RT Journal Article SR Electronic T1 Acute acalculous cholecystitis JF Neurology JO Neurology FD Lippincott Williams & Wilkins SP e1548 OP e1552 DO 10.1212/WNL.0000000000005422 VO 90 IS 18 A1 David Croteau A1 Charlene Flowers A1 Corrinne G. Kulick A1 Allen Brinker A1 Cindy M. Kortepeter YR 2018 UL http://n.neurology.org/content/90/18/e1548.abstract AB Objective To evaluate acute acalculous cholecystitis (AAC) as a potential safety risk for patients treated with alemtuzumab.Methods The Food and Drug Administration Adverse Event Reporting System and the medical literature were searched for cases of AAC in conjunction with alemtuzumab for all clinical indications.Results Eight spontaneously reported cases meeting the case definition of AAC in close temporal association with alemtuzumab use were identified. Based on established criteria within the Food and Drug Administration Division of Pharmacovigilance for causality assessment, 4 cases were assessed as probable while 4 were possible. All cases occurred in patients with relapsing-remitting multiple sclerosis. Seven of the 8 cases presented with AAC during or shortly after alemtuzumab treatment, thereby suggesting an acute cytokine release syndrome as a putative pathogenic mechanism. The cases identified in this review differ from the typical AAC cases described in the medical literature based on female preponderance, lack of concurrent critical illnesses, inconsistent presence of other risk factors, and resolution with conservative treatment in the majority of cases.Conclusions AAC represents a new and potentially life-threatening adverse event associated with alemtuzumab use in relapsing-remitting multiple sclerosis. In cases seen to date, early and conservative treatment resulted in good clinical outcome, although the natural history of AAC in this population without critical illness is not well defined. Awareness of this safety risk by general and specialty neurologists is important for prompt recognition and optimal management.AAC=acute acalculous cholecystitis; ACRS=acute cytokine release syndrome; FAERS=Food and Drug Administration Adverse Event Reporting System; FDA=Food and Drug Administration; RRMS=relapsing-remitting multiple sclerosis