AANEM Connect

I would greatly appreciate any comments or thoughts regarding the further management of a patient who has given me permission to present his case in this forum. 

He is a 66yo male who underwent a liver transplant for alcoholic cirrhosis complicated by hepatocellular carcinoma in February 2018. He noted difficulty walking immediate post transplant with progressive sensory loss and imbalance. In early 2021, this became signifiantly worse and culminated in a fall with an ankle fracture. During admission, I was consulted and he was noted to have a sensory > motor polyneuropathy with lower limb predominance and nerve conduction studies confirmed a generalised demyelinating polyneuropathy. This was in the context of being on tacrolimus and mycophenolate therapy. Initial consideration was given to the possibility of a tacrolimus associated neuropathy given the onset at the time of transplant with possible worsening in the setting of dose escalation.

He was subsequently found to have IgM kappa paraprotein (3g/L) and positive high titre MAG antibodies on both ELISA and Western blot.

He had significant but incomplete clinical response to IVIg therapy with improvement in balance and distal strength. He remains on mycophenolate and a reduced dose of tacrolimus. He is on maintenance IVIg and notices his foot "slapping" more when walking in the week prior to his 4 weekly infusions.

Is there cause to push to switch his tacrolimus to an alternative - such as cyclosporin which will put him at risk of developing diabetes? Would anyone consider rituximab therapy for MAG neuropathy given persisting gait dysfunction - taking into account he is already immunosuppressed for his liver transplant? What are your thoughts on the development of a presumably autoimmune neuropathy in the setting of immunosuppression?

Thank you for your wisdom!