Life-Threatening Severe Hypokalemia Leading to a Diagnosis of Sjogren's Syndrome in a Young Female

Document Type

Conference Proceeding

Publication Date

10-2023

Publication Title

Chest

Abstract

INTRODUCTION: Sjögren's syndrome(SS) is a chronic autoimmune inflammatory disorder classically affecting the salivary and lacrimal glands causing dryness of the eyes and mouth. Sjögren's syndrome most commonly affects women in their 6th-7th decade of life but can affect younger adults. We present the case of a young patient who was diagnosed with Sjögren's syndrome after presenting with severe hypokalemia secondary to type I renal tubular acidosis (RTA). CASE PRESENTATION: A 32-year-old woman with a past medical history of cutaneous leukocytoclastic vasculitis presented with a 1-week history of increasing lower extremity weakness, muscle cramps, and fatigue, after a fall. On admission: K: 1.6 mEq/ L, Mg: 1.7mEq/L, Bicarbonate: 7 mmol/L, Anion gap: 13, pH: 7.24, Phos: 1.6 mg/dL, Urinary K: 15.8 mmol/L, trans-tubular K gap: 12, Urine anion gap: 6.8, Urine pH: 7, UPCR: 1.43. An EKG was significant for a QTc of 703 ms, and CT of the head was negative for intracranial bleeding but noted multiple small calcifications in both parotid glands. Renal ultrasound noted bilateral small non-obstructing renal calculi. The patient's lab values were indicative of a potassium wasting non-anion gap metabolic acidosis, most likely due to a Type I RTA. Autoimmune workup returned positive for ANA > 1:1280, anti-SSA: 358 U/mL, and anti-SSB: 528 U/mL. A renal biopsy was indicative of acute and chronic lymphocytic tubulointerstitial nephritis commonly seen in Sjögren's syndrome. She received total 360-380 mEq of potassium and potassium level normalized within 48 hours. The patient was discharged with a regimen of prednisone 30 mg, Azathioprine 50 mg daily, as well as potassium replacement. She was symptomfree with marked lab improvement and normal EKG at the follow-up in 2 weeks. DISCUSSION: Severe hypokalemia (K+ <2.5 mEq/L) can cause significant life-threatening arrhythmias. Patients who present with SS-RTA tend to be younger, have a median age of 37 years, and have minimal sicca symptoms, as described in our case. In more than half of the cases (63.6%), the presenting clinical picture tended to be hypokalemic paralysis or even respiratory paralysis due to severe electrolyte derangements. Type II and IV renal tubular acidosis has also been described in SS but is significantly less common than type I. Tubulointerstitial nephritis is the predominant finding on renal biopsies of patients with SS, and more than 90% of patients have anti-SSA antibody positivity. Although salivary gland biopsy has a high positive yield, it is evaluated less frequently in patients with this presentation, possibly because of the lack of sicca symptoms. In our case, a biopsy was not necessary, as salivary gland involvement was incidentally proven on head CT, and the patient did not report any sicca symptoms. CONCLUSIONS: It is important to consider SS in young patients presenting with severe hypokalemia and normal anion gap metabolic acidosis due to the potential severity of the disease, patient demographics, and the need for timely intervention in the presence of effective treatment options

Volume

164

Issue

4 Suppl

First Page

A2091

Comments

Chest Annual Meeting 2023, October 8-11, 2023, Honolulu, HI

DOI

10.1016/j.chest.2023.07.1425

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