The realm of Pediatric Acute-onset Neuropsychiatric Syndrome (PANS) and Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections (PANDAS) is complex, and its interaction with autoimmunity becomes particularly significant in the unfolding narrative of the COVID-19 pandemic. The essence of these disorders lies in the immune system’s response, often triggered by infections, leading to neuropsychiatric symptoms in children. This blog aims to unravel the autoimmunity aspect of PANS and PANDAS, shedding light on the mechanisms underpinning these conditions, especially in the current health crisis dominated by COVID-19.
Autoimmunity is characterized by the immune system’s misguided attack on the body’s own cells. In PANS and PANDAS, this autoimmune response often arises following infections, notably streptococcal infections in the case of PANDAS, manifesting as various neuropsychiatric symptoms.
COVID-19 and its Role in PANS & PANDAS:
The COVID-19 pandemic has unveiled the significant impact systemic immune responses can have on neuropsychiatric conditions in children. The virus triggers an inflammatory and autoimmune response, leading to aberrant inflammation which, in turn, could induce neuropsychiatric abnormalities. This scenario is evidenced by heightened levels of pro-inflammatory cytokines like IL-6, IL-2, IL-17, and TNF that may compromise the blood-brain barrier and disrupt neurotransmission, thereby impacting the already disrupted basal ganglia GABAergic transmission in PANS and PANDAS.
Autoimmune Mechanisms in PANS and PANDAS:
These disorders are categorized under Idiopathic Autoimmune Encephalitis (IAE), wherein post-streptococcal autoimmunity manifests as neuropsychiatric symptoms such as obsessive rituals, tics, anxiety, and depression. The phenomenon of “molecular mimicry,” where host antibodies or lymphocytes become cross-reactive with both viral antigens and self-antigens, potentially initiating autoimmunity, becomes a significant pathophysiological mechanism.
The hallmark of these disorders is the sudden onset of obsessive-compulsive disorder (OCD) and/or tics, often accompanied by other behavioral symptoms, particularly following streptococcal infections. COVID-19 could act as a trigger for new onset or exacerbation of PANS/PANDAS symptoms, possibly through the reactivation of Epstein–Barr Virus (EBV), a known potential trigger for PANS.
Autoimmunity and Post-Infectious Syndromes:
PANS may manifest as a post infectious syndrome, representing a new form of postinfectious autoimmunity, further emphasizing the tight link between infections and the onset of neuropsychiatric symptoms.
Impact of Social Isolation:
The pandemic has also brought to light the potential exacerbation of PANS/PANDAS symptoms due to increased levels of inflammatory markers like IL-6 and CRP caused by social isolation, even in the absence of infection.
Treatments like Intravenous Immunoglobulin (IVIG) that target the autoimmune aspect have shown promise in managing PANS and critically ill COVID-19 patients, underscoring a potential intersection in the immune profiles of PANS/PANDAS and COVID-19 patients.
Unraveling the autoimmunity in PANS and PANDAS is pivotal for better diagnostic and therapeutic approaches. The COVID-19 pandemic has amplified the necessity of understanding these mechanisms, offering a pathway towards improved management and a better quality of life for the affected children and their families amid these challenging times.