In those with a history of anti-NMDA encephalitis with identified teratoma s/p resection and clinical symptom improvement, is there a role for monitoring anti-NMDA antibody titer as a marker of disease recurrence?  

This has been extensively answered in the literature. The paper of Gresa-Arribas et al., PMID 24360484 in Lancet Neurol 2014 answers the question. "In the current study, the importance of CSF antibody titers is demonstrated in patients with clinical relapses in whom the fluctuation of CSF titer...