Discussion:
Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy, is a
recently described clinical entity presenting with aseptic meningitis
and a variety of neurological manifestations. It is a relatively new
addition to an ever-increasing list of autoimmune cerebellar ataxia
syndromes. it is defined by the presence of GFAP IgG in serum and CSF
which shows a similar pattern of immuno-florescence like AQP4 antibody
binding to pial and subpial astrocytes. (1)
Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy can
appear with other autoimmune diseases, systemic infections or as a
para-neoplastic disorder. (3,4,6) Many other antibodies including
NMDAR-IgG, AQP4-IgG, antinuclear, anti -endothelial cell, anti
-cardiolipin, anti -neutrophil cytoplasmic and anti -double -stranded
DNA can be found in serum of patients with GFAP astrocytopathy.(7)
30–40% of patients may have symptoms of systemic infection before the
onset of CNS manifestations. (3) Some patients develop the disorders
after Herpes Simplex type 1 or Varicella zoster viral infections.(8,9)
Our case also had a history of long-standing rheumatoid arthritis. In a
previously published case series of 22 patients with GFAP associated
syndrome, three subjects had coexisting rheumatoid arthritis. GFAP has
also been identified as an auto-antigen in the synovial fluid of
patients with RA. (10) Pachymeningitis in GFAP astrocytopathy has never
been reported before but can rarely be seen in long standing rheumatoid
arthritis.
Clinical symptoms in our case responded very well to oral steroids. Most
of the cases show rapid clinical and radiological improvements upon
starting corticosteroids with 20–50% of patients having relapsing
course requiring more prolonged therapy. (3,7,8,11,12) Prognosis varies
but is good with appropriate treatment in most of the cases. (2,13)