Background and Importance Treatment with adalimumab offers an improvement in autoinmune diseases and it is considered well tolerated. Demyelination with adalimumab have been described in several case reports.

Aim and Objectives To describe two cases of Multiple sclerosis (MS) triggered by adalimumab treatment.

Material and Methods Descriptive and retrospective clinical cases that occurred in October 2021. Data were obtained by medical records. The causal relationship between adalimumab and MS was assessed using the Naranjo’s algorithm.

Results Patient 1, 41-year-old, woman with psoriasis diagnosed 5 years ago in treatment with adalimumab for 2 years with no history of neurological disease.

She presented loss of strength, ataxia and paresthesias. She was treated with methylprednisolone for 5 days with functional improvement and adalimumab was stopped.

Magnetic resonance imaging (MRI) revealed intramedullary lesion of C2, showing two possible diagnosis: inflammatory myelitis as the first possibility or tumour origin. She presented systemic autoimmunity stigmas (positive antibodies antinuclear, oligoclonal bands (OCBs) positive in cerebrospinal fluid and serum and psoriasis).

Six months later, she had a new possible cervical outbreak. MRI showed the appearance of a parasagittal occipital cortico-subcortical lesion confirming the diagnosis of MS according to McDonald’s criteria (2017). She started treatment with dimethylfumate.

Patient 2, 43-year-old, woman with ankylosing spondylitis HLA-B27+ in treatment with adalimumab 5 months ago and no history of demyelinating diseases.

She presented ataxia and hemihypoesthesia She was treated with methylprednisolone for 5 days with functional improvement stopping adalimumab treatment.

In the MRI, multiple lesions with dissemination criteria in space (1 periventricular, 1 infratentorial), and in time (only one of them with gadolinium uptake, currently apparently asymptomatic), the patient met McDonald’s criteria (2017) for MS with OCBs negative and she started treatment with ocrelizumab.

Naranjo’s algorithm determined as adverse drug reactions probable in patient 1 and possible in patient 2.

Conclusion and Relevance A potential link between adalimumab and MS was related in these cases. Although this relationship have been associated in rare cases, adalimumab should be avoided in patients with history of demyelinating disorders. Patients should be informed of possible symptoms at the start of therapy and treatment should be discontinued if they develop them.

References and/or Acknowledgements 1. doi:10.1007/s00296-012-2625-8

2. http://dx.doi.org/10.1155/2016/1423131

Conflict of Interest No conflict of interest