Objective:

We describe a case emphasizing the necessity of considering patient phenotype when evaluating those with positive autoimmune serologic assay testing. This case outlines a patient with longitudinally extensive transverse myelitis following notable immune system altering therapies throughout the treatment of refractory diffuse large B-cell lymphoma (DLBCL).  

Background:

Transverse myelitis is a rare disorder of the spinal cord that can result in an array of symptoms including weakness, sensory changes, and autonomic symptoms. The differential for this condition is broad but includes many treatable conditions; with emerging options for immune modulating therapy, clinicians must consider adverse effects of stem cell transplant and chimeric antigen receptor T-cell (CAR-T) therapy.  

Design/Methods:

N/A 

Results:

A 40-year-old male presented with bilateral lower extremity paresthesias and allodynia following treatment of refractory DLBCL including multiple regimens of chemotherapy, CAR-T therapy, and allogenic stem cell transplantation. His course had been complicated by stage 4 GVHD requiring treatment with intravenous steroids, tacrolimus, budesonide, ruxolitinib, and photopheresis followed by weekly maintenance IVIg.  One year after transplantation, he was reimmunized. Shortly thereafter, maintenance IVIg was discontinued, and he began to develop paresthesias and allodynia that progressed to sensory loss and bilateral lower extremity weakness. Imaging with MRI revealed longitudinally extensive transverse myelitis from C2-T11. CSF evaluation showed lymphocytic pleocytosis with autoantibody panel negativity, but serum showed GABA-B autoantibodies. However, this serology was inconsistent with the patient’s phenotype, prompting alternative considerations. Neural autoantibody repeat evaluation was negative. After failing methylprednisolone, the patient resumed treatment with IVIg and experienced dramatic improvement both clinically and radiographically. The etiology of his transverse myelitis remains unknown but is interpreted as either atypical GVHD or vaccine-mediated hyperreactivity. 

Conclusions:

This case demonstrates the importance of considering patient phenotype when evaluating the etiology of autoimmune neurologic disease and the value of retesting.