Oligoclonal immune response in cerebral cavernous malformations. Laboratory investigation.
OBJECTIVE
Mechanisms of cerebral cavernous malformation (CCM) pathogenesis include genetic predisposition in some cases, but other factors are likely to be involved in lesion proliferation and clinical manifestations. Given the unique antigenic milieu of CCMs, there may be a characteristic immune response in these lesions. We hypothesize that the immunoglobulin (Ig) fraction in CCMs reflects an oligoclonal immune response not present in paired sera from the same patients or in other types of cerebrovascular malformations.


METHODS
Surgically excised lesions from five patients with CCMs, three patients with arteriovenous malformations (AVMs), and four normal brain control specimens obtained at autopsy were homogenized and extract tested for IgG clonality by isoelectric focusing in parallel with each patient's serum.


RESULTS
The authors detected B cells in all three lesions examined, and plasmacytes in two out of three lesions examined. Four of five extracts of homogenized CCMs showed an oligoclonal pattern of IgG distinct from the polyclonal pattern seen in those patients' sera. Immununoglobulin G oligoclonality was not seen in AVMs or control brain specimens.


CONCLUSIONS
The results of isoelectric focusing studies showed that CCM lesions had oligoclonal patterns of IgG unrelated to peripheral blood contamination, indicating selective synthesis of IgG within the lesions. This finding probably reflects a clonal expansion of B cells and/or plasmacytes in CCMs, an event that might be antigen-driven or a potential marker of inflammation.
Shi
Changbin
C
Department of Neurological Surgery, Evanston Northwestern Healthcare, Illinois 60201, USA.
Shenkar
Robert
R
Batjer
H Hunt
HH
Check
Irene J
IJ
Awad
Issam A
IA
D001402:B-Lymphocytes / Q000276:immunology / Q000473:pathology; D001921:Brain / Q000276:immunology / Q000473:pathology; D001932:Brain Neoplasms / Q000276:immunology* / Q000473:pathology; D020786:Hemangioma, Cavernous, Central Nervous System / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D002538:Intracranial Arteriovenous Malformations / Q000276:immunology; D043025:Oligoclonal Bands / Q000032:analysis*; D010950:Plasma Cells / Q000276:immunology / Q000473:pathology
D043025:Oligoclonal Bands