Sensitivity of Coccidioides serologic tests among culture-proven coccidioidomycosis patients with hematological malignancy compared to a matched immunocompetent cohort.

Abstract

Coccidioidomycosis is associated with an increased risk of mortality and morbidity among immunosuppressed patients. The sensitivity of current commercial Coccidioides serologic tests is not well evaluated in patients with hematological malignancy. We conducted a retrospective study, including patients with culture-proven coccidioidomycosis, from October 1, 2017, to December 12, 2023. Cases with hematological malignancy and hematopoietic stem cell transplant (HM) were matched with an immunocompetent cohort (1:2) to compare the sensitivity of serology (enzyme immunoassay IgG/IgM or Complement Fixation) tests-matched by age, gender, and race. We matched 43 HM patients with 86 controls. The median age of the HM/HSCT cohort was 67 (IQR, 52 - 75), 65% male, and 86% White. Most HM had lymphoma (37%), followed by leukemia (35%). Most cases had pulmonary infection (74%) vs. controls (84%), p-value=0.2, and 12% had a prior history of coccidioidomycosis compared to controls (17%), p-value=0.4. Positive Coccidioides serology test results among HM were statistically significantly lower than controls (37% vs. 72%), p-value≤0.001. Multivariate conditional logistic regression identified HM and a history of coccidioidomycosis were statistically significantly associated with positive serologic testing, with OR 0.27 (95% CI 0.12 - 0.62, p-value= 0.002) and OR 6.07 (95% CI 1.25 - 29.4, p-value= 0.025), respectively. Coccidioides serology tests in HM patients with culture-proven coccidioidomycosis had low sensitivity. Given the increased risk of complications in this group, future studies are needed to evaluate more sensitive diagnostic tests.