[Hypokalemic paralysis: the first presentation of primary Sjögren's syndrome]

The Sjögren's syndrome is a systemic autoimmune disorder characterized by chronic inflammation of the exocrine glands with extraglandular manifestations in up to 25% patients. Renal involvement occurs in 18.4-67% of cases, with tubulointerstitial nephritis being the most frequent pathology. We present the case of a 37 year-old woman admitted because of generalized grade 2 muscle weakness which developed over a week. We detected: hypokalemia, rhabdomyolysis, urinary pH 6.5, proteinuria and metabolic acidemia. The laboratory tests suggestive of distal renal tubular acidosis with hypokalaemia led to the diagnosis of lymphoplasmocytic tubulointerstitial nephritis, which was confirmed by renal biopsy, and to a clinical suspicion of Sjögren's syndrome. Primary Sjögren's syndrome was diagnosed in this patient based on the following criteria: xerophthalmia, xerostomia, sialadenitis, positive anti-SSA and anti-SSB antibodies, and absence of criteria for lupus and rheumatoid arthritis. During hospitalization, the patient developed deep vein thrombosis. Tests showed positive antiphospholipid antibodies and the diagnosis of secondary antiphospholipid syndrome was made. She was treated with potassium, bicarbonate, steroids, ramipril and warfarin. The authors wish to highlight the extraglandular manifestations and in particular the rarity of hypokalemic paralysis as the presenting manifestation of primary Sjögren's syndrome.