From Bartter's syndrome to renal tubular acidosis in a patient with Hashimoto's thyroiditis: A case report
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Hashimoto's thyroiditis (HT) is an autoimmune disease that can cause the dysfunction of glands. Moreover, autoimmune disease is an under-recognized cause of several types of tubular dysfunction such as renal tubular acidosis (RTA), Gitelman's syndrome (GS), and Bartter's syndrome (BS). However, the potential mechanism of acquired BS and RTA associated with autoimmune diseases remains unclear. A 55-year-old female patient presented with numbness in both lower extremities for 6 months. She had a 2-year history of HT. Laboratory findings showed hypokalemia, metabolic alkalosis, and elevated plasma aldosterone concentration and renin activity. Urinary analysis revealed renal wasting of potassium, sodium, and chloride. Therefore, she was diagnosed as having HT and secondary BS and was treated with oral methylprednisolone, potassium chloride, and spironolactone. Two weeks later, her serum potassium levels restored to normal. After that, however, the patient was lost to follow-up. Two years later, she was re-hospitalized for progressive muscle weakness and quadriplegia. Laboratory results demonstrated severe hypokalemia, hyperchloremic metabolic acidosis, and inappropriate alkaline urine. Thus, distal RTA (dRTA) was confirmed, and she was prescribed potassium citrate and prednisone, resulting in the correction of hypokalemia and acid-base disturbance within 2 weeks after discharge. We report an HT patient who initially developed hypokalemic metabolic alkalosis and then developed metabolic acidosis within a few years. To our knowledge, this is the first report of two completely opposite acid-base disturbances associated with renal tubular diseases occurring consecutively in the same patient with HT. Our case may provide a valuable clue for exploring the mechanism of renal involvement in autoimmune diseases.

Clinical features and accompanying findings of Pseudo-Bartter Syndrome in cystic fibrosis.

BACKGROUND: Pseudo-Bartter syndrome (PBS) is a rare complication of cystic fibrosis (CF) and there are limited data in the literature about it. We aimed to compare clinical features and accompanying findings of patients with PBS in a large patient population. METHODS: The data were collected from the Cystic Fibrosis Registry of Turkey where 1170 CF patients were recorded in 2017. Clinical features, diagnostic test results, colonization status, complications, and genetic test results were compared in patients with and without PBS. RESULTS: Totally 1170 patients were recorded into the registry in 2017 and 120 (10%) of them had PBS. The mean age of diagnosis and current age of patients were significantly younger and newborn screening positivity was lower in patients with PBS (P < .001). There were no differences between the groups in terms of colonization status, mean z-scores of weight, height, BMI, and mean FEV1 percentage. Types of genetic mutations did not differ between the two groups. Accompanying complications were more frequent in patients without PBS. CONCLUSION: PBS was detected as the most common complication in the registry. It could be due to warm weather conditions of our country. It is usually seen in younger ages regardless of mutation phenotype and it could be a clue for early diagnosis of CF.

Loss of sodium chloride co-transporter impairs the outgrowth of the renal distal convoluted tubule during renal development.

BACKGROUND: Loss-of-function mutations in the sodium chloride (NaCl) co-transporter (NCC) of the renal distal convoluted tubule (DCT) cause Gitelman syndrome with hypokalemic alkalosis, hypomagnesemia and hypocalciuria. Since Gitelman patients are usually diagnosed around adolescence, we tested the idea that a progressive regression of the DCT explains the late clinical onset of the syndrome. METHODS: NCC wild-type and knockout (ko) mice were studied at Days 1, 4 and 10 and 6 weeks after birth using blood plasma analysis and morphological and biochemical methods. RESULTS: Plasma aldosterone levels and renal renin messenger RNA expression were elevated in NCC ko mice during the first days of life. In contrast, plasma ion levels did not differ between genotypes at age 10 days, but a significant hypomagnesemia was observed in NCC ko mice at 6 weeks. Immunofluorescent detection of parvalbumin (an early DCT marker) revealed that the fractional cortical volume of the early DCT is similar for mice of both genotypes at Day 4, but is significantly lower at Day 10 and is almost zero at 6 weeks in NCC ko mice. The DCT atrophy correlates with a marked reduction in the abundance of the DCT-specific Mg2+ channel TRPM6 (transient receptor potential cation channel subfamily M member 6) and an increased proteolytic activation of the epithelial Na+ channel (ENaC). CONCLUSION: After an initial outgrowth, DCT development lags behind in NCC ko mice. The impaired DCT development associates at Day 1 and Day 10 with elevated renal renin and plasma aldosterone levels and activation of ENaC, respectively, suggesting that Gitelman syndrome might be present much earlier in life than is usually expected. Despite an early downregulation of TRPM6, hypomagnesemia is a rather late symptom.

Furosemide-induced tubular dysfunction responding to prostaglandin synthesis inhibitor therapy in a child with nephrotic syndrome.

Furosemide is one of the most common drug used to treat anasarca in childhood nephrotic syndrome. It has minimal side effects on short-term usage, but prolonged use can result in polyuria, hypokalemia and metabolic alkalosis. This pseudo-bartter complication can be treated by discontinuation of the drug with adequate potassium replacement. We report a child who was given furosemide for 20 days elsewhere to treat the edema due to nephrotic syndrome and then presented to us with bartter-like syndrome. Furosemide was discontinued and potassium replacement was initiated. However, the child continued to have polyuria leading to repeated episodes of hypotensive shock. In view of severe symptoms, she was given a short course of oral indomethacin for 6 days, to which she responded. This case highlights the fact that indomethacin can provide symptomatic improvement in furosemide induced pseudo-bartter.

[Poor weight gain, recurrent metabolic alkalosis and hypokalemia in a neonate].

The study reports a female neonate with a gestational age of 29+2 weeks and a birth weight of 1 210 g. Ten minutes after birth, the neonate was admitted to the hospital due to shortness of breath. Several days after birth, the neonate presented with hyperglycemia, polyuria, and poor weight gain, accompanied by azotemia, hypochloremic metabolic alkalosis, hypokalemia, and hyponatremia. Laboratory examinations showed elevated levels of aldosterone, renin, and angiotensin II. Gene detection revealed SLC12A1 gene mutation. Neonatal Bartter syndrome was thus confirmed. The neonate was treated with sodium and potassium supplements, and was followed up for 8 months. During the follow-up, the mental and neural development of the neonate was almost normal at the corrected age, and regular reexaminations showed slight metabolic alkalosis and almost normal electrolyte levels. For the neonates who have the symptoms of unexplainable polyurine and electrolyte disorders, it is important to examine the levels of aldosterone, renin and angiotensin. A definite diagnosis of neonatal Bartter syndrome can be made based on the presence of SLC12A1 gene mutation.

Síndrome de pseudo-Bartter en paciente pediátrico con fibrosis quí­stica estable / Pseudo-Bartter syndrome in stable cystic fibrosis pediatric patient

The pseudo-Bartter´s syndrome (PBS) is a disorder characterized by metabolic alkalosis, hyponatremia, hypochloremia, hypokalemia in the absence of renal tubular disease. The PBS can be one of the complications of cystic fibrosis or may be the initial presentation of the disease in children and adults. The objective is to present a clinical case emphasysing the importance of diagnostic suspicion in cystic fibrosis.

El síndrome de Pseudo-Bartter (SPB) se caracteriza por alcalosis metabólica, hiponatremia, hipocloremia, hipocalemia en ausencia de enfermedad tubular renal. El SPB puede ser una complicación de la Fibrosis Quística (FQ) o la forma de presentación inicial de esta enfermedad, en niños y en adultos. El objetivo es presentar un caso clínico, enfatizando en la importancia de tener un alto índice de sospecha de esta condición.

Effective medical treatment strategies to help cessation of purging behaviors.

OBJECTIVE: Herein we review the major medical issues involved in the "detoxing" of patients who engage in purging behaviors and the pathophysiology of why they occur. METHODS: Given a limited evidence base of randomized controlled trials, we conducted a thorough qualitative review to identify salient literature with regard to the medical issues involved in "detoxing" patients from their purging behaviors. RESULTS: Pseudo Bartter's Syndrome is the root cause of much of the medical difficulties which can arise when purging behaviors are abruptly discontinued. However, this is imminently treatable and even preventable with a judicious medical treatment plan which targets the increased serum aldosterone levels which would otherwise promote salt and water retention and a propensity towards severe edema formation. Effective recommendations are provided which can make this process much less vexing for patients attempting to cease their purging behaviors. CONCLUSIONS: "Detoxing" from purging behaviors can be fraught with medical complications which frustrate these patients and can lead to unsuccessful outcomes. Medical providers should become familiar with the pathophysiology which is the basis for Pseudo Bartter's Syndrome and the effective medical treatments which can lead to a successful outcome.

Pseudo-Bartter's Syndrome in Patients with Cystic Fibrosis: A Case Series and Review of the Literature.

INTRODUCTION: Pseudo-Bartter syndrome (PBS) is characterized by hyponatremic, hypochloremic metabolic alkalosis that mimics Bartter syndrome but with no pathology in the renal tubules. We present five patients with cystic fibrosis (CF) and PBS. CASES OUTLINE: Four children aged between three and five-and-one-half months with previously diagnosed CF and one aged 17 months with previously undiagnosed disease, were hospitalized during the summer season, with severe dehydration, oliguria, apathy and adynamia. Additionally, one of them had an ileostomy due to meconium ileus after birth. All children were on a diet without additional salt intake. Laboratory analysis on admission showed hyponatremia (115-133 mmol/L, mean 122.4 mmol/L), high plasma renin activity (229-500 pg/ml, mean 324 pg/ml) and metabolic alkalosis (pH 7.5-7.6, mean 7.56) in all the patients, and in four of them high blood level of aldosterone (74-560 pg/ml, mean 295.9 pg/ml), hypokalemia (2.3-2.8 mmol/L, mean 2.6 mmol/L), hypochloremia (59-71 mmol/L, mean 66 mmol/L) and low urinary sodium (5-12 mmol/L, mean 9 mmol/L). After intravenous rehydration followed by additional use of sodium and chloride in mean dosis of 1.78 mmol/kg per day, all the patients made a complete recovery. With advice for additional use of salt in the mentioned amount, the patients were discharged from the hospital. CONCLUSION: PBS is one of CF complications, especially in infants and young children in situations accompanied by increased sweating and/or other causes of additional loss of sodium and chlorine. Sometimes, as was the case with one of our patients, PBS may be the initial presentation form of the disease.

A Novel Variant of Bartter's Syndrome.

Bartter's syndrome, a rare disorder affecting the renal tubular potassium handling, is characterized by metabolic alkalosis, hypokalemia and renal salt wasting. Here we describe a patient with Bartter's syndrome with hitherto undescribed clinical features and also discuss the various possibilities leading to such variant of Bartter's syndrome.

Episodic seasonal Pseudo-Bartter syndrome in cystic fibrosis.

Pseudo-Bartter syndrome (PBS) describes an uncommon but well recognised complication of cystic fibrosis leading to hypochloraemic, hypokalaemic metabolic alkalosis. Pseudo-Bartter syndrome is usually seen at initial presentation or within the first two years of life in children with cystic fibrosis. Risk factors for development of PBS include warm weather conditions, severe respiratory or pancreatic disease and gastrointestinal losses (e.g. vomiting and diarrhoea). PBS is rare in older children and adolescents although epidemics have been associated with heat wave conditions in warmer climates. In this era of climate change, it is crucial that clinicians consider Pseudo-Bartter syndrome when patients with cystic fibrosis present unwell during summer.

Bartter syndrome type III and congenital anomalies of the kidney and urinary tract: an antenatal presentation.

Bartter syndrome encompasses a variety of inheritable renal tubular transport disorders characterized by hypokalemia and hypochloremic metabolic alkalosis. Bartter syndrome Type III is caused by genetic alterations in the chloride channel kidney B (CLCNKB) gene and often presents in the first 2 years of life, known as classic Bartter syndrome. However, in rare cases Bartter syndrome Type III has an antenatal presentation with polyhydramnios, premature delivery and severe dehydration in the first weeks of life. Associations between congenital anomalies of the kidney and urinary tract and Bartter syndrome are extremely rare. This case report presents a girl with Bartter syndrome Type III due to a homozygous CLCNKB mutation and bilateral congenital anomalies of the kidney and urinary tract. In addition, we describe the antenatal presentation as well as its perinatal management.

PseudoBartter syndrome in eating disorders.

OBJECTIVE: PseudoBartter's syndrome, a complex pattern of seemingly unrelated metabolic abnormalities, is frequently seen in patients with eating disorders, particularly those who indulge in purging behaviors. We present two cases that, despite divergent background histories and clinical presentations, possess the unifying pathophysiology that ultimately leads to this syndrome. METHOD: Case report and review of literature pertaining to Bartter's and PseudoBartter's syndromes. RESULTS: Purging behaviors commonly result in a state of profound dehydration and chloride depletion that leads to the metabolic abnormalities characteristic of inheritable sodium and chloride renal tubular transport disorders. In the eating disorder patient, these abnormalities lead to a propensity towards marked edema formation. DISCUSSION: The metabolic and clinical manifestations of PseudoBartter's syndrome are seen more commonly than previously thought. It is important to appreciate that a complex self-perpetuating pathophysiology leads to the hypokalemic metabolic alkalosis characteristic of PseudoBartter syndrome. The metabolic abnormalities characteristic of this phenomenon should therefore be viewed in this context and the resulting predilection towards marked edema formation should be borne in mind.

Pseudo-Bartter's syndrome revealing cystic fibrosis in an infant caused by 3849 + 1G>A and 4382delA compound heterozygosity.

UNLABELLED: Pseudo-Bartter's (PB) syndrome characterized by hypokalemic metabolic alkalosis and persistent failure to thrive constitutes a rare typical presentation of cystic fibrosis (CF) with prevalence of 16.8%. We present a case of CF presenting with failure to thrive, dehydration, PB syndrome associated with chest infection and primo-colonization with Pseudomonas aeruginosa. Sweat chloride test was 102 mmol/L. DNA analysis identified 2 mutations 3849 + 1G>A (intron 19) and 4382delA (exon 24) present in heterozygous status. To the best of our knowledge, our case is the first reported case in the literature of CF manifested by PB syndrome associated with chest infection and primo-colonization with Pseudomonas aeruginosa. CONCLUSION: The genotype 3849 + 1G>A/4382delA found in our patient is described for the first time in the literature. It explains the lung involvement with the dehydration and electrolyte disturbances. The role of the mutation in exon 24 in cases of CF with PB syndrome remains to be determined.

Hypokalaemia and failure to thrive: report of a misleading onset.

AIM: We report a case of Gitelman Syndrome (GS) in a 9-year-old girl, previously diagnosed as a Bartter syndrome at one year of life. METHODS: She had been treated with potassium, for over 8 years and was admitted because of fatigue, numbness and weakness of both legs. The patient has typical laboratory findings, including hypokalemia, metabolic alkalosis, hypomagnesemia, and hypocalciuria, thus GS was suspected. RESULTS: Genetic analysis was performed two mutations IVS9(+1)G>T were detected in the thiazide-sensitive Na-Cl cotransporter (TSC) gene (SLC12A3), thus she was diagnosed as having GS. She was treated with oral potassium and magnesium supplements with resolution of the symptoms. CONCLUSION: This case reminded us that doctors should be alert to the initial presentation of renal tubular diseases. Detailed electrolyte analysis, hormone evaluations and clinic follow-up are mandatory for their correct differential diagnosis.

Distal potassium handling based on flow modulation of maxi-K channel activity.

PURPOSE OF REVIEW: Studies on the mechanisms of distal K+ secretion have highlighted the importance of the renal outer-medullary K+ (ROMK) and maxi-K channels. This review considers several human disorders characterized by hypokalemia and hyperkalemia, as well as mouse models of these disorders, and the mechanisms by which ROMK and maxi-K may be dysregulated. RECENT FINDINGS: Analysis of knockout mice lacking ROMK, a model for type II Bartter's syndrome, has shown a role for maxi-K in distal K+ secretion. Knockout mice lacking either the alpha or beta1 subunits of maxi-K also show deficits in flow-dependent K+ secretion. Analysis of transgenic and knock-in mouse models of pseudohypoaldosteronism type II, in which mutant forms of with-no-lysine kinase 4 are expressed, suggests ways in which ROMK and maxi-K may be dysregulated to result in hyperkalemia. Modeling studies also provide insights into the role of Na+ delivery vs. flow in K+ secretion. SUMMARY: The importance of both ROMK and maxi-K to distal K+ secretion is now well established, but the relative role that each of these two channels plays in normal and diseased states has not been definitively established. Analysis of human and animal model data can generate hypotheses for future experiments.

A syndrome resembling Bartter's syndrome in sarcoidosis.

Acquired Bartter-like syndrome, albeit rare, has not been reported to be associated with sarcoidosis. We describe the case of a 32-year-old male patient who presented with progressive muscular weakness of both lower extremities. Profound hypokalaemia associated with renal (K(+)) wasting, bilateral nephrocalcinosis and high plasma renin activity resembled Bartter's syndrome (BS). Both mediastinal lymph node and renal biopsy demonstrated sarcoidosis with non-caseating granuloma. Genetic testing responsible for hereditary BS or Gitelman's syndrome (GS) was negative. Hypokalaemia was well controlled with the administration of spironolactone with oral steroids and KCl. Early recognition and prompt treatment of sarcoidosis-associated Bartter-like syndrome avoids unnecessary complications.

Hyperprostaglandin E syndrome: use of indomethacin and steroid, and death due to necrotizing enterocolitis and sepsis.

Hyperprostaglandin E syndrome (HPS) is the antenatal variant of Bartter syndrome and characterized by polyhydramnios and preterm delivery in the antenatal period and salt-wasting, isosthenuric or hyposthenuric polyuria, hypercalciuria and nephrocalcinosis in the postnatal period. We report a one-month-old infant with HPS with a 15-year-old sister with Bartter syndrome. The infant's birth weight was 2750 g and she had severe dehydration on the 2nd day of life. She had hypercalcemia, hyponatremia, hypokalemia, metabolic alkalosis and elevated plasma renin and aldosterone levels. We instituted indomethacin therapy accompanied by steroid therapy for hypercalcemia. However, the patient developed abdominal distention on the 30th day, which was due to diffuse pneumatosis in sigmoid colon revealed by a subsequent surgical intervention. Following surgery, the patient developed fever, electrolyte abnormalities and subsequently sepsis. The patient died due to sepsis 10 days after surgery. We conclude that indomethacin and steroid therapy must be used cautiously in infants with HPS.

Neonatal pseudo-Bartter syndrome due to maternal eating disorder.

A total of 4 of 153 low birth weight infants at our hospital were found to have pseudo-Bartter syndrome in 2005 and 2006. The neonates (two of whom were twins; light for gestational age 2, appropriate for gestational age 1 and small for gestational age 1) showed symptoms of apnea and/or poor feeding or patent ductus arteriosus, which disappeared by day 4. Hypokalemia, hypochloremia and metabolic alkalosis normalized by day 8. The mothers had repeatedly rushed to the restroom after eating while in hospital, and were lighter at delivery than before pregnancy; however, vomiting was not observed. The mothers had several stress factors related to pregnancy, and all recovered from the eating disorder after delivery. Urinary Cl/creatinine (mequiv. mg(-1)) and serum Mg in the infants were <0.1 and 1.6 to 2.3 mg per 100 ml, respectively. Eating disorder during pregnancy may have caused Bartter-like syndrome and weight loss, and led to the same syndrome and intrauterine growth retardation in the offspring. Therefore, a hidden maternal eating disorder may underlie neonatal pseudo-Bartter syndrome.

Bartter's and Gitelman's syndromes: from gene to clinic.

Bartter's and Gitelman's syndromes are characterized by hypokalemia, normal to low blood pressure and hypochloremic metabolic alkalosis. Recently, investigators have been able to demonstrate mutations of six genes encoding several renal tubular transporters and ion channels that can be held responsible for Bartter's and Gitelman's syndromes. Neonatal Bartter's syndrome is caused by mutations of NKCC2 or ROMK, classic Bartter's syndrome by mutations of ClC-Kb, Bartter's syndrome associated with sensorineural deafness is due to mutations of BSND, Gitelman's syndrome to mutations of NCCT and Bartter's syndrome associated with autosomal dominant hypocalcemia is linked to mutations of CASR. We review the pathophysiology of these syndromes in relation to their clinical presentation.