Association between oral ulcerative lesions, oral infections, and fever during the pre-engraftment phase after hematopoietic cell transplantation: results from the Orastem study

Abstract Purpose The percentage of cases with fever of unknown origin after hematopoietic cell transplantation (HCT) is high. An often overlooked clinical infection in HCT recipients may be chronic inflammation from the oral cavity. Therefore, the aim of the present study was to assess fever in the pre-engraftment phase after HCT and to examine the relationship between oral foci of infection before and in the first weeks after HCT and fever. Methods Adult patients, scheduled for autologous or allogeneic HCT, were included in this prospective, observational multicenter cohort study. Oral health was determined pre-HCT. Following HCT conditioning, fever was registered daily; and oral mucositis and other oral side effects were registered three times weekly. Results Data from 186 patients were available. The mean age was 53.0 years (± 12.9), and 55.4% were male. The most common malignancies were multiple myeloma, acute myeloid leukemia, and lymphoma. In total, 69.4% of the patients developed fever and 43.1% had an oral ulcerative lesion. After correction for age, site, conditioning regimen, diarrhea, vomiting, and duration of leukopenia, oral ulceration size remained significantly associated with fever, especially when fever was defined as ≥ 38.5°C. Pre-HCT chronic dental and oral conditions showed no association with post-HCT fever. Conclusion Fever was common during the pre-engraftment phase after HCT and significantly associated with the extent of oral ulcerations. In contrast, pre-HCT dental and oral conditions showed no association with post-HCT fever, highlighting the specific role of mucosal injury in febrile episodes.