Unusual Presentation of Polyautoimmunity and Renal Tubular Acidosis in an Adolescent With Hashimoto's Thyroiditis and Central Pontine Myelinolysis

Background: Hashimoto's thyroiditis is frequently associated with other autoimmune diseases and may include renal involvement. Case description: A 17-year-old female with previously diagnosed Hashimoto's thyroiditis and vitiligo was admitted to a pediatric intensive care unit with hypokalemic paralysis and acidosis, after having suffered from recurrent muscular weakness for approximately one year. A few days later she developed central pontine myelinolysis. After initial stabilization she was also diagnosed with distal renal tubular acidosis (dRTA) and tubular proteinuria which can occur in Sjögren's syndrome. Extended screening for autoimmune diseases additionally revealed celiac disease. Treatment with Prednisone and substitution of potassium quickly lead to the resolution of proteinuria and dRTA, but unilateral paralysis of the sixth nerve as a result of central pontine myelinolysis was irreversible. Conclusions: This is the rare case of polyautoimmunity including autoimmune thyroiditis, Sjögren's syndrome, vitiligo and celiac disease in an adolescent with few disease-specific symptoms. The diagnoses were made via a complicating nephritis causing dRTA and proteinuria. Delay in diagnosis lead to permanent neurological damage. This case highlights the need for pediatricians to be aware of rare accompanying diseases and their complications in "common" pediatric autoimmune diseases like Hashimoto's thyroiditis and celiac disease.

Distal renal tubular acidosis and hypokalemic paralysis in a patient with hypothyroidism

A 43- year- old woman on treatment for primary hypothyroidism presented with 1- day progressive weakness of all her limbs and history of similar episodes in the past. Clinical examination revealed grade 2 hyporeflexive weakness. Investigations revealed features of hypokalemia, metabolic acidosis, alkaline urine, and a fractional bicarbonate excretion of 3.5%, consistent with distal renal tubular acidosis. Antithyroid peroxidase and antithroglobulin antibodies were positive, suggesting an autoimmune basis for the pathogenesis of the functional tubular defect. Bicarbonate therapy resulted in a sustained clinical recovery.

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.

Renal tubular acidosis and vasculitis associated with IgE deposits in the kidney and small vessels

We report a woman with a history of allergies, polyuria, polydipsia, proteinuria, renal loss of electrolytes, renal tubular acidosis, nephrocalcinosis, and palpable purpura. A proximal defect was excluded by a normal bicarbonate reabsorption curve, and a distal tubular defect was shown because urine pH did not decrease to less than 6.4 despite ammonium chloride-induced systemic acidosis. Moreover, furosemide failed to improve urinary acidification. Urine-to-blood PCO(2) gradient was less than 14 mm Hg, although the urine bicarbonate level reached values as high as 89 mEq/L. Combining bicarbonate and neutral phosphate infusions increased the urine-to-blood PCO(2) gradient to only 20 mm Hg. These subnormal PCO(2) gradient values point to proton-pump dysfunction in the collecting tubule. Histological evidence of tubulointerstitial disease accompanied the tubular defects. The striking histological feature was the presence of immunoglobulin E (IgE) deposits in glomeruli, tubuli, and vessels. Concurrent with these findings, she had high serum IgE titers and CD23 levels. IgE antibodies from her serum were reactive against human renal tubuli, with binding to two regions that matched two different proteins present in cortex and medulla. One of these proteins corresponded to carbonic anhydrase II (31 kd); the second, to an unidentified protein that seems attached to cell membranes. We suggest that these IgE antibodies could have had a pathogenic role in this patient's glomerular, tubular, and small-vessel disease.

[A young woman with metabolic acidosis and recently discovered IDDM without ketonuria. A rare autoimmune (?) combination of hypothyroidism, diabetes mellitus and distal renal tubular acidosis]

A case of a 29-year-old woman with a multiple autoimmune disorder is reported. She had a history of hypothyroidism since the age of 18. She was admitted to hospital due to hyperglycaemia. At admission she had hyperglycaemia, metabolic acidosis, but no urinary ketone bodies. Further laboratory studies revealed that the acidosis was due to distal renal tubular acidosis rather than diabetic ketoacidosis (although the patient had type 1 diabetes mellitus). Blood tests revealed antibodies to glutamic acid decarboxylase (GAD-65; associated with type 1 diabetes mellitus), thyroid and adrenal tissue, and gastric parietal cells. The patient had not developed pernicious anaemia or Addison's disease. The multiple positive antibody titres in this patient indicate that the diabetes, hypothyroidism and distal renal tubular acidosis are part of an autoimmune syndrome.

Tubulointerstitial nephritis with renal tubular acidosis and asymptomatic primary biliary cirrhosis accompanied by antibody to a 52-kDa mitochondrial protein alone

We report a patient presenting with a mixed type of renal tubular acidosis, who demonstrated anti-mitochondrial antibodies on immunofluorescent study. However, study of anti-M2 antibody (enzyme immunoassay) was negative. Renal biopsy revealed lymphocyte infiltration in the interstitium compatible with chronic tubulointerstitial nephritis. Liver biopsy demonstrated a mild degree of primary biliary cirrhosis (PBC) but biochemical liver function tests were normal, resulting in a diagnosis of asymptomatic PBC. Using affinity chromatography conjugated with the patient's IgG, we purified a 52-kDa protein from a porcine renal mitochondrial fraction. This protein was identified as a component of a mitochondrial multienzyme complex such as dihydrolipoamide acyltransferase of the branched-chain alpha-keto acid dehydrogenase complex (BCKD), based on the molecular mass analysis and partial amino acid sequence of the purified protein. This is the first report of the detection of antibody to 52-kDa mitochondrial protein alone in a patient who showed predominantly tubulointerstitial damage in the kidney rather than liver damage.

Urolithiasis and distal renal tubular acidosis preceding primary Sjögren's syndrome: a retrospective study 5-53 years after the presentation of urolithiasis

OBJECTIVES

Distal renal tubular acidosis (dRTA) can be associated with autoimmune diseases such as primary Sjögren's syndrome (SS). Our objective was to study SS-associated symptoms, autoantibodies and renal histopathology in patients with urolithiasis and dRTA.

SETTING

The patients were from the Departments of Nephrology and Rheumatology. University Hospital of Linköping, which is a tertiary referral hospital, as well as a secondary referral centre for the immediate area around the city of Linköping.

SUBJECTS

Ten female patients with dRTA, who presented with urolithiasis and not with subjective sicca symptoms, were from the Department of Nephrology, University Hospital, Linköping. Autoantibodies were detected in eight of these patients, and they were studied with respect to clinical and laboratory evidence of SS (urolithiasis group). Fifteen women with SS, who presented with sicca symptoms and not with urolithiasis or dRTA, served as the reference group.

RESULTS

In the urolithiasis group, all of the eight patients had anti-SS-A antibodies, and SS (or possible SS) developed in seven of the eight patients 1-48 (mean 15) years after the onset of urolithiasis. Histological features of tubulointerstitial nephritis were found in four of five biopsied patients in the urolithiasis group, and in two of four patients (with dRTA) in the reference group.

CONCLUSIONS

Urolithiasis and dRTA can precede subjective sicca symptoms, and patients with dRTA may have SS in the absence of subjective sicca symptoms. Anti-SS-A antibodies are common in patients with urolithiasis and dRTA. Therefore, we hypothesize the possibility of a Sjögren-related renal disease in these patients.

Hashimoto thyroiditis, distal renal tubular acidosis, pernicious anaemia and encephalopathy: a rare combination of auto-immune disorders in a 12-year-old girl

A case of a 12-year-old girl with a multiple auto-immune disorder is reported. She showed Hashimoto thyroiditis which subsequently developed to hashitoxicosis and distal renal tubular acidosis at 5 years of age, pernicious anaemia at the age of 9 and severe encephalopathy at the age of 12. Laboratory studies revealed very high titres of anti-microsomal and anti-thyroglobulin antibodies and positive gastric parietal cell antibody. As to the encephalopathy, positive oligoclonal IgG bands and high values of IgG index and IgG synthesis ratio in CSF were observed with aggravation of her neurological symptoms. High-dose steroid therapy was effective toward the encephalopathy. Paediatricians should pay careful attention to patients with Hashimoto thyroiditis for association with other autoimmune disorders.

Immune-related potassium-losing interstitial nephritis: a comparison with distal renal tubular acidosis

Six patients with immune-related potassium-losing interstitial nephritis (IRPLIN) are described, and compared with 34 patients with immune-related distal renal tubular acidosis (IRdRTA) and 24 with familial distal renal tubular acidosis (FdRTA). Close similarities were found between IRPLIN and IRdRTA. In our experience, both syndromes are confined to postpubertal women, and are characterized by systemic features of autoimmune disease and a chronic interstitial nephritis which is probably immune-mediated and responsible for the functional tubular defects of the two syndromes. In IRPLIN, a renal potassium-losing state is the main consequence (probably mediated at least in part by renin and aldosterone hypersecretion secondary to renal sodium-losing), and urinary acidification is normal or minimally disturbed; consequently there is no systemic acidosis, and the syndrome is not complicated by nephrocalcinosis or renal bone disease. In IRdRTA, the renal tubular lesion also usually causes potassium depletion, but the most prominent tubular fault is a defect in urinary acidification, which commonly causes metabolic acidosis and often leads to nephrocalcinosis and bone disease. Familial dRTA, in contrast, is equally prevalent in the two sexes and presents at an earlier age than IRPLIN and IRdRTA. Patients with FdRTA and IRdRTA have a similar urinary acidification defect and propensity to acidosis, nephrocalcinosis and bone disease. FdRTA is frequently complicated by renal potassium-losing, but hypokalaemia is less common and less profound than in IRdRTA and IRPLIN, suggesting that immune-related interstitial nephritis has a particular tendency to cause renal potassium-losing.

[A case of Hashimoto's thyroiditis associated with renal tubular acidosis, Sjögren syndrome and empty sella syndrome]

This report describes a 48-year old female patient with Hashimoto's thyroiditis, distal-type renal tubular acidosis (d-RTA), Sjögren syndrome (SjS), and empty sella syndrome (ESS). She has been receiving replacement of thyroxine for Hashimoto's thyroiditis since 1967. She felt muscle weakness and numbness in the extremities and was found to have low serum potassium (2.9 mEq/l) in 1987. Since then she has been administrated potassium chloride orally. She was admitted to our hospital because of recurrence of muscle weakness and numbness of the extremities in November 1990. Laboratory examination revealed that her serum levels of antimicrosomal antibody and anti-thyroglobulin antibody were highly positive (MCHA: x 2(10) x 100, and TGHA: x 100). Furthermore, she was revealed to have 1) d-RTA by oral tolerance tests with the administration of NH4Cl and NaHCO3, 2) SjS by Schirmer test and sialography, and 3) ESS by computed tomography and magnetic resonance imaging examinations of the pituitary. Association of Hashimoto's thyroiditis, d-RTA, SjS and ESS in this case may possibly be caused by common autoimmune mechanism.

[Renal tubular acidosis in primary Sjogren's syndrome: study on the immunology and ultrastructure of EBV]

The related antigens of EBV were examined by McAB against Epstein-Barr virus EAp 138. The related antibody of serous EBV VCA and EBNA of Sjogren's syndrome (SS) patients was examined by indirect immunofluorescence and immunoenzyme methods. EBV was found in the tubular epithelial cells by EM and the relationship between EBV and SS was studied. The results showed that (1) Around the nuclei and basement membrane of the proximal tubular epithelial cells there were positively reacting granules but not in the control group. (2) The related antibody of serous EBV VCA and EBNA showed positive reaction, and the highest titre was VCA-IgA 1:80, VCA-IgM 1:40, VCA-IgG 1:320 and EBNA-IgG 1:320 respectively. In addition, mature granules were found in the cytoplasm of the renal tubular epithelial cells.

A study of immune responses to Tamm-Horsfall glycoprotein in the sera of patients with renal tubular acidosis

Antibody to Tamm-Horsfall glycoprotein in the sera of patients with distal renal tubular acidosis (dRTA) was measured by radioimmunoassay, as well as in samples of normal human serum. Normal human serum contains small amounts of IgG capable of interacting with Tamm-Horsfall glycoprotein. Appropriate assays were carried out on antiserum raised in rabbits against human Tamm-Horsfall glycoprotein serially diluted with normal human serum. Corrections were applied for the presence of interfering substances in serum. The amounts of antibody found in samples of normal and patient sera were not significantly different, although some of the patients were diagnosed as having immune as opposed to familial dRTA. Studies of cell-mediated immunity to Tamm-Horsfall glycoprotein was found not to differentiate between the normal and patient samples. dRTA does not appear to be associated with immune responses to Tamm-Horsfall glycoprotein.

T lymphocyte subsets of the infiltrating cells in the salivary gland and kidney of a patient with Sjögren's syndrome associated with interstitial nephritis

Lymphocyte subsets in the salivary gland and kidney were examined in a 38 years-old female patient with Sjögren's syndrome associated with interstitial nephritis by PAP immunoperoxidase method using monoclonal antibodies. Predominant cells of the infiltrating cells in both tissues were T lymphocytes and most of them were Ia+, OKT4+ cells (activated helper/inducer T lymphocytes). A small number of T lymphocytes were OKT8+ (suppressor/cytotoxic T lymphocytes). Moreover, we found the OKT8+ cells invading the salivary duct epithelial cells. There was no difference in the proportion of lymphocyte subsets of the infiltrating cells between the salivary gland and kidney. A similar pathologic mechanism of tissue damage, therefore, was suggested in both tissues.

Distal renal tubular acidosis and lymphocytic thyroiditis with spontaneously resolving hyperthyroidism. Report of 1 case without nephrocalcinosis

In a 33-year-old woman concurrence of a complete distal renal tubular acidosis (RTA) and lymphocytic thyroiditis with spontaneously resolving hyperthyroidism was observed. Until recently, the rare association of RTA and hyperthyroidism had been thought to be governed by nephrocalcinosis, via hypercalcemia and hypercalciuria. However, in this case, nephrocalcinosis was not present, but there were histological signs of renal interstitial mononuclear cell infiltration, and the RTA persisted despite the resolution of the hyperthyroidism. This observation supports the idea that immunological mechanisms may relate RTA and hyperthyroidism when the latter has an autoimmune origin.

A human autoantibody to renal collecting duct cells associated with thyroid and gastric autoimmunity and possibly renal tubular acidosis

A complement fixing autoantibody reacting with certain renal collecting duct cells, possibly so called dark cells, is described in 113 patients. Clinically, the antibody was strongly associated with thyroid disorders and pernicious anaemia. The patients also showed a markedly increased frequency of thyroid antibodies and antibodies to gastric parietal cells and to intrinsic factor. One of the patients had a distal renal tubular acidosis (RTA) and pernicious anaemia. The antibody was also found in all of three other patients with either latent or manifest RTA. RTA is associated with various immunological diseases, and the renal collecting duct cell antibody may turn out to be a marker of this disorder, either involved in its pathogenesis or representing a secondary phenomenon.

Renal histology and immunopathology in distal renal tubular acidosis

Renal biospy studies are reported from 10 patients with distal renal tubular acidosis (DRTA). On the biopsies from 6 patients who had associated immunological abnormalities immunofluorescent studies for immunoglobulins, complement, and fibrin were performed. Interstitial cellular infiltration and fibrosis were common findings in patients with and without immunological abnormalities, and were usually associated with nephrocalcinosis and/or recurrent urinary infection. No immune deposits were demonstrated in association with the renal tubules. This study shows that DRTA in immunologically abnormal patients is not caused by tubular deposition of antibody or immune complexes. The possibility of cell mediated immune damage is discussed.

Lymphocyte cytotoxicity for kidney cells in renal tubular acidosis of autoimmune liver disease

Sensitisation to a renal tubular antigen, Tamm-Horsfall glycoprotein, has been shown to be common in patients with renal tubular acidosis complicating autoimmune liver disease, and it has been suggested that this immune reaction, by damaging renal tubular cells, might be responsible for the acidification defect. The lymphocytes from 10 out of 13 patients with chronic active hepatitis or primary biliary cirrhosis and an associated renal tubular acidosis were shown to be cytotoxic for a kidney cell line known to secrete Tamm-Horsfall glycoprotein. The cytotoxic reaction was blocked by this antigen, but not by two other proteins, indicating that sensitisation to the renal glycoprotein was the likely cause of the target cell damage. Significant reduction in cytotoxicity after the addition of aggregated IgG suggested that the reaction was of the antibody-dependent cell-mediated type. These results, together with the finding of antigenic material in the surface membrane of liver cells that cross reacts immunologically with Tamm-Horsfall glycoprotein, provide an explanation for the association between chronic liver disease and renal tubular dysfunction.

Renal tubular acidosis in chronic liver disease

Renal tubular acidosis of the gradient or classic type, thought to be due to a disorder of the distal tubule, has been found to occur in 32% of 117 patients with chronic liver disease. Whilst the cause of this disorder is probably multifactorial, immunological mechanisms are considered to play a major role. The presence of this disorder might well be a cause, rather than the result of, the various electrolyte abnormalities seen in patients with chronic liver disease.

Cell-mediated immunity to human Tamm-Horsfall glycoprotein in autoimmune liver disease with renal tubular acidosis

Cell-mediated immune responses to Tamm-Horsfall glycoprotein isolated from human urine were investigated using the leucocyte migration test. Abnormal responses were found in 91% of patients with active chronic hepatitis or primary biliary cirrhosis with an associated renal tubular acidosis (R.T.A.) but in only 19% of those without R.T.A. In nearly all of a group of patients without autoimmune liver disease and in a control group of normal subjects results were within normal limits. In addition, using an immunofluorescent technique with rabbit antibody to human Tamm-Horsfall glycoprotein, it was possible to show the presence in human liver cell membrane of material reacting immunologically as Tamm-Horsfall. These findings suggest that the development of an immune response to this glycoprotein, initiated by release of cross-reacting antigens from damaged hepatocytes, could be the mechanism underlying the occurrence of R.T.A. in some patients with autoimmune liver disease.

Cell-mediated immune responses in chronic liver diseases

Studies of the cell-mediated response to liver antigens, using the leucocyte migration test, in 163 patients with various liver disorders showed that abnormal responses were almost confined to active chronic hepatitis (53% abnormal), primary biliary cirrhosis (64%), and cryptogenic cirrhosis (29%). The test was also abnormal in five out of seven patients with jaundice due to drug hypersensitivity and in one patient with acute infectious hepatitis at a time when mitochondrial antibodies were present in the serum. More of those with active chronic hepatitis on prednisone or azathioprine had normal tests than of those who were untreated, and in 8 out of 10 examined serially during therapy there was an accompanying improvement in leucocyte migration. Abnormal responses to salivary gland or kidney antigens were also found in nearly half of those with features of Sjögren's syndrome or renal tubular acidosis as part of a multisystem involvement-this, though occurring in cryptogenic cirrhosis, was found with greater frequency in active chronic hepatitis and primary biliary cirrhosis. These cell-mediated immune responses, perhaps triggered by the initial damage to the liver from viral or other agents, may be responsible both for the perpetuation of the liver disease and, because of common surface antigens, for the damage to other organs.

Hyperglobulinaemic renal tubular acidosis: a report of nine cases

Of nine women with hyperglobulinaemic renal tubular acidosis four presented with acidosis and five had the "incomplete" form of the disorder. Seven patients had nephrogenic diabetes insipidus, but none had the Fanconi syndrome. Investigation showed abnormal immunoglobulins and autoantibodies in all nine patients. Diseases coexisting with renal tubular acidosis were Sjögren's syndrome, hyperglobulinaemic purpura, autoimmune liver and thyroid disease, diffuse pulmonary fibrosis, and a peripheral neuropathy. It is suggested that this type of renal tubular acidosis might be due to an autoimmune process.

Renal tubular acidosis: an immunopathological study on four patients

Renal biopsies and sera of four patients with distal renal tubular acidosis were examined. The findings consisted of immunoglobulin containing mononuclear cellular infiltrates around the distal tubules, bound immunoglobulin and complement in tubules. The sera of the patients contained antibodies reacting with various tissue antigens, among them renal tubular antigens.

The results suggest that autoimmunity was involved in the pathogenesis of the renal tubular acidosis in these patients.