RESUMO
Polymerase chain reaction (PCR) based automated high-resolution fragment analysis of rearranged immunoglobulin heavy-chain genes is a highly sensitive means for identifying clonal B-cell responses. We used this technique to distinguish polyclonal inflammatory from monoclonal neoplastic B-cell populations in the cerebrospinal fluid (CSF) of three patients with acute demyelinating disorders of the central nervous system whose clinical, magnetic resonance imaging (MRI) and CSF features did not permit unequivocal exclusion of primary central nervous system lymphoma (pC-NSL). This approach is highly suitable for detecting CNS inflammation particularly when lymphomatous involvement cannot be ruled out by noninvasive diagnostic procedures alone.
Assuntos
Neoplasias do Sistema Nervoso Central/líquido cefalorraquidiano , Neoplasias do Sistema Nervoso Central/genética , Doenças Desmielinizantes/líquido cefalorraquidiano , Doenças Desmielinizantes/genética , Linfoma/líquido cefalorraquidiano , Linfoma/genética , Doença Aguda , Adulto , Linfócitos B/citologia , Linfócitos B/fisiologia , Neoplasias do Sistema Nervoso Central/fisiopatologia , Regiões Determinantes de Complementaridade/líquido cefalorraquidiano , Regiões Determinantes de Complementaridade/genética , Regiões Determinantes de Complementaridade/fisiologia , Doenças Desmielinizantes/fisiopatologia , Eletroforese Capilar , Feminino , Humanos , Cadeias Pesadas de Imunoglobulinas/líquido cefalorraquidiano , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias Pesadas de Imunoglobulinas/fisiologia , Linfoma/fisiopatologia , Masculino , Reação em Cadeia da PolimeraseRESUMO
The diagnosis of leptomeningeal B-cell lymphoma is based on the identification of malignant B cells in the cerebrospinal fluid (CSF). Frequently, cytology does not allow clear distinction between neoplastic lymphoid cells and reactively transformed mononuclear cells. Individual B-cell clones can be identified on the basis of DNA sequences that encode the highly diverse complementarity-determining region (CDR3) of the immunoglobulin heavy chain locus (IgH). We studied CSF samples from 5 patients with B-cell malignancies and cytological evidence of leptomeningeal involvement, using polymerase chain reaction (PCR)-based high-resolution capillary electrophoresis and automated fluorescence analysis to detect PCR fragments. As controls, we assessed CSF specimens from 7 patients with inflammatory neurological diseases and three samples without pathological findings. In all patients with B-cell malignancies, a single PCR product was generated, indicating that CDR3-specific fragments were derived from monoclonal cell populations. CSF samples from patients with inflammatory diseases yielded multiple CDR3 amplicons, suggesting the presence of a polyclonal B-cell activation. No PCR product could be amplified in normal CSF samples. Automated fluorescence detection of CDR3 fragments is a highly sensitive and rapid method to distinguish neoplastic monoclonal and reactive polyclonal B-cell populations in the CSF.
