title: Assessment of free light chains in the cerebrospinal fluid of patients with lymphomatous meningitis - a pilot study.
abstract: BACKGROUND
  Lymphomatous meningitis (LM) represents a severe complication of malignant lymphomas. While clinical suspicion is raised by symptoms ranging from mild disturbances of sensation to severe pain or impaired consciousness, the definite diagnosis of LM is often difficult to obtain. Since B-cell lymphomas are clonally restricted to express either kappa or lambda immunoglobulin light chain, we hypothesised that analysis of free light chain (FLC) ratios might facilitate the diagnosis of LM.
  
  
  METHODS
  Kappa and lambda FLC were measured using a novel nephelometric assay in cerebrospinal fluid (CSF) and serum from 17 patients. 5/17 suffered from LM as demonstrated by cytology, immunocytology, and/or imaging procedures.
  
  
  RESULTS
  Measurement of FLC concentrations in CSF was achieved for all 17 patients. FLC levels in CSF were lower than serum FLC levels in samples for the same patient obtained at the same time (p < 0.01). CSF and serum FLC concentrations correlated weakly in all patients irrespective of LM status. Significantly more patients with cytopathologically and immunohistochemically proven LM displayed abnormal kappa/lambda FLC ratios in CSF compared to individuals with no LM (p < 0.01).
  
  
  CONCLUSIONS
  This is the first report demonstrating that a significant proportion of LM patients display an abnormal kappa/lambda FLC ratio in the CSF.
authors.affiliation: Charité-Centrum für Tumormedizin, Medizinische Klinik mit Schwerpunkt Hämatologie und Onkologie, Campus Virchow-Klinikum, Charité- Universitätsmedizin Berlin, Augustenburger Platz 1, D-13344 Berlin, Germany. bert.hildebrandt@charite.de
authors.forename: B
authors.initials: B
authors.lastname: Hildebrandt
authors.forename: C
authors.initials: C
authors.lastname: Müller
authors.forename: A
authors.initials: A
authors.lastname: Pezzutto
authors.forename: Pt
authors.initials: P
authors.lastname: Daniel
authors.forename: B
authors.initials: B
authors.lastname: Dörken
authors.forename: C
authors.initials: C
authors.lastname: Scholz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000097:blood / Q000134:cerebrospinal fluid*; D005260:Female; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000097:blood / Q000134:cerebrospinal fluid*; D007146:Immunoglobulin lambda-Chains / Q000097:blood / Q000134:cerebrospinal fluid*; D008223:Lymphoma / Q000097:blood / Q000134:cerebrospinal fluid*; D008297:Male; D008581:Meningitis / Q000097:blood / Q000134:cerebrospinal fluid*; D008875:Middle Aged; D010865:Pilot Projects
chemical_list: D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains