Successful Detection of Renal Involvement in Sjögren's Syndrome Secondary to Systemic Lupus Erythematosus by Renal Biopsy

Abstract

An 80-year-old man presented with a mildly decreased renal function and increased anti-double-stranded-DNA (anti-dsDNA) antibody levels, and met the diagnostic criteria of the American College of Rheumatology for systemic lupus erythematosus (SLE). However, the incremental increase in creatinine levels and the mild proteinuria were inconsistent with lupus nephritis. We performed a renal biopsy, which revealed interstitial nephritis and minor glomerular abnormalities. Further examinations determined that the renal lesion was due to Sjögren's syndrome secondary to SLE. Following treatment with oral prednisolone, the patient's renal function improved as his anti-dsDNA antibody levels decreased. This case report indicates that renal biopsy should be considered even in elderly individuals when it may assist in the diagnosis, treatment, and prognosis of the patient.

Tubulointerstitial lesions converted into lupus nephritis

“…Tubulointerstitial involvement has been observed in approximately two‐thirds of lupus nephritis patients, and this is often accompanied by severe glomerular lesions, although it is not included in the classification system. However, it has been reported that there were only 13 cases of predominant tubulointerstitial lupus nephritis in literatures written in the English language, indicating that predominant tubulointerstitial nephritis is rare . The present case did not provide any evidence of glomerular lesion from the onset urine analysis, suggesting a tubulointerstitial lesion.…”

“…However, it has been reported that there were only 13 cases of predominant tubulointerstitial lupus nephritis in literatures written in the English language, indicating that predominant tubulointerstitial nephritis is rare. 1,8 The present case did not provide any evidence of glomerular lesion from the onset urine analysis, suggesting a tubulointerstitial lesion. The percutaneous renal biopsy results revealed interstitial fibrosis and heavy atrophy of the renal tubules with minimal glomerular impairment.…”

“…The reason may be that the tubulointerstitial lesion in the present case was caused by Sjögren's syndrome diagnosed at six months early before SLE was established, although this is rare in patients with SLE and Sjögren's syndrome. 1 In the present case, another main characteristic is that the onset renal pathological lesion was converted into different pathological changes after seven years. It is well-known that glomerular lesions in patients with lupus nephritis may be converted from one class to another.…”

“…However, the immunofluorescence results in the present case showed the negative staining of immunoglobulins and complements in the renal tissue. The reason may be that the tubulointerstitial lesion in the present case was caused by Sjögren's syndrome diagnosed at six months early before SLE was established, although this is rare in patients with SLE and Sjögren's syndrome …”

“…The presence of glomerular injuries is the main pathogenetic factor of renal impairment in systemic lupus erythematosus (SLE), while predominant tubulointerstitial lesions are rare in SLE. 1,2 Although some cases of predominant tubulointerstitial lesion have been reported in patients with SLE, 3 there were few cases with follow-up outcome of long-term treatment, especially for patients with repeat renal biopsy results. 4 We present a case of SLE with Sjögren's syndrome and onset predominant tubulointerstitial lesions, who was followed up for more than eight years.…”