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The Tohoku Journal of Experimental... Nov 2023We report an infant case of transient distal renal tubular acidosis and Fanconi syndrome caused by rotavirus gastroenteritis. A 10-month-old boy was admitted to the...
We report an infant case of transient distal renal tubular acidosis and Fanconi syndrome caused by rotavirus gastroenteritis. A 10-month-old boy was admitted to the hospital because of frequent vomiting, lack of vitality, and dehydration. He was diagnosed with rotavirus gastroenteritis on account of his positive stool rotavirus antigen test. Although he presented with acidemia and severe mixed metabolic acidosis, he also had a urine pH of 6.0, indicating impaired urinary acidification. Therefore, he was diagnosed with distal renal tubular acidosis. On the third day of hospitalization, a relatively low %tubular reabsorption of phosphate level with hypophosphatemia, increased fractional excretion of uric acid with hypouricemia, and high urinary β2-microglobulin levels were observed. Moreover, he was diagnosed with Fanconi syndrome on account of multiple proximal tubular dysfunctions. After remission of rotavirus gastroenteritis, the signs of renal tubular dysfunction improved. This was a case of rotavirus gastroenteritis-caused transient distal renal tubular acidosis and Fanconi syndrome. Severe metabolic acidosis resulted from anion-gap metabolic acidosis due to acute kidney injury by rotavirus gastroenteritis and normal anion-gap acidosis due to renal tubular acidosis. When renal tubular acidosis is associated with a disease that causes anion-gap metabolic acidosis, mixed metabolic acidosis occurs and becomes exacerbated. Furthermore, it is important to consider the complications of renal tubular acidosis in the case of severe metabolic acidosis.
Topics: Male; Humans; Infant; Acidosis, Renal Tubular; Fanconi Syndrome; Rotavirus; Acidosis; Gastroenteritis; Anions
PubMed: 37635062
DOI: 10.1620/tjem.2023.J070 -
Advances in Rheumatology (London,... Jun 2024Sjögren's disease (SD) is an immune-mediated chronic inflammatory disease that affects epithelial tissues, mainly salivary and lacrimal glands. It also presents...
INTRODUCTION
Sjögren's disease (SD) is an immune-mediated chronic inflammatory disease that affects epithelial tissues, mainly salivary and lacrimal glands. It also presents extraglandular manifestations. The main renal manifestation is tubulointerstitial nephritis (TIN), which can manifest as renal tubular acidosis (RTA). Urinary citrate may be a biomarker of RTA in these patients. The objective of this study was to evaluate whether hypocitraturia is a predictive biomarker of RTA in a sample of patients with SD in a tertiary hospital in southern Brazil.
METHODS
All patients with SD who met the inclusion criteria and who participated in the rheumatology outpatient clinic of the Irmandade Santa Casa de Misericórdia de Porto Alegre were included. Demographic, SD, serological and urinary data were obtained. RTA was considered in those patients who persistently presented urinary pH above 5.5 and serum pH below 7.35. Patients who persistently had urinary pH above 5.5 underwent a urinary acidification test with furosemide and fludrocortisone. These patients received 1 mg of fludrocortisone and 40 mg of furosemide and had their urine samples tested 2, 4 and 6 h after taking the medications. The test was stopped at any urine sample with pH 5.5 or less. The variables were expressed as mean and standard deviation or interquartile range. The association between hypocitraturia and RTA was assessed using the chi-square.
RESULTS
Forty-two patients were included, 95.2% female with a median age of 61.73 years. The prevalence of complete distal RTA was 4.88%. Twenty-eight patients underwent urine acidification testing. Five patients had hypocitraturia, and two of them had complete distal RTA. The association between hypocitraturia and RTA was statistically significant (p < 0.012), with a sensitivity of 100%, specificity of 91.2% and accuracy of 91.7%. The negative predictive value was 100%. The global renal assessment of the population demonstrated two patients with RTA, one patient with decreased renal function and six patients with proteinuria greater than 0.5 g/24 h.
CONCLUSION
The prevalence of RTA in the studied population was 4.88%. Hypocitraturia had high sensitivity and accuracy for the diagnosis of RTA.
Topics: Humans; Acidosis, Renal Tubular; Sjogren's Syndrome; Female; Biomarkers; Middle Aged; Male; Furosemide; Citric Acid; Fludrocortisone; Adult; Hydrogen-Ion Concentration; Aged; Brazil
PubMed: 38831360
DOI: 10.1186/s42358-024-00387-7 -
BMC Nephrology Jul 2023Tubulointerstitial nephritis with IgM-positive plasma cells (IgMPC-TIN) is a newer disease about which there are many unclear points. Glucocorticoid therapy is effective...
BACKGROUND
Tubulointerstitial nephritis with IgM-positive plasma cells (IgMPC-TIN) is a newer disease about which there are many unclear points. Glucocorticoid therapy is effective in many cases of IgMPC-TIN; however, relapse during glucocorticoid tapering has been reported. Relapse and its treatment are poorly defined.
CASE PRESENTATION
Case 1 was a 61-year-old man with renal dysfunction and proteinuria. Tubulointerstitial nephritis and IgM-positive plasma cells were observed in a renal biopsy. He was diagnosed with IgMPC-TIN accompanied by Fanconi syndrome and distal renal tubular acidosis (d-RTA). Prednisolone (PSL; 30 mg daily, 0.45 mg/kg/day) treatment was highly effective, and PSL was gradually tapered and discontinued after 1 year. However, 1 month after PSL discontinuation, therapeutic markers were elevated. Therefore, PSL (10 mg daily, 0.15 mg/kg/day) was administered, and the markers indicated improvement. Case 2 was a 43-year-old woman referred for renal dysfunction and proteinuria. Laboratory data revealed that she had primary biliary cholangitis (PBC), d-RTA, and Fanconi syndrome. A renal biopsy showed accumulation of IgM-positive plasma cells in the tubulointerstitium without any glomerular changes. A diagnosis of IgMPC-TIN was made and the patient was started on PSL (35 mg daily, 0.6 mg/kg/day). Therapeutic markers decreased immediately and PSL was discontinued after 1 year. Three months later, the proteinuria and Fanconi syndrome worsened. PSL treatment was restarted (20 mg daily, 0.35 mg/kg/day) and markers indicated improvement. Case 3 was a 45-year-old woman with renal dysfunction and proteinuria. Tubulointerstitial nephritis and IgM-positive plasma cells were observed in a renal biopsy. The patient had PBC, Sjögren syndrome, d-RTA, and Fanconi syndrome, and the diagnosis of IgMPC-TIN was made. The patient was started on PSL (30 mg daily, 0.4 mg/kg/day) and disease markers decreased immediately. However, when PSL was tapered to 15 mg daily (0.2 mg/kg/day), the patient's serum IgM levels increased; therefore, we maintained the PSL at 15 mg daily (0.2 mg/kg/day).
CONCLUSION
We report three cases of relapsed IgMPC-TIN associated with reduction or discontinuation of glucocorticoid therapy. In these cases, elevation of serum IgM preceded that of other markers such as urinary β-microglobulin, proteinuria, and glycosuria. We recommend monitoring serum IgM levels while tapering glucocorticoids; a maintenance dose of glucocorticoid should be considered if relapse is suspected or anticipated.
Topics: Adult; Female; Humans; Male; Middle Aged; Acidosis, Renal Tubular; Fanconi Syndrome; Glucocorticoids; Immunoglobulin M; Nephritis, Interstitial; Plasma Cells; Proteinuria; Recurrence
PubMed: 37403069
DOI: 10.1186/s12882-023-03253-8 -
Intractable & Rare Diseases Research Aug 2023We performed a study to present a phenotypic and genotypic characterization of a patient clinically diagnosed with carbonic anhydrase II (CAII) deficiency syndrome....
We performed a study to present a phenotypic and genotypic characterization of a patient clinically diagnosed with carbonic anhydrase II (CAII) deficiency syndrome. Medical records were reviewed, and oral examination was performed. Sanger sequencing was undertaken for molecular diagnosis. The patient presented with osteopetrosis, renal tubular acidosis, cerebral calcification, blindness, deafness, and development delay. The oral manifestations included anterior open bite, posterior crossbite, tooth eruption impairment, and hypoplastic amelogenesis imperfecta (AI). Molecular analysis revealed a homozygous deletion (c.753delG, p.Asn252Thrfs*14) and confirmed the clinical diagnosis. This study suggests that AI can be another feature of CAII deficiency syndrome. For the first time, a disease-causing variant is reported to be associated with syndromic AI.
PubMed: 37662627
DOI: 10.5582/irdr.2023.01033 -
Experimental and Therapeutic Medicine Aug 2023Distal renal tubular acidosis (RTA) is a rare adverse reaction to immune checkpoint inhibitors, which only occurs in a small number of cases. To the best of our...
Distal renal tubular acidosis (RTA) is a rare adverse reaction to immune checkpoint inhibitors, which only occurs in a small number of cases. To the best of our knowledge, distal RTA caused by sintilimab, a programmed cell death protein 1 (PD-1) inhibitor, has not been previously reported. In the present study, the case of a 62-year-old man with metastatic cardiac carcinoma treated with sintilimab anti-PD-1 therapy was reported. After the fourth administration of sintilimab, the treatment course was interrupted by metabolic hyperchloraemic acidosis with hypokalaemia. Following urine and blood tests, immunotherapy-induced distal RTA was suspected. Treatment with sintilimab and chemotherapy was stopped, and treatment with sodium bicarbonate and potassium citrate was started, which resulted in an adequate response. The present study provides the first case of distal RTA secondary to sintilimab treatment.
PubMed: 37456171
DOI: 10.3892/etm.2023.12084 -
Journal of the American Society of... Jan 2024In the kidney, the B1 H + -ATPase subunit is mostly expressed in intercalated cells (IC). Its importance in acid-secreting type A ICs is evident in patients with inborn...
SIGNIFICANCE STATEMENT
In the kidney, the B1 H + -ATPase subunit is mostly expressed in intercalated cells (IC). Its importance in acid-secreting type A ICs is evident in patients with inborn distal renal tubular acidosis and ATP6V1B1 mutations. However, the protein is also highly expressed in alkali-secreting non-type A ICs where its function is incompletely understood. We demonstrate in Atp6v1b1 knock out mice that the B1 subunit is critical for the renal response to defend against alkalosis during an alkali load or chronic furosemide treatment. These findings highlight the importance of non-type A ICs in maintaining acid-base balance in response to metabolic challenges or commonly used diuretics.
BACKGROUND
Non-type A ICs in the collecting duct system express the luminal Cl - /HCO 3- exchanger pendrin and apical and/or basolateral H + -ATPases containing the B1 subunit isoform. Non-type A ICs excrete bicarbonate during metabolic alkalosis. Mutations in the B1 subunit (ATP6V1B1) cause distal renal tubular acidosis due to its role in acid secretory type A ICs. The function of B1 in non-type A ICs has remained elusive.
METHODS
We examined the responses of Atp6v1b1-/- and Atp6v1b1+/+ mice to an alkali load and to chronic treatment with furosemide.
RESULTS
An alkali load or 1 week of furosemide resulted in a more pronounced hypokalemic alkalosis in male ATP6v1b1-/- versus Atp6v1b1+/+ mice that could not be compensated by respiration. Total pendrin expression and activity in non-type A ICs of ex vivo microperfused cortical collecting ducts were reduced, and β2 -adrenergic stimulation of pendrin activity was blunted in ATP6v1b1-/- mice. Basolateral H + -ATPase activity was strongly reduced, although the basolateral expression of the B2 isoform was increased. Ligation assays for H + -ATPase subunits indicated impaired assembly of V 0 and V 1 H + -ATPase domains. During chronic furosemide treatment, ATP6v1b1-/- mice also showed polyuria and hyperchloremia versus Atp6v1b1+/+ . The expression of pendrin, the water channel AQP2, and subunits of the epithelial sodium channel ENaC were reduced.
CONCLUSIONS
Our data demonstrate a critical role of H + -ATPases in non-type A ICs function protecting against alkalosis and reveal a hitherto unrecognized need of basolateral B1 isoform for a proper H + -ATPase complexes assembly and ability to be stimulated.
Topics: Humans; Male; Mice; Animals; Acidosis, Renal Tubular; Furosemide; Aquaporin 2; Vacuolar Proton-Translocating ATPases; Kidney; Alkalosis; Sulfate Transporters; Protein Isoforms; Alkalies; Kidney Tubules, Collecting
PubMed: 37990364
DOI: 10.1681/ASN.0000000000000259 -
Nature Communications Jun 2024The renal epithelium is sensitive to changes in blood potassium (K). We identify the basolateral K channel, Kir4.2, as a mediator of the proximal tubule response to K...
The renal epithelium is sensitive to changes in blood potassium (K). We identify the basolateral K channel, Kir4.2, as a mediator of the proximal tubule response to K deficiency. Mice lacking Kir4.2 have a compensated baseline phenotype whereby they increase their distal transport burden to maintain homeostasis. Upon dietary K depletion, knockout animals decompensate as evidenced by increased urinary K excretion and development of a proximal renal tubular acidosis. Potassium wasting is not proximal in origin but is caused by higher ENaC activity and depends upon increased distal sodium delivery. Three-dimensional imaging reveals Kir4.2 knockouts fail to undergo proximal tubule expansion, while the distal convoluted tubule response is exaggerated. AKT signaling mediates the dietary K response, which is blunted in Kir4.2 knockouts. Lastly, we demonstrate in isolated tubules that AKT phosphorylation in response to low K depends upon mTORC2 activation by secondary changes in Cl transport. Data support a proximal role for cell Cl which, as it does along the distal nephron, responds to K changes to activate kinase signaling.
Topics: Animals; Proto-Oncogene Proteins c-akt; Potassium Channels, Inwardly Rectifying; TOR Serine-Threonine Kinases; Signal Transduction; Mice, Knockout; Potassium; Kidney Tubules, Proximal; Mice; Mechanistic Target of Rapamycin Complex 2; Phosphorylation; Male; Chlorides; Mice, Inbred C57BL
PubMed: 38886379
DOI: 10.1038/s41467-024-49562-w -
Cureus Nov 2023A 26-year-old female was hospitalized with acute lower motor neuron quadriplegia. Laboratory tests pointed to the presence of distal renal tubular acidosis, which was...
A 26-year-old female was hospitalized with acute lower motor neuron quadriplegia. Laboratory tests pointed to the presence of distal renal tubular acidosis, which was characterized by hyperchloremic metabolic acidosis, severe hypokalemia, alkaline urine, and a positive urinary anion gap. She also had aminoaciduria, hyperphosphaturia, hypophosphatemia, and normoglycemic glycosuria, all of which are indicative of dysfunction of proximal tubules. Further investigation confirmed Sjogren's syndrome. Strangely, our patient also experienced carpopedal spasms and had low calcium and magnesium levels. As the hypokalemia, hypocalcemia, and acidosis were corrected, the quadriplegia and carpopedal spasm improved. By the time of discharge, proximal tubular abnormalities were rectified (with the exception of albuminuria). One well-known renal symptom of Sjogren's syndrome is distal tubular acidosis. The brief proximal tubular dysfunction and distal tubular acidosis in Sjogren's syndrome is rare. This case report highlights a rare renal complication of Sjogren's syndrome.
PubMed: 38054114
DOI: 10.7759/cureus.48268 -
Oman Medical Journal Jul 2023Distal renal tubular acidosis (RTA) is a common cause of renal stones and nephrocalcinosis in children. Distal RTA can be either acquired or congenital because of a...
Distal renal tubular acidosis (RTA) is a common cause of renal stones and nephrocalcinosis in children. Distal RTA can be either acquired or congenital because of a genetic defect. Tuberous sclerosis complex is an autosomal dominant inherited neurocutaneous syndrome with variable renal involvement. We describe a case of a six-year-old boy with tuberous sclerosis complex who developed distal RTA and renal stones.
PubMed: 37593526
DOI: 10.5001/omj.2023.32 -
JNMA; Journal of the Nepal Medical... Sep 2023Sjogren's syndrome is a rare chronic autoimmune disease characterised by dry eyes and dry mouth due to autoimmune destruction of the lacrimal and salivary glands, which...
UNLABELLED
Sjogren's syndrome is a rare chronic autoimmune disease characterised by dry eyes and dry mouth due to autoimmune destruction of the lacrimal and salivary glands, which can occur concurrently with other autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, or thyroiditis. It can lead to renal complications such as interstitial nephritis and glomerulonephritis, with distal/ type 1 renal tubular acidosis which may result in life-threatening electrolyte imbalance. We present a case of a 35-year-old female who presented with complaints of multiple episodes of muscle weakness. Type 1 renal tubular acidosis was discovered to be the cause of her symptoms which lead to the subsequent diagnosis of Sjogren's syndrome. This is rare presentation of Sjogren's syndrome, and it poses a challenge to diagnosis. Early detection and diagnosis of Sjogren's syndrome might be difficult due to existing diagnostic criteria, which contributes to a higher likelihood of missed diagnosis.
KEYWORDS
case reports; hypokalemia; renal tubular acidosis; Sjogren's syndrome.
Topics: Female; Humans; Adult; Hypokalemia; Sjogren's Syndrome; Acidosis, Renal Tubular; Paralysis; Kidney
PubMed: 38289796
DOI: 10.31729/jnma.8266