Renal tubular acidosis in primary Sjögren's syndrome

Abstract

Renal tubular acidosis (RTA) is a frequent extraglandular manifestation of Sjögren's syndrome; however, no distinction on the incidence of this renal tubular defect between primary and secondary Sjögren's syndrome has been reported. This study was undertaken in order to define the frequency of RTA and the possible pathogenetic mechanisms in a group of 21 randomly selected primary Sjögren's syndrome patients. RTA was found in 7 (33%) patients. The incomplete type of the disorder was the most frequent. It seems that the etiology of RTA is multifactorial. Renal excretion of monoclonal proteins and the immunologically-induced interstitial inflammation are the main possible factors of this renal tubular defect.

Decreased Renal Expression of H⁺-ATPase and Pendrin in a Patient with Distal Renal Tubular Acidosis Associated with Sjögren's Syndrome

“…As causes of hereditary distal RTA, many mutations have been identified in the anion exchanger 1, the B1 and a4 subunits of H + -ATPase and cytosolic carbonic anhydrase II leading to the dysfunction of intercalated cells in the collecting tubules (20)(21)(22)(23)(24)(25). The histological findings in the present study were characterized by a prominent interstitial infiltrate composed of mononuclear leukocytes and mild inflammatory cells (26,27). It could be possible that this kind of inflammatory process disrupts the common components of cytoskeleton assembly and regulatory proteins essential for both H + -ATPase and pendrin.…”

Renal Involvement in Primary Sjögren's Syndrome

“…Tubulointerstitial nephritis (TIN) remains the most common presentation of renal involvement in pSS and CD4/CD8 T cell subsets are reported to predominate (27,30). This is often characterized by a distal (type I) renal tubular acidosis (RTA) and less commonly proximal (type II) RTA (Fanconi syndrome) (11,(31)(32)(33). GN is thought to be a rare occurrence, with only case reports available in the literature (10,(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23), and tends to be a late development (34) in the course of the disease.…”

Sjögren's syndrome presenting as hypokalemic periodic paralysis

“…Compared with the patients studied by Pavlidas, Siamopolous, and colleagues (5,6), this subset of patients with primary SS (Table I) appeared to seek medical attention earlier in the course of disease and at a younger average age (36 versus 52 and 50 years, respectively). Renal involvement (symptomatic and asymptomatic) has been estimated to occur in 3040% of SS patients (6). SS patients may have clinical and pathologic evidence of both proximal and distal types of RTA (7,8).…”

“…Our patient exhibited no evidence of proximal RTA, but only distal abnormalities that may have related to her marked hypergammaglobulinemia. The clinical severity of RTA in this group (Table 1) may be a reflection of more extensive renal pathology, as suggested by their lower average creatinine clearance rate than in patients with primary SS and RTA, but without hypokalemic paralysis (57 * 12 muminute versus 83 2 9 ml/minute; P < 0.002) (6). It should be emphasized that our patient had a normal serum creatinine value when she first presented and has not exhibited renal failure over the ensuing 2 years of followup.…”