Basic haematology, kidney function, ionogram, liver function, C-reactive protein, TSHANA, ANCA, RF, erythrocyte sedimentation rate, complement, lupus anticoagulants, anti-cardiolipin antibodies, serum electrophoresis, ACE, sedimentation, anti-AQP4 antibodies, anti-MOG antibodies, HIV, HBV, HCV, toxoplasma serology, CMV serology, VZV serology, EBV serology, syphilis serology, Borrelia serology, tumour markers, JCV titre, IGRA testNeurofilament light protein. Here, AQP4 is linked to syphilis.