Abstract Details

MP is a common bacterial pathogen often eliciting mild respiratory symptoms. Prevalence within the community ranges from 2-35%. MP has been linked to immune-mediated Guillain-Barré syndrome through proposed molecular mimicry. Along the same line, we propose a relationship between MP and other autoimmune disorders resulting in POTS and/or SFN.

To demonstrate an increased prevalence of Mycoplasma pneumoniae (MP) infection in subjects with autoimmune disorders, Small Fiber Neuropathy (SFN) and/or POTS.

This is a retrospective cohort study of patients presenting to our autonomic center with symptoms suggestive of an autonomic nervous system dysfunction, who underwent autonomic testing and etiological investigation. We analyzed those patients on whom we reached a diagnosis of autoimmune disorder including Hashimoto Thyroiditis, Sjögren’s syndrome, or other autoimmune disorders, for the presence or absence of MP infection. MP IgG >320 units/ml is defined as definite infection while values between 100 and 320 units/ml are defined as likely or remote infection. 

Secondarily, we analyzed the percentage of MP infection in patients who were found to have POTS or SFN. 

MP serologic testing results were analyzed on 51 patients with one or more of the above-mentioned autoimmune disorders. MP IgG >320,  >100, and <100 units/ml were found in 30 (59%), 43 (84%), and 8 (16%) of all patients, respectively.  Thirty six patients were diagnosed with SFN (71%), of which 30 (83%) had IgG >100 and 20 (56%) had IgG >320. Twenty patients were diagnosed with POTS (39%) out of whom 17 (85%) had IgG >100 and 14 (70%) had IgG >320.

Highly elevated MP titers are present in a large majority of patients with autoimmune disorders and in co-occurring SFN or POTS, compared to their published prevalence in the general population. Further research is needed to determine whether this is a causative effect or an association due to molecular mimicry.