Acquired hypophosphatemia osteomalacia associated with Fanconi’s syndrome in Sjögren’s syndrome

Abstract

Sjögren's syndrome is an autoimmune disorder involving exocrine glands that occurs alone or in association with various autoimmune and connective tissue diseases. The severity of Sjögren's syndrome ranges from isolated sicca syndrome to severe complications such as vasculitis, lung and renal involvement. Overt or latent renal tubular acidosis caused by autoimmune tubulointerstitial nephritis, is a common extraglandular manifestation in Sjögren's syndrome. Osteomalacia is a rare complication of renal tubular acidosis, and it was reported to be associated with distal renal tubular acidosis in Sjögren's syndrome. We report a 60-year-old woman who presented with multiple bone deformity and general muscle weakness. Osteomalacia was secondary to Fanconi's syndrome, and the Fanconi's syndrome was a result of renal involvement in Sjögren's syndrome. Fanconi's syndrome is a rare kidney manifestation in Sjögren's syndrome. It may be latent and may precede the subjective sicca symptoms. These findings suggest that evidence for Sjögren's syndrome should be sought in adult patients with unexplained osteomalacia and renal tubular acidosis, even in the absence of subjective sicca syndrome. Conversely, in patients with Sjögren's syndrome, early investigation and treatment of renal tubular dysfunction may prevent future complications, such as osteomalacia.

Osteomalacia as inaugural manifestation of Sjögren syndrome

“…Acidosis, hypophosphataemia, vitamin D deficiency are responsible of a release of calcium from the bone which can progress slowly to osteomalacia and osteoporosis 7. Deformities and fractures have also been described in the patient with tubular acidosis secondary to SS 8. As in our case, osteomalacia is exceptionally the first manifestation of SS 9.…”

Renal Tubular Acidosis in Sjögren's Syndrome: A Case Series

“…The sixth study [5] was a retrospective one and the rest were of patients with one-time investigations for renal manifestations. Though it was believed that the RTA presents mostly as a biochemical defect rather than with any symptom, there were case reports of muscle weakness [22], life-threatening paralysis due to hypokalemia [23], nephrocalcinosis [24,25] and metabolic bone disease [26,27,28,29,30,31,32]. …”

Primary Sjogren’s Syndrome and Distal Renal Tubular Acidosis: Presenting With Nephrogenic Diabetes Insipidus Secondary to Severe Hypokalemia-a Case Report.

“…Mucosal biopsy from lower lip for lymphocytic infiltration of the minor salivary glands showed chronic sialadenitis with evidence of epimyoepithelial islands and fibrosis strongly suggestive of Sjogren's disease. Dry eye was confirmed by Schirmer's test which was strongly positive (1mm at 5mins).As the literature suggests the association of dRTA (also Primary Sjogren's) with MBD [8][9][10][11][12][13][14], skeletal survey was also performed which showed moderate anterior wedging of the vertebral bodies(Lund 's criteria) and USG picture of bilateral renal microliths. DEXA Scan was not performed as this facility was not available at that time.…”