Background: Because of its reported similarities to Sydenham chorea, therapeutic plasma apheresis (TPA) has been proposed as a potential treatment of pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS). To date, support for the use of TPA has been limited to a few anecdotal reports and a small placebo-controlled trial demonstrating dramatic symptom improvements at 1 month and 1 year follow-up. To evaluate the safety and efficacy of TPA further, we undertook a retrospective review of all PANDAS patients treated with TPA at Georgetown University Hospital between August 2009 and October 2013.
Methods: Forty patients were identified, and sufficient information was available from medical records and telephone interview for 35 cases (88%). All 35 (23 boys; 12 girls) met diagnostic criteria for PANDAS (Swedo et al. 1998 ) and had severe symptoms. The TPA procedures were performed at Georgetown University Hospital using a protocol that processes a total of 4.5 blood volumes over 3-5 days (three treatments of 1.5 volumes each). Overall symptom improvements at 6 months post-TPA and long-term follow-up were estimated by parents, who also rated changes in individual symptoms to provide information about patterns of improvement.
Results: All patients were reported to have received at least some benefit from TPA, with average improvement of 65% at 6 months post-TPA and 78% at longer-term follow-up. A decrease in the number of reported symptoms also occurred, with particular improvements in obsessive-compulsive disorder (OCD), anxiety, tics, and somatic symptoms, including dysgraphia, sleep difficulties, and urinary urgency or frequency. Contrary to expectations, preceding duration of illness was not correlated with degree of improvement following TPA, suggesting that acuity of illness is not a factor affecting response. Only two adverse events were reported: both involved reopening of the site where the central line had been placed and resolved immediately following application of pressure and re-dressing of the puncture site.
Conclusions: Therapeutic plasma apheresis is an invasive medical intervention that should be reserved for treatment of children and adolescents who are severely affected by PANDAS. In such patients, it appears to be a safe, well-tolerated, and beneficial treatment option.