Statistics from Altmetric.com
Editor,—The cause of Vogt–Koyanagi–Harada syndrome (VKH) is suspected to be systemic immunological reactions in various organs containing melanocytes.1-5 It has been suggested that the cell mediated immune process involving melanocytes plays an important role in the pathogenesis of VKH.1-5Supporting this idea, we previously reported the existence of melanin laden macrophages (MLMs) in the cerebrospinal fluid (CSF) of VKH patients.6 In clinical practice, as in our present case, detecting MLMs in CSF provides useful information on the activity of the patient’s systemic immunological reactions.
A 60 year old woman visited our hospital with blurred vision, tinnitus, and headache. Our first examination revealed that her best corrected visual acuity was 0.02 in the right eye and 0.01 in the left. Slit-lamp examination disclosed cellular infiltration in the anterior chamber and vitreous. Ophthalmoscopy showed serous retinal detachment with choroidal detachment in both eyes. Fluorescein angiography showed multifocal hyperfluorescent spots and diffuse subretinal pooling (Fig1). CSF examination revealed pleocytosis (cell counts 273 × 106/l) and a large number of MLMs (Fig 2). Following the diagnosis of VKH, we started the patient on intravenous prednisolone succinate 200 mg daily, gradually tapering the dose. Three months after the initial administration of corticosteroid, visual acuity recovered and the main clinical manifestations almost disappeared. At that time cell counts in the CSF had decreased (cell count 13 × 106/l) to within normal range, but MLMs were still present.
The dosage of corticosteroid was then decreased to 15 mg daily because no sign of recurrence was seen. After that, the patient developed fungal pneumonitis, which was successfully treated with antifungal agents for 3 weeks. Four months after the first attack, while MLMs did not disappear, she complained of blurred vision again. At that time her best corrected visual acuity decreased to 0.02 in the right eye and 0.01 in the left. Inflammation in the anterior chamber and serous retinal detachment recurred in both eyes.
We restarted the patient on corticosteroid therapy, using the same protocol as before. The main clinical manifestations disappeared in a month. The MLMs in the CSF finally disappeared 2 months after the second attack. Since then no recurrence has been noted even after corticosteroid therapy was reduced.
VKH is thought to be an autoimmune disease involving systemic melanocytes.15 Pleocytosis in VKH is considered a sign of the focal immune response against melanocytes in meninges.23 Although lymphocytes are predominantly observed in the CSF and uvea from patients with VKH,23 a small number of macrophages are also detected.4
In our previous report,6 we found melanin granules in the cytoplasm of macrophages in CFS obtained from VKH patients. In those patients MLMs were detected only in the early stage of the clinical course, and they disappeared after initial treatment. There was no recurrence of inflammation in those patients. In contrast, our present case showed the presence of MLMs for a long time, even though other clinical features, such as pleocytosis, had disappeared. It should be noted that there was a recurrence of VKH during the period when MLMs were detected in CSF and that no recurrence has been observed since the disappearance of MLMs in CSF. We suspect that the immune reaction against melanocytes is still present as long as MLMs are found, even though other clinical features were normal.
In clinical practice it is difficult to determine how to taper corticosteroid therapy to prevent recurrence. Detecting MLMs in a clinical course may indicate an immune reaction and also the prognosis of a patient.