864. Therapeutic Immunosupression to Treat Rabies Encephalitis

BACKGROUND: Rabies is nearly universally fatal with about 60,000 annual deaths globally; <0.1% cases survive. Reports of therapeutic coma leading to survival are outnumbered by reports of failure. On the basis of personal discussions with a leading rabies expert (Dr Rodney Willoughby), we hypothesized that limiting CNS immune response based on CSF antibody titre (ABT) might prove useful. We report on successful use of immunosuppression in 1 patient. METHODS: A 26-year-old male was admitted with 2-day history of flu-like syndrome. He had category III dog bite on face 17 days prior. RIG was not given due to nonavailability; he had received ARV day 0, 3, 7, and 14 on time. On 4th day of admission (day 0), neurological features started—difficulty in walking and diplopia; hydrophobia was noted. Working diagnosis of rabies was made. MRI brain on day 1 showed subtle abnormal T2 and flair hyper intensities in pons, medulla, and left hippocampus. CSF (day 1) showed 105 cells; all lymphocytes. The RFFIT serum and CSF ABTs and rabies PCRs are tabulated below. Since ADEM was a possibility, he was begun on IVIg. Work up for other viral encephalitis was negative. Repeat CSF ABT on day 6 confirmed rabies. Postulating risk of death due to cerebral edema due to CNS immune response, dexamethasone (dexa) 6 mg/kg/day in 4 divided doses was begun on day 8. Serial MRI and CSF were done. Dexa taper was done based on MRI and CSF ABT. Intensive supportive care was given. RESULTS: MRI on day 9 and day 12 showed no cerebral edema. Dexa taper was started from day 13 by half every alternate day; it was given till day 28. By day 17, there was intermittent eye opening, withdrawal to pain and some orofacial and limb movements. Further recovery had waxing and waning course. Now he is nearly 1 year post rabies encephalitis. He is unable to talk or comprehend, but can sit independently and is able to walk with support. CONCLUSION: Immunosuppressive therapy with dexa to improve outcomes in rabies seems an exciting option. Optimal dose, time of start, and taper schedule need further studies. CSF ABT-based tapering appears promising. Larger studies with this approach are needed. [Image: see text] DISCLOSURES: All authors: No reported disclosures.