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Renal involvement in voltage‐gated potassium channel complex antibody–associated diseases
Author(s) -
Mulmuley Madhura,
Ambwani Varsha,
Jha Sanjeev,
Pradhan Sunil,
Katiyar Shweta,
Chaudhary Nandita
Publication year - 2020
Publication title -
clinical and experimental neuroimmunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.297
H-Index - 15
ISSN - 1759-1961
DOI - 10.1111/cen3.12605
Subject(s) - medicine , proteinuria , serology , antibody , immunology , kidney
Background Voltage‐gated potassium channel (VGKC) complex antibody–associated diseases are characterized by peripheral nerve hyperexcitability, autonomic disturbance, and encephalopathy. We report three patients of this disease with some unusual as well as novel findings. Case presentation Case 1 was a 36‐year‐old male who presented with painful cramps in legs and proximal weakness along with involuntary twitching in calves for a duration of 2 months. He also had associated insomnia, irritability, and hyperhidrosis. Electromyographic (EMG) study revealed features characteristic of VGKC antibody–associated diseases. His serology was positive for the components of VGKC, LGI1, and CASPR2. Case 2 was a 23‐year‐old male and Case 3 was a 26‐year‐old female who also had similar clinical presentations, EMG findings, and serologic status. Both male patients had a history of hydrocele with surgical aspiration and sclerosant injection, nearly 2 months prior to symptom onset. Routine evaluation of all the three patients revealed gross proteinuria. Histology performed in two patients revealed membranous glomerulonephropathy (MGN). Apart from symptomatic pharmacotherapy, all patients were initially given intravenous methylprednisolone to which only Case 3 responded while Cases 1 and 2 required one and two courses of intravenous immunoglobulins, respectively. Drug response included considerable resolution of proteinuria. Conclusions Immune mechanisms in VGKC antibody associated disease may sometimes cause renal involvement (MGN) with nephrotic‐range proteinuria. As all our patients with renal involvement had antibodies against both components of VGKC; this association needs further exploration.