High rates of abnormal lab results shared between PANS and pediatric OCD

Researchers have identified high rates of abnormal laboratory findings in pediatric patients with pediatric acute-onset neuropsychiatric syndrome (PANS) and idiopathic obsessive-compulsive disorder (OCD) and/or tic disorders, with no significant differences between conditions, publishing their findings in JAMA Network Open.¹

PANS is defined by the sudden onset of OCD, restrictive food intake, and/or tics, alongside at least 2 psychiatric symptoms.² Clinical PANS management has been shaped around a potential immunologic etiology, despite a lack of solid evidence.¹ Additionally, some PANS treatments are not considered when treating idiopathic OCD, eating disorders, and/or tics.

“Moreover, somatic and autoimmune conditions have also been reported in individuals with idiopathic OCD and tic disorders, underscoring the need for comparison,” wrote investigators.

Comparing laboratory investigations

The case-control study was conducted to assess whether recommended laboratory investigations of PANS differ from those with OCD and/or tic disorders, and whether these evaluations help identify underlying somatic conditions. Participants included children aged 4 to 18 years referred to 2 specialized clinics in Stockholm, Sweden.

These patients were referred between January 1, 2020, and September 19, 2023, and needed to have clinically significant OCD, restricted food intake, and/or tic symptoms, completed laboratory assessment within 2 months, and met PANS criteria to be included in the analysis. Controls included those meeting diagnostic criteria for OCD, tic disorder, or both.

European clinical guidelines were used to evaluate suspected cases of PANS or pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections. These included comprehensive medical and psychiatric assessments, as well as a review of medical records.

Patients with neurologic symptoms received consultation from child neurologists, undergoing additional complementary cerebrospinal fluid analysis, brain MRI, and electroencephalography. Investigators also conducted complementary investigations within 6 months of the first visit for immune activation, neuroinflammation, and other somatic conditions.

Key findings and laboratory results

There were 109 participants included in the final analysis, 51 of whom were in the PANS group. The mean age of these patients was aged 10.2 years, and 66.7% were boys and 33.3% were girls. Of the 58 controls, 53 had OCD, 21 a tic disorder, and 16 OCD and a tic disorder. Symptom onset was reported at a mean aged 8.1 years in the PAN group vs aged 10.6 years for controls.

In the PANS group, 86.3% of patients had abnormal laboratory findings vs 96.6% of the control group. These patients most often presented with at least 3 abnormal findings and at least 4 abnormal findings, respectively.

A median 27 variables were analyzed in the PANS group vs a median 28 variables in the control group. At least 1 abnormal finding was reported in 82.4% and 93.1% of these groups, respectively.

Low ferritin levels, low leukocyte levels, and low complement component levels were the most common abnormal findings in the PANS group, with rates of 28.6%, 25%, and 21.4%, respectively. In comparison, the most common findings in the control group were low leukocyte levels at 41.4%, low orosomucoid levels at 25.5%, and low vitamin D levels at 25.5%.

Complementary investigations and conclusions

Of patients tested for group A streptococcal infections, 16.7% in the PANS group tested positive vs 8.5% in the control group. No laboratory variables significantly differed between groups.

Complementary investigations were provided to 35.3% of patients in the PANS group. However, none of these patients had oligoclonal bands, 7.1% tested had pleocytosis, and 22.2% tested had slightly elevated albumin levels. Underlying somatic conditions were not common in these patients.

“Given the potentially invasive nature and cost of these investigations, we urge clinicians to make judicious decisions regarding the implementation of the current recommendations,” wrote investigators.

References

1. Vasiljevic S, Winerdal ME, Wickström R, et al. Recommended medical investigations in pediatric acute-onset neuropsychiatric syndrome. JAMA Netw Open. 2026;9(3):e262618. doi:10.1001/jamanetworkopen.2026.2618
2. Swedo S, Leckman J, Rose N. From research subgroup to clinical syndrome: modifying the PANDAS criteria to describe PANS (pediatric acute-onset neuropsychiatric syndrome). Pediatr Ther. 2012;2(2):8. doi:10.4172/2161-0665.1000113