How Sjögren’s syndrome may influence the expression of other connective tissue diseases
The influence of secondary Sjögren’s on the course of other connective tissue diseases has not been closely examined. In rheumatoid arthritis patients the coexistence of secondary Sjögren’s reportedly has little effect on the course of arthritis or other clinical manifestations. however, dryness of the gastrointestinal tract from sjögren’s syndrome could potentially exacerbate a variety of problems common to these disorders including reflux, dysphagia, dyspepsia (upset stomach) and constipation. Respiratory dryness from Sjögren’s could not only aggravate chronic cough due to interstitial lung disease but also predispose to recurrent respiratory infections. In lupus, two studies suggest that secondary Sjögren’s is associated with an increasedincidencee of erosive polyarthritis, an uncommon complication of SLE (Systemic Lupus). In scleroderma, a study of over 800 people reported that patients systemic sclerosis and secondary Sjögren’s (particularly the CREST variant) were at increased risk of developing vasculitis.
Another study reported that autoimmune liver disease, particularly primary biliary cirrhosis, was more prevalent in scleroderma patients with secondary Sjögren’s compared to scleroderma patients alone. Further studies will shed additional light on these observations.
Evolution of Sjögren’s syndrome into other disorders
As alluded to previously, patients various connective tissue disorders including Sjögren’s syndrome share overlapping clinical and laboratory features and are sometimes difficult to tell apart. Rheumatoid arthritis, for example, may be complicated by secondary Sjögren’s, and the initial manifestations of primary Sjögren’s can include a rheumatoid like polyarthritis with rheumatoid factor in the blood. Sjögren’s syndrome was once thought to be a benign variant of lupus, and the presence of anti-SSA and SSB antibodies in both diseases suggests a common pathogenetic mechanism. Reports exist in the medical literature of patients who met criteria for both diseases at the time of presentation and were therefore felt to have an SLE-Sjögren’s overlap syndrome. Not surprisingly, there are even reports of individuals who started with one disease and evolved into another.
One study from France described 55 patients who presented with sicca symptoms, anti-SSA or SSB, other manifestations of connective tissue disease, and fulfilled the European diagnostic criteria for primary Sjögren’s.
Other autoantibodies tested negative. During a subsequent period of 12-14 years, four patients developed new signs and symptoms (malar rash, pleuropericarditis, glomerulonephritis) thought to be atypical for Sjögren’s. Follow-up testing revealed the presence of anti-Srn (two patients) and anti-double stranded DNA (two patients) antibodies, and these patients were eventually diagnosed with lupus according to the American college of Rheumatology Criteria. In another report a patient with primary Sjögren’s syndrome (dry eyes, dry mouth, anti-SSA/SSB) turned anticentromere positive about three years after he developed parotid swelling and renal tubular acidosis (failure of the kidneys to excrete acid from the blood). He was eventually diagnosed with the CREST variant of scleroderma following the onset of Raynaud’s phenomenon, digital ischemia, nail forked capillary dropout and telangiectasias (dilated small vessels in the skin that cause red spots).
Thus, in clinical situations where new symptoms cannot be explained by a previous diagnosis, further evaluation and consideration of a new diagnosis may be necessary.
Source: The Moisture Seekers, January 2004 European diagnostic criteria for primary Sjögren’s.