AGNA or SOX1 antibody is directed against the Bergmann glia of the Purkinje cell layer of cerebellum. It has been described in patients with PNS (usually Lambert Eaton myasthenic syndrome) associated with SCLC. The target for this antibody is SOX1 & SOX2 protein with higher positivity seen against SOX1.
Clinical case
Patient details
- 79yr old lady, admitted with right sided chest pain
- Weight loss over the past few months.
- Swallowing difficulties
Work-up
- A chest X-ray on admission revealed a right sided lesion
- CT thorax/abdomen revealed a large mass in the posterior mediastinum
- Extensive metastases noted within the chest and abdomen
If SOX1 antibodies are found, they are highly predictive of a small cell lung cancer and extensive tumour screening should be undertaken (including repeat imaging, PET scans etc.), even if the initial scans are apparently normal.