due to Òbronchial siccaÓ with decreased bronchial secretions. Other factors may include laryngotracheal reßux. These changes can be observed on bronchoscopy tracheolaryngeal examinations. Symptomatic treatment with room humidiÞers, air puriÞers, and nasal lavage may prove helpful. Belafsky discusses these problems more fully in Chapter 16.

18.4.2Non-specific Interstitial Pneumonitis (NSIP)

SS patients may have interstitial inÞltrates on their chest radiograph that are found incidentally or upon evaluation of dyspnea [24, 25]. Pulmonary function tests have shown abnormalities including a restrictive pattern in small airways and cellular abnormalities in bronchoalveolar lavage ßuid even in patients without respiratory complaints [26, 27]. Long-term prospective controlled studies are needed to determine the clinical course and signiÞcance of these Þndings. However, many of the patients at 5-year follow up will show little progression [28, 29]. Other reports indicate a progressive Þbrotic lung process similar to scleroderma pneumonitis [30]. Thus, we follow SS patients for progression of their inÞltrates on high-resolution CAT scan. In general, our SS population is representative of tertiary referral center and thus a higher percentage of patients have progressive disease. We have treated these SS patients as having NSIP, an entity that now encompasses the previous lymphocytic interstitial pneumonitis (LIP).

Initial therapy with corticosteroids in NSIP and SS has been effective, but the tapering of steroids may lead to relapse.

¥Cyclophosphamide therapy has been reported as useful in SS patients with rapidly progressive NSIP or patients who relapse rapidly when steroids are tapered [31]. However, several of our SS patients have required cyclophosphamide, but it is not possible to determine if we have made any difference in these ÒopenÓ trials. Mycophenolic acid (1 g bid) has also been used in hopes of slowing progression.

¥We need to remember that both alkylator and methotrexate therapy may cause pneumonitis.

¥Sudden deterioration should raise the possibility of intercurrent infection, including atypical mycobacterial infection.

Our approach to therapy has been based on uncontrolled case reports of NSIP in SS that include cyclophosphamide, mycophenolic acid, and cyclosporine [31]. It should be noted that interstitial pneumonitis has been reported after rituximab therapy [32]. Thus, therapies used to treat other manifestations of SS may contribute to the NSIP.

18.5Renal Manifestations

18.5.1 Interstitial Nephritis

ally mild elevation in the plasma creatinine concentration, a relatively benign urinalysis, and abnormalities in tubular function, including the Fanconi syndrome, type 1 (distal) renal tubular acidosis (RTA), nephrogenic diabetes insipidus (tubular resistance to anti-diuretic hormone), and hypokalemia [33, 34]. Anemia may be prominent due to decreased erythropoietin production.

A course of corticosteroids is frequently beneÞcial unless irreversible tubulointerstitial injury has occurred. An improvement in the plasma creatinine concentration should be observed within a few weeks of the initiation of corticosteroids if the damage is reversible. Progression to end-stage renal disease is a rare event [35].

If the symptoms relapse after steroids are tapered, then azathioprine [36] or mycophenolic acid [37] has been suggested. Also, rituximab has been reported to improve nephritis with decrease in severity of renal biopsy [38].

Type 1 renal tubular acidosis [39]ÑA defect in distal acidiÞcation occurs in up to 25% of patients with SjšgrenÕs syndrome. The associated metabolic acidosis is usually mild, but some patients present with a plasma bicarbonate concentration below 10 meq/L and a plasma