This is a patient who had last been seen four months previously. She had tapered off steroids since that time, and her blood sugar was better controlled. She had not worsened or improved since stopping steroids. She remained on mycophenolate without side effects. The family asked about a trial of intravenous immunoglobulin (IVIG). Examination revealed impaired balance with positive Romberg sign, past pointing, dysdiadochokinesia, dysmetria, mildly slow left finger taps, axial ataxia, wide based gait with use of a cane and normal general appearance, counts/constitutional, eye, cranial nerve, motor, reflex, sensory, and sensory examinations. Diagnoses were Hashimoto encephalopathy, ataxia, and abnormal gait. It was noted that there had been a five year lag between the onset of symptoms and treatment, and provider does not believe that she could improve further. A course of IVIG was requested.
A prior authorization request dated indicated a request for intravenous immunoglobulin for a diagnosis of Hashimoto encephalopathy.
A specialty immunoglobulins (IG) enrollment form indicated a request for IVIG for Hashimoto encephalopathy for home infusions.
An IVIG prescription indicated a request for IVIG for 20 grams (g) per day for five days every four weeks for three months.
A letter of medical necessity indicates that the patient has a diagnosis of Hashimoto encephalitis, with anti-glutamine acid decarboxylase (anti-GAD) antibodies. This has been treated with prednisone and mycophenolate, with impaired glycemic control due to the prednisone. She had not worsened on the medication but had not improved with regard to ataxia and balance. An initial three month course of IVIG was requested. The health plan's determination is upheld. This is a patient with diagnosis of Hashimoto encephalitis, with anti-glutamine acid the carboxylase (gag) antibodies.
There is no evidence, based on clinical data from prospective clinical trials, that IVIG is effective in the treatment of Hashimoto's encephalitis. A review of current peer-reviewed medical literature fails to reveal any prospective trials supporting its efficacy. There have been no randomized placebo-controlled prospective trials providing definitive evidence of efficacy. There have been no prospective open label trials supporting efficacy. All medical evidence is based on case reports or retrospective analyses. Case reports and retrospective analyses cannot support efficacy of any treatment, as non-effective treatments tend not to be reported.
Therefore, in the absence of any evidence of efficacy in the peer-reviewed medical literature, the use of IVIG in the form of Gamunex-C is not medically necessary for this patient.