Immunotherapy with subcutaneous immunoglobulin or plasmapheresis in patients with [POTS], Blitshteyn et al, 2022

Background

Postural orthostatic tachycardia syndrome (POTS), one of the most common autonomic disorders, is associated with significant morbidity and functional impairment. Although several possible etiologies have been proposed, autoimmunity has emerged as one of the leading causes with various specific and non-specific antibodies identified in patients with POTS. Treatment with intravenous immunoglobulin has been previously described.

We present a case series of patients with severe POTS refractory to the standard pharmacologic and non-pharmacologic therapies treated with immunotherapy consisting of either subcutaneous immunoglobulin (SCIG) therapy or plasmapheresis (PLEX) and report their treatment outcomes.

Methods

Clinical history of 7 patients with POTS who were treated with SCIG or PLEX was reviewed. Response to treatment was assessed using COMPASS 31 and functional ability scale (FAS), completed by patients retrospectively, pre- and 3–12 months post-treatment with SCIG or PLEX.

Results

All patients improved following SCIG or PLEX with an average 50% reduction in COMPASS 31 score and 217% increase in FAS scores. Six out of seven patients were able to reduce or discontinue oral medications for POTS, and five patients were able to return to work or school. Four patients had skin biopsy or quantitative sudomotor axon reflex test (QSART)-proven small fiber neuropathy, and five had various positive antibodies at low titers.

Conclusion

Patients with severe, treatment-refractory POTS experienced significant functional improvement with reduction in the autonomic symptoms following immunotherapy with SCIG or PLEX. Randomized controlled trials of SCIG and/or PLEX are needed to determine the efficacy and safety of these long-term therapies in patients with POTS.

https://link.springer.com/article/10.1007/s00415-022-11344-z

Author-provided access to the paper: https://nam12.safelinks.protection....CTlDRdMtYbm/dAB63k5hC/XGXzju2qbqM=&reserved=0

 

I am perplexed by the absence of objective measures, such as heart rate during an active standing test, in a study done at a tertiary clinic specialized in dysautonomia.

 

I wholeheartedly agree. Serious researchers should avoid repeating the mistakes of BPS studies. A NASA lean test takes, what, 10 minutes? I'm happy they recorded some basic objective outcomes. 6/7 could reduce/stop medication and 5/7 returned to work? That's pretty impressive, but maybe they cherry-picked those numbers. The paper seems convincing that we need RCTs but I feel like I'm missing something.

 

The author's access states that 'unfortunately due to financial reasons' on these not happenning to provide objective data. I wonder whether they maybe hoped that providing the case studies could in itself be a bid to fund 7 tests along these lines.

I don't know whether the NASA Lean test even requires a certain type of expertise however (given this seems the alternative that doesn't have the cost issues) and what the issue re: data gaps would have been in these, and why they weren't done?