12392 Decoding LADA: A Closer Look At A Suspected Case Influenced By Prior IVIG Therapy

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Abstract Disclosure: A. Gondhi: None. S. Antharam: None. S.S. Bantu: None. B. Abdulhadi: None. Introduction: LADA(Latent Autoimmune Diabetes of Adults) is defined as a new diagnosis of diabetes after the age of 35, presenting with features of T2DM but with the presence of T1DM associated autoantibodies. Correct diagnosis of LADA is important since prognosis and therapy differs from T2DM. We report an interesting case of transient elevation of Glutamic Acid decarboxylase (GAD-65) antibodies due to IVIG therapy leading to a misdiagnosis of LADA. Case presentation:A 46-year-old women with hypothyroidism was referred for management of LADA. A few months prior to the referral, she was hospitalized for acute bacterial meningitis and developed flaccid quadriparesis concerning for Guillain Barre syndrome (GBS). She received multiple IVIG infusions, steroids with resultant hyperglycemia requiring insulin and was transferred to a rehabilitation facility. During her stay in rehab, her initial dose of glargine 20 units twice daily was titrated down rapidly once steroids are tapered. Blood work revealed HbA1C 6.1%, blood glucose 116 mg/dL, C-peptide levels 4.1 ng/ml (0.9 -7 ng/ml), and GAD-65 antibodies >250 (N<5 IU/ml). She was diagnosed with LADA and discharged on 2 units of glargine. Her primary care physician advised to stay on the 2 units of glargine since her GAD-65 antibodies were significantly elevated and then referred to the endocrine clinic. Repeat bloodwork in our clinic revealed HbA1c of 5.8%, GAD-65 antibodies were repeated twice and were found to be undetectable <5. She was taken off insulin and has been doing well since. Discussion:IVIG is derived from plasma pooled from donors, used to treat a variety of diseases. Autoantibodies contained in IVIG may result in false positive serum tests if levels are checked soon after the infusion. This phenomenon has been documented in previous cases involving treponemal, H. pylori, hepatitis C as well as ANA antibodies. Increases in anti-GAD levels post-IVIG therapy have been previously reported. We saw a similar scenario in our patient, who was initially diagnosed with LADA and started on insulin due to an observed elevation in GAD 65 levels. However, this elevation was transient with negative repeat levels a few months later. Conclusion: Our case highlights the importance of recognizing that IVIG infusions can lead to the transfer of and to transient elevations in autoantibodies including GAD-65, which may lead to misdiagnosis and unnecessary therapies.