Cerebrospinal Fluid Analysis in Immunoglobulin G4-related Hypertrophic Pachymeningitis

Abstract

To the Editor: Immunoglobulin G4-related disease (IgG4-RD) is characterized by fibrous swelling of affected organs, elevations in serum IgG4 concentrations, and responsiveness to glucocorticoid treatment1. Affected tissues display similar histological features: diffuse lymphoplasmacytic infiltration by numerous IgG4-positive plasma cells, occasional eosinophils, storiform fibrosis, and obliterative phlebitis2. IgG4-related hypertrophic pachymeningitis (IgG4-HP) has been identified as a characteristic central nervous system (CNS) manifestation of IgG4-RD, but comprehensive cerebrospinal fluid (CSF) analyses are substantially lacking3,4. Recently, we demonstrated an intrathecal IgG and IgG4 synthesis in the CSF of a patient with IgG4-HP and suggested IgG4 Indices as safe potential diagnostic tools for IgG4-HP5. Here, we describe 2 new cases of IgG4-HP with CSF evaluation at diagnosis and in response to treatment. In case 1, March 2007, a 56-year-old man was admitted with a 1-year history of right frontal headache. Magnetic resonance imaging (MRI) showed right frontal pachymeningitis. Granulomatous meningeal inflammation was suspected and oral prednisone (1 mg/kg body weight/day) was started with clinical and radiological improvement. Prednisone was discontinued after 8 months, but in July 2008 the headache recurred. Blood and CSF analyses are shown in Table 1. MRI evidenced a right frontotemporal progression of the pachymeningitis (Figure 1A). A meningeal biopsy … Address correspondence to Dr. E. Della-Torre, Department of Medicine and Clinical Immunology, San Raffaele Scientific Institute, Via Olgettina 60, 20132, Milan, Italy. E-mail: dellatorre.emanuel{at}hsr.it