Table 1.

Cerebrospinal fluid (CSF), serological and microbiological findings in the 2 patients with IgG4 hypertrophic pachymeningitis.

APatient 1Patient 2
Reference ValuesBefore TherapyAfter TherapyBefore TherapyAfter Therapy
AppearanceColorless, clearColorless, clearColorless, clearColorless, clearColorless, clear
Total proteins (mg/dl)12–6076764473
Glucose (mg/dl)40–8042555956
Cells (μl)0–132 (lymphocytes)20 (lymphocytes)2 (lymphocytes)1 (lymphocytes)
Cytological analysisNo atypical cellsNo atypical cellsNo atypical cellsNo atypical cells
Microbiological analyses*NegativeNegativeNegativeNegativeNegative
Autoimmunity and ACE§NegativeNegativeNegative
CSF albumin (mg/dl)10–3085452537
Serum albumin (mg/dl)3500–50002370265033504180
Albumin Quotient^< 0.73.61.70.70.9
CSF IgG (mg/dl)0.8–3.817.45.88.73.5
Serum IgG (mg/dl)840–1600607797651736
IgG Index< 0.700.840.431.80.53
IgGLoc0105.50
CSF IgG4 (mg/dl) °0.01–0.325.350.074.940.54
Serum IgG (mg/dl)3–230461921075
IgG4 Index°0.25–0.913.210.233.160.81
IgG4Loc04.103.910.09
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  • A. *PCR for Herpes simplex virus types 1 and 2, varicella-zoster virus, cytomegalovirus, Epstein-Barr virus, enterovirus, Mycobacterium tuberculosis; gram, acid-fast stain, and microbiological cultures; search for Aspergillus fumigatus and Cryptococcus neoformans antigens; serology for Lyme disease, brucellosis, syphilis.

  • § Rheumatoid factor, antinuclear, anticyclic citrullinated peptide, and antineutrophil cytoplasmic antibodies; angiotensin converting enzyme (ACE).

  • ^ Albumin quotient measures the blood-CSF barrier permeability.

  • ° Normal range for CSF IgG4 concentration and IgG4 Index was calculated using 9 patients affected by pituitary nonsecreting adenomas without blood-CSF barrier damage and OCB on CSF analysis, nor evidence of meningitis on magnetic resonance imaging. IgG4-HP: immunoglobulin G4-related hypertrophic pachymeningitis.

  • B. Cerebrospinal fluid concentration of IgG subclasses (IgG1, IgG2, IgG3, and IgG4) show a significant decline after immunosuppressive treatment of IgG4 levels in both patients, as well as of IgG1 levels in Patient 1. IgG2 and IgG3 were not significantly affected by immunosuppressive therapy.