Naltrexone therapy for Crohn's disease and ulcerative colitis

Intermittent blockade of OGFr and treatment of autoimmune disorders

IMPACT STATEMENT

This mini-review presents information on the intermittent blockade of the opioid growth factor (OGF)-OGF receptor (OGFr) axis by low-dose naltrexone (LDN), and the role of enkephalin (i.e. OGF) in autoimmune disorders, specifically multiple sclerosis, Crohn's, and fibromyalgia. Clinical reports on subjects taking LDN have documented reduced fatigue, few side-effects, and improved overall health. Preclinical studies on mice with experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis, revealed that immunization for EAE reduces serum OGF. Intermittent OGFr blockade with LDN restores serum enkephalin levels that correlate with reduced behavioral and pathological signs of EAE; LDN also increases enkephalin levels in naïve mice. The interplay between LDN, and the onset and treatment of autoimmune diseases, chronic pain, and other addictive behaviors requires further investigation, but highlights a central role for enkephalins and intermittent blockade of the OGF-OGFr pathway in pathogenesis and treatment of these disorders.

Low-dose Naltrexone for the treatment of sarcoidosis

Systemic therapy is administered to 50% of patients and the need for long-term use of therapy is quite variable (1,2). Prednisone is often administered for many months with risk for multiple side effects, immunomodulators as steroid sparing agents have a delayed onset of action and have risks for infection and malignancies, and infliximab increases the risk for infection (1). In light of these issues, alternative options for therapy are desirable. We made a comparison between sarcoidosis and Crohn's disease in that in each disease there is unregulated lymphocyte activity, a common unique pathological finding of non-caseating granulomas, and a similar approach to medical therapy (3,4). Low dose naltrexone (LDN) has been utilized for many conditions (5). Efficacy has been documented in Crohn's disease with randomized controlled studies showing mucosal healing and histologic improvement (6-7). LDN is compounded in 1/10^th to 1/20^th the dose used for the FDA-approved indications of narcotic and alcohol dependence (8). Neuropeptides (e.g., enkephalins and endorphins) are present in the gastrointestinal tract and endocrine cells and modulate immune responses (9). Up-regulation of met-enkephelin and opioid receptors can be induced by a rebound effect by short-acting LDN (10). Higher levels of endogenous opioids and receptors inhibit cell proliferation which suppress T and B lymphocyte responses (11,12) and decrease production of pro-inflammatory interleukins-6 and -12 (13). In light of the Crohn's disease LDN literature and similar experiences with other inflammatory conditions in our clinic (14,15), LDN was administered to a sarcoidosis patient with severe fatigue, sarcoid rash, and marked radiographic evidence of gastrointestinal involvement. (Sarcoidosis Vasc Diffuse Lung Dis 2017; 34: 184-187).