Abstract: PUB315
Myasthenic Crisis (MC) Precipitated by Omalizumab (Om) Therapy (Rx): A Rare Adverse Reaction
Session Information
Category: Pharmacology (PharmacoKinetics, -Dynamics, -Genomics)
- 1800 Pharmacology (PharmacoKinetics, -Dynamics, -Genomics)
Authors
- Attique, Hassan Bin, Uconn Health, Farmington, Connecticut, United States
- Trivedi, Ruchir D., Uconn Health, Farmington, Connecticut, United States
Background
Om is humanized glycosylated monoclonal(M) antibody(Ab) of IgG subtype that specifically binds to circulating immunoglobulin E (IgE) and hence has a role in treatment of severe allergic asthma.Om or its constitutive ingredients can trigger immune cross-reactivity and generate secondary autoimmune(AI) reaction by promoting formation of acetylcholine receptor (AChR) or muscle specific tyrosine kinase (MuSK) antibodies(Abs) and potentially precipitate MC.Majority of described adverse reaction to Om is limited to ocular myasthenia gravis (MG).We describe a case of full blown MC from Om with complete resolution of symptoms after therapeutic plasmapharesis (TPE) and stopping Om Rx.
Methods
61 year old female who had initial diagnosis of MG for almost 20 years,was on maintenance Hemodialysis secondary to hypertensive nephrosclerosis for almost a decade.Around 7 years ago,she was started on Om Rx for non-atopic asthma and she was receiving it on twice monthly basis since then.Two years ago,she started having exacerbation of MG requiring intravenous immunoglobulin (IVIG) Rx.She counted 5 separate relapses at 3 months interval during this time requiring multiple courses of IVIG Rx.Initially symptoms were limited to ocular MG. However,last three relapses were involving difficulty in breathing and swallowing.She improved with three sessions of 1 x volume TPE and stopping Om Rx.
Results
Om has a biological half life of 5 days and typically given twice a month.Information derived from WHO Global individual case safety record database,VigiBase® suggests that there can be latency period of 0.5 to 2.5 years between starting of Om Rx and first appearance of MC symptoms.Precise etiopathogenesis of MG in setting of Om is not well described.Proposed mechanisms may include immune cross-reactivity, impurities in drug triggering secondary AI response and leakage of immunogenic protein A.Precipitation of MC has also been described with other M Abs like Nivolumab and Ipilimumab.
Conclusion
In conclusion, our case report suggests that high level of vigilance is required while using newer M Abs as reversible side effects such as MC can occur with use of Om years after its first exposure through complex and yet unidentified AI mechanisms.Om due to its high molecular weight, less protein binding and volume of distribution, can be effectively removed by TPE and this may provide a therapeutic option.