Intravenous immunoglobulin and plasma exchange prescribing patterns for Guillain-Barre Syndrome in the United States-2001 to 2018.

Introduction/aims: Randomized controlled trials show that repeat intravenous immunoglobulin (IVIG) dosing and plasma exchange (PLEX) followed by IVIG (combination therapy) have no additional therapeutic benefit in Guillain-Barre Syndrome (GBS) non-responders. Furthermore, the delineation between GBS and Acute Onset CIDP (A-CIDP) can be particularly challenging and carries therapeutic implications. We aimed to evaluate the presence of repeat IVIG, combination therapy, and diagnostic reclassification from GBS to CIDP.

Methods: We performed a retrospective study of a large healthcare database for patients with GBS in the US from 2001 to 2018. We identified individuals initially diagnosed with GBS and later re-classified as CIDP. Multivariable logistic regression models were developed to determine associations between patient factors and repeat IVIG dosing, combination therapy, and diagnostic re-classification from GBS to CIDP.

Results: We identified 2325 patients with GBS. A total of 39.7% received repeat IVIG and 6.1% received combination therapy. The proportion of individuals initially diagnosed with GBS and then re-classified as CIDP was 32.0%. Repeat IVIG, combination therapy, and diagnostic reclassification remained stable over time. Female sex (OR 0.79, 95% CI 0.65-0.96) and medium-high net worth (OR 0.64, 95% CI 0.45-0.90) associated with repeat IVIG therapy, while Asian ethnicity associated with diagnostic re-classification from GBS to CIDP (OR 1.77, 95% CI 1.09-2.86).

Discussion: Repeat IVIG dosing was quite common in GBS before newer trials suggesting harm in non-responders, and IVIG/PLEX combination therapy continues to persist despite strong evidence against use in non-responders. Further, nearly one in three patients initially diagnosed with GBS is subsequently diagnosed with CIDP, but the reasons are unclear.