Expression of cerebellar degeneration-related proteins CDR2 and CDR2L in human and rat brain tissue.

Patients with ovarian cancer and paraneoplastic cerebellar degeneration, a cancer-related immune disorder, often have anti-Yo antibody. Here we studied the distributions of anti-Yo antigens CDR2L and CDR2 in rat and human brain using immunohistochemistry and western blot. CDR2L localized mainly to the Purkinje cells and large neurons scattered in the brain stem. CDR2 was detected in vascular smooth muscle cells of rat and human and in cells lining the ventricle system in rats. The observed distribution of CDR2L is compatible with the hypothesis that this antigen is the major target of anti-Yo. CDR2 and CDR2L are expressed by different cell subtypes.

CDR2L Is the Major Yo Antibody Target in Paraneoplastic Cerebellar Degeneration.

The pathogenesis of Yo-mediated paraneoplastic cerebellar degeneration (PCD) is unclear. We applied cerebrospinal fluid and serum from PCD patients as well as CDR2 and CDR2L antibodies to neuronal tissue, cancer cell lines, and cells transfected with recombinant CDR2 and CDR2L to elucidate which is the major antigen of Yo antibodies. We found that Yo antibodies bound endogenous CDR2L, but not endogenous CDR2. However, Yo antibodies can bind the recombinant CDR2 protein used in routine clinical testing for these antibodies. Because Yo antibodies only bind endogenous CDR2L, we conclude that CDR2L is the major antigen of Yo antibodies in PCD. ANN NEUROL 2019;86:316-321.

Cerebellar degeneration-related proteins 2 and 2-like are present in ovarian cancer in patients with and without Yo antibodies.

BACKGROUND: Cerebellar degeneration-related protein 2 (CDR2) has been presumed to be the main antigen for the onconeural antibody Yo, which is strongly associated with ovarian cancer and paraneoplastic cerebellar degeneration (PCD). Recent data show that Yo antibodies also target the CDR2-like protein (CDR2L). We, therefore, examined the expression of CDR2 and CDR2L in ovarian cancer tissue from patients with and without Yo antibodies and from various other cancerous and normal human tissues. METHODS: Ovarian cancer tissue and serum samples from 16 patients were included in the study (four with anti-Yo and PCD, two with anti-Yo without PCD, five with only CDR2L antibodies, and five without onconeural antibodies). Clinical data were available for all patients. The human tissues were examined by western blot and immunohistochemistry using rabbit CDR2 and CDR2L antibodies. RESULTS: Ovarian cancers from all 16 patients expressed CDR2 and CDR2L proteins. Both proteins were also present in normal and cancer tissue from mammary tissue, kidney, ovary, prostate, and testis. CONCLUSION: CDR2L is present in ovarian cancers from patients with and without Yo antibodies as was shown previously for CDR2. In addition, both CDR2 and CDR2L proteins are more widely expressed than previously thought, both in normal and cancerous tissues.

Paraneoplastic neurological syndromes in lung cancer patients with or without onconeural antibodies.

BACKGROUND: Paraneoplastic neurological syndromes (PNS) are poorly described in patients without onconeural antibodies and in patients with non-small cell lung cancer (NSCLC). We compared the clinical characteristics of PNS in lung cancer patients with and without onconeural antibodies. METHODS: Medical records from patients with lung cancer and neurological symptoms referred for onconeural antibody analysis in the period 1995-2004 were analyzed and well-established diagnostic criteria used for the retrospective diagnosis of PNS. Thirty-one patients were diagnosed with PNS and included in the study. Data from the Cancer Registry of Norway and follow-up medical data were analyzed. RESULTS: Small-cell lung cancer (SCLC) was the most common lung cancer in the 31 PNS patients (77%, P<0.01). Onconeural antibodies were found in 18 of the PNS patients (58%). Paraneoplastic encephalomyelitis (PEM) was the most common PNS among the seropositive patients (11 of 18 patients), of which 10 had SCLC. Various types of PNS were found in the 13 seronegative patients. CONCLUSION: Approximately 40% of PNS patients with lung cancer do not have onconeural antibodies. PEM was the most common PNS in the seropositive patients. Our results underline the importance of recognizing PNS in patients with NSCLC and those without onconeural antibodies.