Association of Bartter's syndrome with vasculitis

Acquired autoimmune Bartter syndrome in a patient with primary hypothyroidism

We describe an unusual clinical presentation of autoimmune Bartter syndrome in a patient with primary hypothyroidism. A 65-year-old female patient was admitted with neuromuscular weakness associated with hypokalemia and metabolic alkalosis. She had a suboptimal response to potassium supplementation and potassium-sparing diuretic resulting in re-hospitalization with the same symptoms. A detailed serum and urinary biochemistry analysis in the absence of other causes of potassium wasting helped diagnose Bartter syndrome, a rare entity in adults. An autoimmune profile showed anti-Scl-70 antibody to be positive, although she did not develop other systemic features of the disease. Our patient responded to a steroid-based regimen potassium supplement, Indomethacin, and aldosterone antagonist with remarkable resolution of symptoms and correction of electrolyte derangement. We reviewed the literature to search for similar cases and included twenty-seven full-length publications on acquired and autoimmune causes of Bartter syndrome. Our case highlights the fact that hypokalemia with metabolic alkalosis in an adult patient should prompt clinicians to evaluate for common and uncommon conditions. While assessing for abnormal conditions, acquired Bartter syndrome should be considered if a patient has an underlying autoimmune, endocrine, or connective tissue disease.

Association of Adult-Onset Bartter Syndrome With Undifferentiated Connective Tissue Disorder

Bartter syndrome is a rare autosomal recessive, salt-losing disorder characterized by hypokalemic hypochloremic metabolic alkalosis. We are reporting a case of 21 years old patient, who presented with lower limb weakness, marked hypokalemia, proteinuria, and renal impairment detected on laboratory evaluation. The diagnosis of Bartter syndrome was suspected by marked hypokalemia and was supported by renal biopsy which showed evidence of Juxtaglomerular (JG) hyperplasia. This is the first case report about clinicopathological features of the patient with acquired Bartter syndrome and associated undifferentiated connective tissue disorder manifesting as hypokalemia with paralysis.

Cystic Fibrosis Presenting as Pseudo-Bartter Syndrome: An Important Diagnosis that is Missed!

Cystic fibrosis (CF), an autosomal recessive disorder, occurs due to mutations in CFTR gene resulting in impaired cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel function in various epithelia. In addition to the well-known pulmonary and pancreatic morbidities, CF is characterized by electrolyte and acid-base abnormalities- hypochloremia, hyponatremia, hypokalemia and metabolic alkalosis. These are collectively known as Pseudo-Bartter syndrome, as similar abnormalities are seen in Bartter syndrome- an inherited tubulopathy affecting thick ascending limb of loop of Henle. There may be a significant clinical overlap between the Classic Bartter syndrome, Gitelman syndrome and CF presenting as Pseudo-Bartter syndrome, especially in early childhood. This review focuses on Pseudo-Bartter syndrome in CF, its pathogenesis and differentiation from Bartter/Gitelman syndrome. Other causes of metabolic abnormalities resembling Bartter syndrome are also highlighted.

Inherited salt-losing tubulopathies are associated with immunodeficiency due to impaired IL-17 responses

Increased extracellular sodium activates Th17 cells, which provide protection from bacterial and fungal infections. Whilst high salt diets have been shown to worsen autoimmune disease, the immunological consequences of clinical salt depletion are unknown. Here, we investigate immunity in patients with inherited salt-losing tubulopathies (SLT). Forty-seven genotyped SLT patients (with Bartter, Gitelman or EAST Syndromes) are recruited. Clinical features of dysregulated immunity are recorded with a standardised questionnaire and immunological investigations of IL-17 responsiveness undertaken. The effects of altering extracellular ionic concentrations on immune responses are then assessed. Patients are hypokalaemic and hypomagnesaemic, with reduced interstitial sodium stores determined by ²³Na-magnetic resonance imaging. SLT patients report increased mucosal infections and allergic disease compared to age-matched controls. Aligned with their clinical phenotype, SLT patients have an increased ratio of Th2:Th17 cells. SLT Th17 and Tc17 polarisation is reduced in vitro, yet STAT1 and STAT3 phosphorylation and calcium flux following T cell activation are unaffected. In control cells, the addition of extracellular sodium (+40 mM), potassium (+2 mM), or magnesium (+1 mM) reduces Th2:Th17 ratio and augments Th17 polarisation. Our results thus show that the ionic environment typical in SLT impairs IL-17 immunity, but the intracellular pathways that mediate salt-driven Th17 polarisation are intact and in vitro IL-17 responses can be reinvigorated by increasing extracellular sodium concentration. Whether better correction of extracellular ions can rescue the immunophenotype in vivo in SLT patients remains unknown.

Salt levels in culture affect the polarisation of Th17 cells, which normally protect the host from fungal and bacterial infections. Here, the authors study patients with salt-losing tubulopathies (SLT) to find that, while Th17 immunity is dampened in SLT patients, their Th17-inducing signaling pathways are intact and can be reinvigorated by exogenous salt.

Effects of Bartter's syndrome on dentition and dental treatment: A clinical report

Bartter's syndrome is an autosomal recessive form of severe volume depletion due to renal salt wasting. This clinical report describes the prosthodontic treatment for a 24-year-old man who suffers from Bartter's syndrome. The treatment plan included endodontic treatment of the maxillary anterior incisors and placement of cast dowel-and-core restorations because of reduced crown height. The patient's remaining teeth were restored with metal-ceramic crowns.