Cladribine in a desoxiadenosine analogue approved for Multiple Sclerosis (MS) treatment. It produces rapid B and T cells depletion, associating lymphopenia in some cases the first months after treatment. Neutropenia is extremely rare.
We present one patient with MS that develops severe neutropenia after the second dose of the first cycle of cladribine.
We reviewed patient's clinical history, complementary tests and outcome, as well as available bibliography about this topic.
53 year-old female with past medical history of psoriasis. She suffered from an optic neuritis in 2008. Brain MRI done then showed typical MS lesions. Because of clinical and radiological stability, she did not receive any disease modifying therapy until 2018. Then, she was started on dimethyl fumarate that was discontinued a few months later due to lymphopenia and joints pain. Once the lymphocyte count was normal, she was started on cladribine in December 2019. One week after the second dose of the first cycle, she presented with asthenia. Gabapentine had also been added due to neuropathic pain. Blood test revealed severe leucopenia (0.51 x 109/l), grade IV lymphopenia (0.19 x 109/l) and grade IV neutropenia (0.20 x 109/l). Rest of the bool count and smear were normal. Bone marrow aspirate showed slight hypocellularity with good representation of the three series, suggestive of post-chemotherapy aplasia recovery, indicative of cladribine induced neutropenia. Granulocyte colony stimulating factor was administered during 2 days, with progressive recovery until normal neutrophil count was achieved within 10 days. Grade II lymphopenia persists (0.74 x 109/l) after 3 months. The patient has remained afebrile and without any incidence. Evaluation of the second cycle of cladribine according to clinical, radiological and blood test evolution is still pending.
Neutropenia is a very rare adverse effect of cladribine in MS treatment, but it may be life-threatening. Thus, clinical and blood test monitoring is essential. In the case presented, we postulated that gabapentine may have an additive effect in cladribine hematologic toxicity.