Response to “Comment on: A Case of Acute‐Onset <scp>CIDP</scp> With Pleocytosis in Cerebrospinal Fluid Presenting With Recurrent Acute Limb Weakness”

The Author Reply: We are grateful to Drs. Kumar and Chander [1] for their insightful comments and careful reading of our case report [2]. We appreciate the opportunity to respond and provide clarifications regarding the points raised. First, with respect to the infectious etiology and cerebrospinal fluid (CSF) pathogen testing, we agree that viral radiculitis and meningitis can present with CSF pleocytosis and elevated IL-6. In our case, we performed a comprehensive infectious workup including CSF FilmArray meningitis/encephalitis panel [3] and CSF culture, all of which yielded negative results. Given the repeated improvement with immunotherapy and the absence of infectious markers, we believe an autoimmune mechanism to be the most consistent explanation. Second, regarding therapeutic response and its attribution, we acknowledge the inherent difficulty in assigning clinical and biomarker improvements to a single therapeutic modality in a patient who received multiple treatments. The initial acute episodes were managed with corticosteroid pulse therapy and plasma exchange. Whereas the patient had experienced recurrent hyperacute exacerbations during periods of treatment mainly with corticosteroids, continued maintenance intravenous immunoglobulin (IVIg) administration is considered important to prevent relapse [4]. Thus, sustained clinical and CSF biomarker improvements (IL-6, protein, and cell count) were observed after the initiation and continuation of maintenance IVIg. While the potential contribution of prior therapies cannot be excluded, the temporal association of the improvement supports a beneficial role of maintenance IVIg to prevent relapse. Nonetheless, we agree that therapeutic attribution in such cases remains complex and requires cautious interpretation. The authors have nothing to report. The data that support the findings of this study are available from the corresponding author upon reasonable request.