The risk of neuropathy associated with biological therapy in juvenile idiopathic arthritis children.

OBJECTIVES

To evaluate the risk of neuropathy induced by biological drugs in children with juvenile idiopathic arthritis, clinically and by electrodiagnosis and ultrasonography.

PATIENTS AND

METHODS

Eighty juvenile idiopathic arthritis (JIA) patients were divided into 2 groups: 40 patients under treatment of biologic drugs and conventional disease-modifying antirheumatic drugs (DMARDs) in group I for at least 6 months, and 40 patients under treatment of conventional DMARDs only in group II. Assessment was done using pediatric-modified total neuropathy score (Ped-mTNS), electrodiagnostic (EDX) tests, and nerve ultrasound.

RESULTS

There was a significant increase in Ped-mTNS, distal latency of peroneal nerve, and latency of tibial F wave and H-reflex, and a significant decrease in conduction velocity of both peroneal and tibial nerves in group I in comparison with group II. A positive correlation was detected between Ped-mTNS, cross-sectional area, and distal motor latency of the peroneal nerve, and between Ped-mTNS and tibial F wave latency, and a negative correlation between motor conduction velocity of the peroneal nerve and Ped-mTNS in group I. Absent H-reflex in 2 cases in group I.

CONCLUSIONS

Demyelinating peripheral neuropathy can represent a rare adverse event in JIA children treated with biological agents. Key Points • The potential risks associated with biological therapy in JIA patients and the importance of neuropathy screening in these patients. • Nerve ultrasound exhibits lower sensitivity compared to nerve conduction studies for detecting early or subclinical demyelination, as morphological changes may not be apparent on imaging despite measurable functional neurophysiological impairment. • Nerve ultrasound has a complementary role in the diagnosis of peripheral neuropathy, but clinical examination and electrodiagnostic testing remain the actual gold standard for the evaluation of the peripheral nervous system.