P-130: Diarrhea in multiple myeloma autologous stem cell transplant recipients: Think beyond mucositis!!

Introduction: Persistent diarrhea in Multiple myeloma patients undergoing Autologous transplant is related to conditioning regimen toxicity unless proven otherwise. However, we are observing an emerging rise in infectious complications in this setting and hence it is necessary to evaluate for the same to ensure better clinical outcomes.

Methods: This is an ambispective study of 2 years duration (2021-2023) conducted at Department of Hematology and Bone marrow transplant at a tertiary care hospital in Northen India. A total of 106 multiple myeloma patients underwent autologous transplant during the study period, out of which 84 patients (79.24%) were newly diagnosed multiple myeloma who attained Partial response (PR) or better response after first line treatment, while 22 patients (20.37%) were relapsed refractory myeloma patients after multiple lines of therapy. Patients were stratified based on age, co-morbidities, disease status, prior treatment and dose of melphalan used during conditioning. All patients who had diarrhea (by standard definition) for more than 2 weeks post -transplant were evaluated for alternative etiology (other than mucositis) by using both conventional and molecular techniques along with colonoscopy (wherever needed).

Results: Over the study period, out of the 106 patients included with median age of 62 years, 32 patients (30.19%) had persistent diarrhea. Twenty-nine of them (90.62%) had febrile neutropenia for which empiric/definitive antibiotics were given. Eight patients had Clostridium difficile toxins, 3 patients had Giardiasis, 1 patient had cryptosporidium oocysts detected on Stool routine analysis. Colonoscopy with biopsy and immunohistochemistry was performed in 18 out of the remaining 20 patients. CMV colitis was diagnosed in 6 patients, 2 patients had biopsy proven GVHD. Diarrhea in 12 patients was still attributable to mucositis after ruling out other etiologies. All the patients were treated as per standard treatment protocols including trial of steroids for the patients with GVHD. Successful resolution of diarrhea was achieved in 31 out of 32 patients.

Conclusions: In the current treatment era, melphalan related mucositis is still the most common cause of debilitating diarrhea. However, with newer diagnostic modalities and a collaborative team approach, other infectious /non-infectious etiologies are being increasingly recognized in this subgroup of patients. A careful analysis of the causative agents could lead to more accurate management, early intervention and prevention of serious complications.