We thank Eric Buenz and colleagues for their comments on the treatment of Guillain-Barré syndrome. On the basis of evidence that intravenous immunoglobulins (IVIg) and plasma exchange (PLEX) are equally efficacious in treating Guillain-Barré syndrome, we suggested that—because of the high costs of IVIg—PLEX should be considered as first-line therapy especially in resource-constrained environments. We agree that rising health-care costs are also relevant in resource-rich countries like Canada and Australia. In this respect, there are several relevant issues in the decision to treat Guillain-Barré syndrome with PLEX or IVIg. First, the actual costs for IVIg vary substantially between countries and even between hospitals depending on local policy and price negotiations. Second, the availability and experience of using PLEX varies greatly between centres. The rapid availability, greater convenience, and the good side-effect profile—including the lower number of multiple complications and the fact that IVIg in Guillain-Barré syndrome is more likely to be completed than PLEX—is likely to favour the use of IVIg for treatment of this condition from a medical point of view. The budget spend on IVIg could be increasing over time and we agree that Guillain-Barré syndrome is a disease in which in-hospital related costs can be calculated quite accurately. A much larger budget is probably spent on IVIg in patients with chronic neuromuscular diseases requiring long-term treatment compared with treatment of Guillain-Barré syndrome, which only requires one or a few courses of IVIg. Chronic disorders like chronic inflammatory demyelinating polyneuropathy (CIDP) often require repeated IVIg infusions once every 2–4 weeks over a period of many years. As patients with CIDP frequently require long-term treatment, this disorder is also a good candidate for health economic studies. A study on comparative effectiveness research in CIDP is planned in the Netherlands. Importantly, one of the reasons for increased use of IVIg could be the treatment of patients with a mimic of CIDP. The diagnosis of CIDP is difficult and requires dedicated experience. Additionally, a substantial proportion of patients with CIDP are still receiving treatment despite having an inactive disease or being in remission. We agree with Buenz and colleagues that proper health economic studies are needed both in acute and in chronic neurological diseases.

We also thank David Durrheim for his timely and important remarks on highlighting other causes of acute flaccid paralysis (AFP), notably poliomyelitis which has recently reappeared in Nigeria. Although we tend to dichotomise AFP into infectious and post-infectious (ie, Guillain-Barré syndrome) or non-infectious causes, the two go hand in hand. Moreover, we should not limit ourselves to only considering polio virus. Japanese encephalitis virus, for example, can directly infect motor neurons to produce a polio-like syndrome, as well as being able to trigger Guillain-Barré syndrome. Recent experience with Zika virus-associated AFP and Guillain-Barré syndrome raises similar issues in which the distinction between direct infection and post-infectious autoimmunity might not be so clearly delineated, clinically or pathophysiologically, and much work needs to be done to resolve this.6 We would welcome global efforts to join forces in considering all causes of AFP under a single surveiliance programme and to capture all causes under this umbrella.

doi.org/10.1016/S0140-6736(17)30055-7, hdl.handle.net/1765/95606
The Lancet
Department of Neurology

Willison, H., Jacobs, B., & van Doorn, P. (2017). Guillain-Barré syndrome: surveillance and cost of treatment strategies – Authors' reply. The Lancet, 389(10066), 253–254. doi:10.1016/S0140-6736(17)30055-7