Dramatic rebounds of MS during pregnancy following fingolimod withdrawal

In MS, discontinuation of some therapies may result in a transitory, possibly overwhelming, increase in disease activity. We report 2 cases of severe clinical rebound after fingolimod suspension occurring in 2 patients following pregnancy. Clinical rebound was defined as the occurrence of new severe neurologic symptoms together with a significant increase of new or enlarging T2-weighted or gadolinium-enhancing T1-weighted lesions exceeding baseline activity, on treatment discontinuation. The first patient was diagnosed with MS in 2005. In the subsequent 3 years, she experienced several relapses and progressive increase of MRI lesion load despite the sequential introduction of weekly interferon-b1a, thrice weekly interferon-b1a and then glatiramer acetate. Natalizumab (NTZ) was then started (EDSS 3.0, JCV antibodies negative status), resulting in no evidence of disease activity for the following 40 months. On seroconversion, NTZ was interrupted in August 2011 beacause of the potential risk of progressive multifocal leukoencephalopathy (PML) and fingolimod was started. In March 2013, fingolimod was suspended as disease was stable (figure, A) and due to desire of pregnancy and potential risks of fetal exposure to fingolimod. Lymphocyte count was 0.34 3 10/L. In April 2013, she resulted pregnant. In July (eleventh week of pregnancy), she abruptly developed quadriplegia and signs of severe cognitive impairment (EDSS: 9.0). Lymphocyte count was 1.54 3 10/L. One gram of methylprednisolone was administered IV for 5 days with partial recovery (EDSS 7.0). One month later, she developed locked-in syndrome (EDSS 9.5). Brain MRI showed a dramatic increase of white-matter abnormalities with many gadolinium-enhancing lesions (figure, B). PML was excluded by CSF analysis. IV methylprednisolone followed by IV immunoglobulins were administered with no success. Plasma exchange was not considered because of the possible adverse effects on maternal hemodynamics and limited experience on pregnant patients with MS. On therapeutic abortion, she received IV cyclophosphamide (2 g/m), improving clinically (EDSS 7.0) and radiologically (figure, C). One month later, her clinical condition deteriorated (EDSS 8.0) with worsening of brain MRI (figure, D). She was treated again with IV cyclophosphamide (1 g/m), but a few days later, she developed septic shock and died. The second patient was diagnosed with MS in 1995 and was treated from 1999, first with interferon-b1a once weekly, then interferon-b1a 22 mcg 3 times weekly and subsequently interferon-b1a 44 mcg 3 times weekly. In 2004, because of insufficient disease control, she received 4 infusions with mitoxantrone 12 mg/m monthly followed by interferonb1b. In May 2005, interferon-b1b was suspended when the patient resulted pregnant. In 2006, following childbirth, she started azathioprine and after a few months, because of disease progression, she was infused with 4 additional doses of mitoxantrone. In 2007, she started NTZ with no signs of disease activity for 28 months. In October 2010, NTZ was suspended fearing PML. In June 2011, she started fingolimod with incomplete disease control. In September 2014 (EDSS 3.0), she was again pregnant and therapy was suspended. Lymphocyte count was 0.73 10/L. Four weeks later, with a lymphocyte count of 2 3 10/L, she experienced severe left leg monoparesis and dysarthria (EDSS 6.0). IV methylprednisolone was administered with no results. Four weeks later, therapeutic abortion was performed. One week later, she presented with tetraplegia and anarthria (EDSS 9.5). She received high-dose steroids, followed by plasma-exchange and rituximab (two 1-g infusions 15 days apart) with radiologic and clinical improvement (EDSS 5.5 on April 2015). In May 2015, dimethyl fumarate was started with slow progression to EDSS 6.5 (January 2017). Suspension of therapies affecting lymphocytes trafficking to the CNS, such as NTZ and fingolimod, may rarely result in disease rebound. Compared with dramatic deterioration of disease following NTZ suspension, fingolimod withdrawal usually results in mild disease recrudescence, mostly controlled by steroids. In the reported cases, rebound after fingolimod suspension was rapidly devastating despite occurring during the early phase of pregnancy, a condition associated with a significant reduction of