Impact of multi-drug resistant organisms after stem cell transplantation

This study examined the impact of multi-drug resistant organisms in patients who had undergone stem cell treatment. The study concluded that patients colonized with multi-drug resistant organisms should be watched closely for infections after transplantation. 

Stem cell transplantation is a treatment used in multiple myeloma, lymphoma, and leukemia. In autologous stem cell transplantation (autoSCT), the stem cells are harvested from the patient. Before autoSCT, patients must receive high doses of chemotherapy. High dose chemotherapy suppresses the immune system, causing patients to be easily susceptible to infections. 

Some patients are colonized with multi-drug resistant organisms (MDRO), where certain bacteria are present on the body. These MDRO are able to resist treatment from multiple drugs. MDRO include vancomycin-resistant enterococcus (VRE), MRSA and multidrug-resistant gram-negative bacteria. It is not clear what the impact of colonization with MDRO has on patients after autoSCT.  

184 patients who had an autoSCT were studied. Of 184 patients in the study, 21.7% were colonized by MDRO. 72.5% of patients with lymphoma and 25.5% of patients with multiple myeloma were colonized with MDRO.

After an average 21.5 months of follow-up, the estimated overall survival (time from treatment until death from any cause) was 70.9%. The overall survival of patients who were colonized was 61.7%. The overall survival of patients who were not colonized was 73.3%. Among patients with MDRO colonization, those with VRE had an overall survival of 53.5%. This difference in survival between colonized patients and non-colonized patients was found in patients with lymphomas, but not in patients with myelomas.  

Colonization with MDRO was associated with a 2.46 times increased risk of death. Overall, the average time to worsening disease was 49.7 months. There was no significant difference in time to worsening disease between patients who were MDRO colonized and patients who were not. 

The authors concluded that patients with MDRO colonization had a worse overall survival after stem cell transplantation than patients without MDRO colonization. They suggested these patients should be closely watched for signs of infection.