) when sick. According to the post-study questionnaire, 91% (n=61) of survey participants (n=67) indicated that it would also be “very likely” that they would participate in future IDF research studies, even though 94% (n=62) of participants had never taken part in prior studies.

Conclusions:

To our knowledge, this is the first study to evaluate average body temperature in individuals with PI. Compared to non-PI controls, individuals with PI appear to have higher median body temperatures in the morning. When sick, median temperatures in individuals with PI may be higher mid-week, without mounting a complete fever response of 100.4°F. More research is needed to understand the mechanisms behind this difference, and to determine if this baseline temperature difference is attributable to immune dysregulation. This study highlights that individuals with PI are knowledgeable about their health and can offer unique insights and direction to researchers and clinicians in patient-driven research at every step of the research process.