Hypokalemic Paralysis as a Presenting Manifestation of Primary Sjögren's Syndrome Accompanied by Vitamin D Deficiency

Abstract PrimarySjogren’ssyndrome(pSS)isachronicautoimmunediseasecharacterizedbyprogressivelympho-cyteinfiltrationoftheexocrineglands.Overtorlatentrenaltubularacidosis(RTA)isacommonextraglandu-larmanifestationofpSS.VitaminDdeficiencyisassociatedwithautoimmunedisorders;however,thepoten-tialcorrelationbetweenpSSandvitaminDdeficiencyisrarelydiscussed.ThecurrentpatientpresentedwithdistalRTA,hypocalcemia,andhypophosphatemiathatwerefoundtobesecondarytobothvitaminDdefi-ciencyandpSS.InpatientsdiagnosedwithbothdistalRTAandvitaminDdeficiency,cliniciansshouldcon-siderautoimmunediseasessuchaspSS,asapossibleunderlyingetiology. Key words: Sjogren’ssyndrome,vitaminDdeficiency,renaltubularacidosis,hypokalemicparalysis,autoimmunediseases (Intern Med 52: ★★★ - ★★★ , 2013)(DOI: 10.2169/internalmedicine.52.0899) Introduction PrimarySjogren’ssyndrome(pSS)isadiseaseoftheexocrineglandsthatpresentswithdryeyesandmouth.Ex-traexocrineorgansystemsmayalsobeinvolved,includingtheskin,lungs,gastrointestinaltract,nervoussystem,mus-cularskeletalapparatus,andkidneys(1).ThereportedrateofrenalinvolvementinpatientswithpSSisvariable,rang-ingfrom2-67%(2).Thespectrumofrenaldiseaseincludesinterstitialnephritis,renaltubularacidosis(RTA),tubularproteinuria, nephrogenic diabetes insipidus, glomeru-lonephritis,andrenalfailure(3).Themostcommonmani-festationsarerelatedtotubulardysfunctionresultingfromchronicinterstitialnephritiswithprominentCD