Ki Lam¹, Ricky Ip¹, Jervis Leung¹, Sally Wong¹, Elaine Au¹

Division of Immunology, Department of Pathology, Queen Mary Hospital

 

Onconeural antibodies were named as they were known to be associated with malignancies^1,2. They could present as various combinations of central and peripheral nervous system dysfunction. However, recently there were controversial view on their malignancy associations^1-3. 

 

We reviewed our positive cases for onconeural antibodies since the introduction of the tests (14 years in total; 2008-2021). All patients with positive onconeural antibody detection by indirect immunofluorescence (IIF) and immunoblots (IB) were included. 

Among the 51 patients who were identified with positive paraneoplastic antibodies, the majority had either anti-Hu (n=21; 21/51=41.1%) or anti-Yo or other anti-Purkinje cell antibodies (n=13; 13/51=25.5%). Anti-Ma/Ta (n=6; 6/51=11.8%), anti-amphiphysin (n=5; 5/51=9.8%) and anti-Ri (n=4; 4/51=7.8%) antibodies followed. One patient was diagnosed with a positive anti-GFAP antibody. Overall, 58.8% (30/51) of patients with positive paraneoplastic antibodies were associated with malignancies, with the highest rate in anti-Hu positivity (n=15; 15/21= 71.4%). Among the patients with either anti-Yo or other anti-Purkinje cell antibody, anti-amphiphysin, and anti-Ma/Ta positivity, 50-61.5% associated with malignancies. Only 25% (1/4) of patients with anti-Ri had a history of cancer. Concordant with literature, the most common tumor associated with anti-Hu was small cell lung carcinoma (n=10; 10/15=66.7%), while that for anti-Yo or other Purkinje cell antibodies were gynaecological malignancies (n=5; 5/8= 62.6%). 

 

Despite the presence of onconeural antibodies not necessarily indicating malignancies, meticulous screening for underlying tumors is crucial to facilitate patient management.

 

1.      Giometto, Bruno, et al. "Paraneoplastic neurologic syndrome in the PNS Euronetwork database: a European study from 20 centers." Archives of neurology 67.3 (2010): 330-335.

2.      Karim, A., W. Egner, and D. Patel. "International consensus: paraneoplastic neurological antibodies—are we there yet." J Clin Exp Neuroimmunol 1.1 (2016).

3.      Budhram, Adrian, Michael W. Nicolle, and Liju Yang. "The positive predictive value of onconeural antibody testing: a retrospective review." Canadian Journal of Neurological Sciences 45.5 (2018): 577-579.

 

The laboratory tests (onconeural antibodies by indirect immunofluorescence (IIF) and immunoblots (IB)) was performed in Immunology lab, Department of Pathology, Queen Mary Hospital, Hong Kong.

 

All the authors were involved in the interpretation and analysis of the test results.