Sjögren's syndrome, lymphoproliferation, and renal tubular acidosis

Hypokalemic Paralysis due to Primary Sjögren Syndrome: Case Report and Review of the Literature

Tubulointerstitial nephritis (TIN) is the main renal involvement associated with primary Sjögren syndrome (pSS). TIN can manifest as distal renal tubular acidosis (RTA), nephrogenic diabetes insipidus, proximal tubular dysfunction, and others. We present a 31-year-old female with hypokalemic paralysis due to distal RTA (dRTA). She received symptomatic treatment and hydroxychloroquine with a good response. There is insufficient information on whether to perform a kidney biopsy in these patients or not. The evidence suggests that there is an inflammatory background and therefore a potential serious affection to these patients, such as hypokalemic paralysis. We found 52 cases of hypokalemic paralysis due to dRTA in pSS patients. The majority of those patients were treated only with symptomatic medication. Patients who received corticosteroids had stable evolution even though they did not have another symptomatology. With such heterogeneous information, prospective studies are needed to assess the value of adding corticosteroids as a standardized treatment of this manifestation.

Recurrent Attacks of Hypokalemic Quadriparesis: An Unusual Presentation of Primary Sjögren Syndrome

We herein report the case of a 64-year old woman with recurrent attacks of hypokalemic quadriparesis which resulted from distal renal tubular acidosis (dRTA) secondary to Sjögren syndrome. The patient presented with sudden onset quadriparesis. A physical examination showed symmetric weakness of all four limbs. Severe hypokalemia (1.8 mEq/L), accompanied by normal anion gap metabolic acidosis, a positive urine anion gap and an inappropriately high urine pH pointed toward the diagnosis of dRTA. Further investigations disclosed primary Sjögren syndrome, which had not previously been recognized. On the basis of the current report and a review of the literature we suggest investigating the possibility of Sjögren syndrome in all patients with clinically unexplained dRTA.

Nephrocalcinosis: a rare presenting manifestation of primary Sjögren's syndrome

Renal involvement in primary Sjögren's syndrome (pSS) is not uncommon. Autoimmune tubulointerstitial disorders and distal renal tubular acidosis (dRTA) account for majority of the cases of renal involvement. While dRTA may precede the onset of sicca syndrome in pSS, nephrocalcinosis as a presenting manifestation of pSS is rare. Here, to emphasize the need for initiating investigations for pSS in any patient presenting with nephrocalcinosis due to dRTA, we report a 21-year-old woman presenting with nephrocalcinosis long before pSS was objectively diagnosed.

Induction of Anti-Carbonic-Anhydrase-II Antibody Causes Renal Tubular Acidosis in a Mouse Model of Sjögren’s Syndrome

BACKGROUND/AIM

We recently reported that renal tubular acidosis (RTA) in Sjogren's syndrome (SjS) is associated with high titers of an autoantibody against carbonic anhydrase (CA) II, an important enzyme in renal acid-base regulation. The purpose of this study was to determine whether a CA-II antibody could cause RTA in a mouse model of SjS.

METHODS

PL/J mice were immunized with human CA II to induce CA II antibody formation, whereas controls were injected with phosphate-buffered saline and adjuvant. After 6 weeks, anti-CA-II antibody titers were measured, then ammonium chloride was administered orally for 1 week to detect any acidification defect.

RESULTS

CA-II-immunized mice showed higher anti-CA-II antibody titers than control mice. Pathologically, lymphocytic and plasma cell infiltration was seen in the salivary glands and kidneys of CA-II-immunized mice, but not in controls. On acid loading, blood pH and urine pH decreased in both groups of mice, but the slope of urine pH versus blood pH was less steep in the CA-II-immunized mice, suggesting that these mice had an impaired ability to reduce their urine pH in the face of metabolic acidosis.

CONCLUSION

CA-II-immunized mice had a urinary acidification defect, which may be similar to that seen in patients with SjS.

Serum, urinary, and salivary nitric oxide in rheumatoid arthritis: complexities of interpreting nitric oxide measures

Nitric oxide (NO) may play important roles in rheumatoid arthritis (RA). RA is an inflammatory disease involving joints and other systems including salivary glands. To assess NO production in RA patients, we compared levels of serum, urine, and salivary nitrite and nitrate (NOx) in patients with RA and normal subjects, and we examined the relationships of these measures to disease activity. Serum, urine, and NOx levels as well as renal creatinine, NOx clearance and fractional excretion rates were compared in 25 RA patients and 20 age- and gender-matched healthy controls. Subjects were hospitalized for 3 days and placed on a NOxrestricted diet. NOx was assayed using nitrate reductase and the Griess reagent. RA activity was assessed using standard clinical and laboratory measures. While consuming a restricted diet for 3 days to eliminate the effects of oral intake of NOx, 24 hour urinary NOx excretion decreased in both RA patients and healthy controls. Urine NOx levels at all time points were not significantly different between RA patients and normal subjects. Serum NOx levels also decreased during the 3 days of NOx restriction, but RA patients had higher serum NOx levels at all time points compared with the control group. Likewise, serum NOx/creatinine ratios were higher in RA patients than in controls. Although basal salivary flow rate and tear flow were lower in RA patients, salivary NOx levels did not differ between normal and RA subjects. While renal creatinine clearance was not different between the two groups, we found that RA patients had lower renal NOx clearance and lower renal NOx fractional excretion. After correction of p values for multiple comparisons, there were no significant relationships for the RA group between measures of disease activity and the urinary NOx, serum NOx, or urinary NOx clearance. Despite interest in the use of NO as a marker of disease activity, alterations in renal NOx clearance and fractional excretion in RA make it difficult to assess in vivo NO production even with strict dietary restriction of NOx intake.

A primary Sjögren’s syndrome patient with distal renal tubular acidosis, who presented with symptoms of hypokalemic periodic paralysis

Although renal tubular acidosis (RTA), secondary to autoimmune interstitial nephritis, develops in a large proportion of patients with Sjögren's syndrome (SS), most of the subjects are asymptomatic. Here, we shall present a 39-year-old female patient who came to us with hypokalemic periodic paralysis (HPP), and who was later diagnosed with distal RTA. The patient, who had xerostomia and xerophthalmia for a long period of time, was diagnosed with primary SS from serologic and histologic findings. The patient recovered by being prescribed potassium replacement therapy. Although renal biopsy was not performed, corticosteroids were administered because HPP indicated severe interstitial nephritis. HPP did not reoccur during a 2-year follow-up period. We also review cases with SS-related distal RTA and HPP.

Membranoproliferative glomerulonephritis with primary Sjögren's syndrome

Glomerular involvement in primary Sjögren's syndrome is rare and only five cases of membranoproliferative glomerulonephritis have been reported. We present a case of a 31-year-old white woman with primary Sjögren's syndrome who developed nephrotic syndrome. Evaluation showed no evidence of an associated connective tissue disease. Kidney biopsy was consistent with type I membranoproliferative glomerulonephritis. The patient's nephrotic syndrome resolved spontaneously, a course that has not been reported previously in this setting.

Primary Sjögren's syndrome and gamma heavy chain disease

We describe a patient who has primary Sjögren's syndrome associated with asymptomatic gamma heavy chain disease and a tubulointerstitial nephritis. Sjögren's syndrome is known to be complicated by lymphoproliferative disorders and tubulointerstitial nephritis but gamma heavy chain disease is rare (approximately 100 cases described). There is one previously reported case of gamma heavy chain disease associated with primary Sjögren's syndrome and 2 cases associated with secondary Sjögren's syndrome. Our patient and the 3 other patients described in the literature did not have evidence of an underlying lymphoproliferative disorder.

Renal tubular acidosis in primary Sjögren's syndrome

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.

Viruses and salivary gland disease: are there associations?

Viruses can cause sialadenitis and may be associated with other diseases of salivary glands, particularly immunologically mediated and neoplastic lesions. The evidence that such an association with Sjögren's syndrome is causal is reviewed here and shown to be fairly tenuous at present.

Sjögren's syndrome: clinical and laboratory features, immunopathogenesis, and management

Sjögren's syndrome may be accompanied by local oral problems such as dry mouth, rampant caries, candidosis, or sialadenitis, but it is a systemic autoimmune disorder with wide repercussions, including a small premalignant potential. This article reviews the clinical and immunopathogenic features, as well as the etiology, of Sjögren's syndrome and discusses the diagnosis and management of oral complications.

Hypokalemic paralysis in Sjögren's syndrome secondary to renal tubular acidosis

A 62-year-old woman with Sjögren's syndrome, distal renal tubular acidosis and hypokalemic muscle paralysis is described. The sicca syndrome was nearly subclinical and went unrecognized for several years. The main and first manifestation to be expressed was that of hypokalemic muscle paralysis secondary to renal tubular acidosis. In the last decade several reports have appeared indicating that renal tubular acidosis is associated with Sjögren's syndrome. The data in this report support the view that adult onset distal renal tubular acidosis is often a disorder of an autoimmune disease, frequently that of Sjögren's syndrome. The complications to renal tubular acidosis such as hypokalemic muscle paralysis or chronic muscle weakness, nephrolithiasis, and osteomalacia can be avoided if the diagnosis of renal tubular acidosis is made and corrective alkali therapy is maintained.

Polyclonal hyperviscosity syndrome

The clinical course of two patients who presented with polyclonal hyperviscosity syndrome is described. Polymerizing IgG rheumatoid factors were isolated from the serum of both patients. The presence of these polymers with their extraordinary rheologic properties was the principal determinant of the abnormal rheological properties of the plasma. Neither patient had a discrete rheumatic disease. In both, a lymphoproliferative syndrome was present with features suggestive of the "pseudolymphoma" of Sjögren's syndrome.