title: Macrophage clustering as a diagnostic marker in sural nerve biopsies of patients with CIDP.
abstract: BACKGROUND
  In adult patients with a slowly progressive demyelinating neuropathy, it may be difficult to distinguish between a hereditary neuropathy and chronic inflammatory demyelinating polyneuropathy (CIDP). The authors previously observed clustering of macrophages around endoneurial blood vessels in sural nerve biopsies from patients with CIDP.
  
  
  OBJECTIVE
  To quantitate macrophage clustering around endoneurial blood vessels in CIDP vs hereditary neuropathies.
  
  
  METHODS
  The authors studied 21 patients with CIDP, 18 patients with hereditary neuropathies, and 5 normal sural nerves. Numbers of macrophages, T-cells, and blood vessels were counted after immunohistochemical staining. The presence of three or more macrophages around one blood vessel was defined as a cluster. In a subsequent validation analysis, 65 stored biopsy specimens obtained from patients with a chronic neuropathy were re-evaluated for perivascular macrophage clustering according to criteria derived from the quantitative analysis of the first 221 biopsies in a blinded fashion.
  
  
  RESULTS
  The percentage of endoneurial vessels with macrophage clusters was higher in CIDP than in hereditary neuropathies (CIDP median = 9.4, range 0 to 48; hereditary NP median = 0, range 0 to 7.7; p < 0.001). The evaluation of the 65 further biopsies showed that the presence of one perivascular macrophage cluster per fascicle proved to be a valid criterion to differentiate between inflammatory and other forms of neuropathy (chi2 test p = 0.0000025, sensitivity 75%, specificity 72%).
  
  
  CONCLUSIONS
  The presence of clusters of macrophages around endoneurial vessels in sural nerve biopsies may serve as a useful additional marker for establishing the pathologic diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP).
authors.affiliation: Department of Neurology, Julius-Maximilians Universität, Würzburg, Germany. sommer@mail.uni-wuerzburg.de
authors.forename: C
authors.initials: C
authors.lastname: Sommer
authors.forename: S
authors.initials: S
authors.lastname: Koch
authors.forename: M
authors.initials: M
authors.lastname: Lammens
authors.forename: A
authors.initials: A
authors.lastname: Gabreels-Festen
authors.forename: G
authors.initials: G
authors.lastname: Stoll
authors.forename: K V
authors.initials: KV
authors.lastname: Toyka
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers; D001706:Biopsy; D001808:Blood Vessels / Q000276:immunology / Q000473:pathology / Q000503:physiopathology; D003937:Diagnosis, Differential; D005260:Female; D009477:Hereditary Sensory and Autonomic Neuropathies / Q000175:diagnosis; D006801:Humans; D008264:Macrophages / Q000276:immunology / Q000473:pathology*; D008297:Male; D008833:Microcirculation / Q000276:immunology / Q000473:pathology / Q000503:physiopathology; D008875:Middle Aged; D015588:Observer Variation; D010525:Peripheral Nerves / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology; D020277:Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / Q000175:diagnosis* / Q000276:immunology / Q000503:physiopathology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013497:Sural Nerve / Q000098:blood supply / Q000473:pathology* / Q000503:physiopathology*
chemical_list: D015415:Biomarkers