PS1554 CLINICAL PROFILE AND OUTCOMES IN PATIENTS RECEIVING CULTURE POSITIVE HEMATOPOIETIC STEM CELL HARVEST: RETROSPECTIVE STUDY FROM AN ONCOLOGY UNIT IN A TERTIARY CARE CENTER IN INDIA

Background: Hematopoietic stem cells (HSC) may act as a source of infection for the recipient due to manipulation at multiple levels from collection to infusion. Due to the high risk of contamination cultures are usually taken during multiple steps. The clinical significance of microbial contamination of HSC on the post‐transplant course and the role of prophylactic antibiotics is relatively unknown. Aims: The main objective of our study is to investigate the prevalence of microbial contamination of hematopoietic stem cell at our center and to assess its impact on the post‐transplant course. Methods: Records of all patients admitted in the bone marrow transplantation unit of a tertiary care center in India between January 2014 and December 2018 were analyzed after taking approval from the Institute's ethical committee. Clinical profile of patients including diagnosis, the indications of the transplant, conditioning regimen, details of cryopreservation, details of HSC culture and sensitivity were recorded. Details of episodes of febrile neutropenia including the day of onset, duration, number of febrile episodes, the focus of infection, use of prophylactic antibiotics, antibiotics administered, neutrophil engraftment, platelets engraftment were recorded. Results: Out of the 1307 stem cell harvests from 503 patients sent for culture, 17 harvests (1.3%) were found to have a culture positive report. Baseline characteristics of HSC culture‐positive patient are shown in Table 1. Sixteen of the seventeen patients had undergone autologous transplant. Multiple myeloma was most common indication of HSC transplant followed by Non‐Hodgkin Lymphoma (NHL). HSC harvests were cryopreserved in eight patients and duration of cryopreservation ranged from 7 to 34 days. Prophylactic ciprofloxacin, trimethoprim‐sulfamethoxazole, itraconazole, and acyclovir were used in all patient. Twelve of seventeen HSC cultures were positive at the time of infusion and five were positive at the time of harvest. The five HSC that were culture positive at the time of harvest were culture negative at the time of infusion. Gram‐positive organisms were isolated in six cultures and gram‐negative in rest. All patients developed febrile neutropenia post‐transplantation between day 1 and day 7. The median time of onset of fever was day +5 (1–7), the median duration of fever was 4 days (2–7), the median duration of antibiotic use was 11 days (9–16). Empiric treatment for febrile neutropenia in 13 out of 17 patients also covered for the organism grown in the HSC culture. Eight of these patients responded appropriately to the initial treatment while nine patient required the addition of other antibiotics. Only one patient had blood culture positivity post‐transplant and culture yielded the same organism as HSC culture. Median day for neutrophil engraftment was 11 days (9–16), the median day for platelet engraftment was 14 days (8–25) and median day for the duration of hospitalization was 15 days (12–78). All patients were alive at day 100 of transplant. Two patient which had prolonged stay, one had urinary tract infection post neutrophil engraftment; the second patient was the case of B‐ALL had acute GVHD, CMV colitis and VOD. Summary/Conclusion: Our study shows that there is no effect of culture‐positive HSC on transplant‐related outcomes in terms of the fever onset, duration of fever, neutrophil and platelet engraftment, duration of hospitalization and day 100 mortality. There is a need for larger prospective studies to understand the clinical relevance of such contaminations and the need for antibiotic prophylaxis in such cases.