Hypokalemia Related to Distal Renal Tubular Acidosis as an Initial Presentation of Primary Sjogren's Syndrome.

Hypokalemia due to loss of potassium through the kidneys can be caused by distal Renal Tubular Acidosis (dRTA). The etiology of dRTA can be primary due to genetic defects or secondary to autoimmune diseases, especially Sjogren's syndrome (SS). The occurrence of dRTA in SS patients is low, at only 5% of cases. This case was interesting because dRTA was the initial clinical manifestation that led to the diagnosis of SS in the patient. A 48-year-old woman came with complaints of recurrent weakness. The patient was routinely hospitalized with severe hypokalemia and received potassium supplementation. The diagnosis of dRTA was based on repeated weakness, normal blood pressure, severe and recurrent hypokalemia, high urinary potassium, alkaline urine, low plasma bicarbonate, and standard anion gap metabolic acidosis. The diagnosis of SS in this patient was confirmed based on dry eyes, dry mouth, positive Schirmer's test, and positive autoantibodies to SS-A and Ro-52. There was a delay in the diagnosis of SS for two years in this patient because the complaints were initially subtle and non-specific. The hypokalemia in this patient was secondary to dRTA associated with primary SS. The possibility of an underlying autoimmune disorder should be considered in a patient presenting with recurrent severe hypokalemia. dRTA, as the etiology of hypokalemia, can be a gateway to the diagnosis of SS. In this patient, complaints related to dRTA appeared before the onset of sicca symptoms, and the diagnosis of SS was established.

Distal renal tubular acidosis presenting with an acute hypokalemic paralysis in an older child with severe vesicoureteral reflux and syringomyelia: a case report.

BACKGROUND: Distal renal tubular acidosis (dRTA) is the most common type of renal tubular acidosis (RTA) in children. Pediatric dRTA is usually genetic and rarely occurs due to acquired issues such as obstructive uropathies, recurrent urinary tract infections (UTIs), and chronic kidney disease (CKD). Although persistent hypokalemia frequently occurs with dRTA, acute hypokalemic paralysis is not frequently reported, especially in older children. CASE PRESENTATION: An eight-year-old girl presented with an acute first episode of paralysis. A physical examination revealed normal vital signs, short stature consistent with her genetic potential, and decreased muscle strength of her upper and lower extremities. Preexisting conditions included stage 4 CKD due to recurrent UTIs, severe vesicoureteral reflux and bilateral hydronephrosis, neurogenic bladder, and multisegment thoracic syringomyelia. Her laboratory work-up revealed hypokalemic, hyperchloremic metabolic acidosis with a normal anion gap. She also had a urine osmolal gap of 1.9 mOsmol/kg with a high urine pH. Intravenous potassium replacement resulted in a complete resolution of her paralysis. She was diagnosed with dRTA and discharged with oral bicarbonate and slow-release potassium supplementation. CONCLUSIONS: This case report highlights the importance of considering dRTA in the differential diagnosis of hypokalemic acute paralysis in children. Additionally, in children with neurogenic lower urinary tract dysfunction and recurrent UTIs, early diagnosis of spinal cord etiology is crucial to treat promptly, slow the progression of CKD, and prevent long-term complications such as RTA.

Osteomalacia caused by atypical renal tubular acidosis with vitamin D deficiency: a case report.

Osteomalacia is a systemic metabolic bone disease. Hypophosphatemia is one of the most important causes of impaired mineralization. Here, we describe a case of osteomalacia associated with atypical renal tubular acidosis. A 43-year-old woman was admitted to our hospital due to sustained unrelieved bilateral flank pain. She had a history of fragile fracture with vitamin D deficiency and had been treated with active vitamin D. On admission, she presented with hypophosphatemia, hypocalcemia, high bone-specific alkaline phosphatase level, bone pain, and low bone mineral density. Multiple areas of uptake were also confirmed by bone scintigraphy, and she was diagnosed with osteomalacia. An increased dose of alfacalcidol was initiated for her vitamin D deficiency; her symptoms remained unstable and unrelieved. Her blood gas examination revealed metabolic acidosis without an increase in the anion gap (HCO3- 11.8 mEq/L, anion gap 3.2 mEq/L). Tubular dysfunction, tubular damage, kidney stones, and inadequate urinary acidification were all observed, suggesting the presence of renal tubular acidosis from a combination of both distal and proximal origin. She also had overt proteinuria, decreased renal function, and hypothalamic hypogonadism. In addition to alfacalcidol, sodium bicarbonate and oral phosphorus supplementation were initiated. After this prescription, her pain dramatically improved in association with the restoration of acid-base balance and electrolytes; renal dysfunction and proteinuria were unaltered. This case indicated that careful assessments of tubular function and acid-base balance are essential for the management of osteomalacia in addition to the evaluation of the calcium/phosphate balance and vitamin D status.

Distal renal tubular acidosis and nephrocalcinosis as initial manifestation of primary sjögren's syndrome.

There is a well-established association between primary Sjögren's syndrome and distal renal tubular acidosis (dRTA). dRTA is a relatively infrequent manifestation of primary Sjögren's syndrome which can present with life-threatening electrolyte abnormalities while, in some patients, it could be the first manifestation of the syndrome. We report the case of a 35-year-old woman who presented with unexplained episodes of generalized weakness, severe hypokalemia, nephrocalcinosis, and normal anion gap metabolic acidosis. Subsequent evaluation revealed primary Sjögren's syndrome as her underlying condition. The patient responded well to potassium supplementation, sodium bicarbonate, and oral prednisolone. After four years of follow-up, there were no other extraglandular manifestations, the renal function remained stable and the acidosis was partially improved without the need for oral bicarbonate. This case demonstrates that dRTA could be the initial manifestation of primary Sjögren's syndrome and highlights the necessity for increased vigilance for patients presenting with persistent hypokalemia or nephrocalcinosis so that an early diagnosis can be made allowing for better control and prevention of disease progression.

Identification of the Causes for Chronic Hypokalemia: Importance of Urinary Sodium and Chloride Excretion.

BACKGROUND: Uncovering the correct diagnosis of chronic hypokalemia with potassium (K+) wasting from the kidneys or gut can be fraught with challenges. We identified clinical and laboratory parameters helpful for differentiating the causes of chronic hypokalemia. METHODS: Normotensive patients referred to our tertiary academic medical center for the evaluation of chronic hypokalemia were prospectively enrolled over 5 years. Clinical features, laboratory examinations-including blood and spot urine electrolytes, acid-base status, biochemistries, and hormones-as well as genetic analysis, were determined. RESULTS: Ninety-nine patients with chronic normotensive hypokalemia (serum K+ 2.8 ± 0.4 mmol/L, duration 4.1 ± 0.9 years) were enrolled. Neuromuscular symptoms were the most common complaints. Although Gitelman syndrome (n = 33), Bartter syndrome (n = 10), and distal renal tubular acidosis (n = 12) were the predominant renal tubular disorders, 44 patients (44%) were diagnosed with anorexia/bulimia nervosa (n = 21), surreptitious use of laxatives (n = 11), or diuretics (n = 12). Patients with gastrointestinal causes and surreptitious diuretics use exhibited a female predominance, lower body mass index, and less K+ supplementation. High urine K+ excretion (transtubular potassium gradient >3, urine K+/Cr >2 mmol/mmol) was universally present in patients with renal tubular disorders, but also found in >50% patients with gastrointestinal causes. Of interest, while urine sodium (Na+) and chloride (Cl-) excretions were high and coupled (urine Na+/Cl- ratio ∼1) in renal tubular disorders and "on" diuretics use, skewed or uncoupled urine Na+ and Cl- excretions were found in anorexia/bulimia nervosa and laxatives abuse (urine Na+/Cl- ratio: 5.0 ± 2.2, 0.4 ± 0.2, respectively) and low urine Na+ and Cl- excretions with fixed Na+/Cl- ratios (0.9 ± 0.2) when "off" diuretics. CONCLUSION: Besides body mass index, sex, and blood acid-base status, integrated interpretation of the urine Na+:Cl- excretion and their ratio is important to make an accurate diagnosis and treatment plan for patients with chronic normotensive hypokalemia.

Hypokalemia and suspected renal tubular acidosis associated with topical carbonic anhydrase inhibitor therapy in a cat.

OBJECTIVE: To describe the occurrence of hypokalemia, metabolic acidosis, and suspected renal tubular acidosis associated with the administration of topical ophthalmic carbonic anhydrase inhibitor (CAI) in a cat. CASE SUMMARY: A 2-year-old, 5.3 kg, male, castrated, domestic short-haired cat developed hyporexia 6 weeks after starting topical ophthalmic dorzolamide 2% therapy for treatment of ocular hypertension. Two weeks later, the cat was evaluated for severe weakness, cervical ventroflexion, and anorexia. Plasma electrolyte and acid-base measurement revealed hypokalemia (K+ = 2.9 mmol/L; reference interval 3.8-5.4 mmol/L) and metabolic acidosis (plasma HCO3- = 9.8 mmol/L; reference interval 15-23 mmol/L) in the presence of a urine pH of 7.5 (reference interval 6.5-7.5). The pH abnormalities were consistent with a renal tubular acidosis. Clinical and biochemical abnormalities resolved with short-term supportive care, potassium supplementation, and discontinuation of dorzolamide therapy. NEW OR UNIQUE INFORMATION PROVIDED: This is the first report of hypokalemia and metabolic acidosis associated with topical CAI therapy in a cat.

Acute-onset paralysis in a patient of rheumatoid arthritis.

Renal tubular acidosis (RTA) is a disorder of renal acidification characterized by inability to acidify urine to pH < 5.5 despite the presence of severe systemic metabolic acidosis and hypokalemia. Hypokalemia leads to acute-onset paralysis and may be a presenting manifestation of RTA. Its association with various autoimmune disease has been reported previously in published reports, but has not been much emphasized. We, hereby, report a case of RTA that presented during the flare of rheumatoid arthritis (RA). A 42-year-old female, a known case of RA for 5 years, presented with persistent joint pain for 1 week and acute-onset quadriparesis for 3 days. Primary investigations revealed hypokalemia with metabolic acidosis. She was managed conservatively with potassium supplements and bicarbonate supplements along with steroids and disease-modifying anti-rheumatic drugs. Such a presentation of renal tubular acidosis in a patient during the flare of rheumatoid arthritis is distinctly rare and previously unreported in published studies.

Etiologic and therapeutic analysis in patients with hypokalemic nonperiodic paralysis.

BACKGROUND: Hypokalemic nonperiodic paralysis represents a group of heterogeneous disorders with a large potassium (K(+)) deficit. Rapid diagnosis of curable causes with appropriate treatment is challenging to avoid the sequelae of hypokalemia. We prospectively analyzed the etiologies and therapeutic characteristics of hypokalemic nonperiodic paralysis. METHODS: Over an 8-year period, patients with hypokalemic nonperiodic paralysis were enrolled by excluding those with hypokalemic periodic paralysis due to acute shift of K(+) into cells. Blood and spot urine samples were collected for the measurements of electrolytes, pH, and biochemistries. Intravenous potassium chloride (KCl) at a rate of 10-20 mmol/h was administered until muscle strength recovered. RESULTS: We had identified 58 patients with hypokalemic nonperiodic paralysis from 208 consecutive patients with hypokalemic paralysis, and their average K(+) concentration was 1.8 ± 0.2 mmol/L. Among patients with low urinary K(+) excretion (n = 17), chronic alcoholism, remote diuretic use, and anorexia/bulimia nervosa were the most common causes. Among patients with high urinary K(+) excretion (n = 41) and metabolic acidosis, renal tubular acidosis and chronic toluene abuse were the main causes, while primary aldosteronism, Gitelman syndrome, and diuretics were the leading diagnoses with metabolic alkalosis. The average KCl dose needed to restore muscle strength was 3.8 ± 0.8 mmol/kg. Initial lower plasma K(+), volume depletion, and high urinary K(+) excretion were associated with higher recovery KCl dosage. During therapy, patients with paradoxical hypokalemia (n = 32) who required more KCl supplementation than patients without (4.1 ± 0.7 vs 3.4 ± 0.7 mmol/kg, P < 0.001) often exhibited significantly higher plasma renin activity and received a higher volume of normal saline before its appearance. CONCLUSIONS: Understanding the common etiologies of hypokalemic nonperiodic paralysis may aid in early diagnosis. Patients with initial lower plasma K(+), renal K(+) wasting, and hypovolemia required higher recovery K(+) dosage. Paradoxical hypokalemia is prone to develop in hypovolemic patients even during K(+) supplementation with volume repletion.

Medullary nephrocalcinosis, distal renal tubular acidosis and polycythaemia in a patient with nephrotic syndrome.

BACKGROUND: Medullary nephrocalcinosis and distal renal tubular acidosis are closely associated and each can lead to the other. These clinical entities are rare in patients with nephrotic syndrome and polycythaemia is an unusual finding in such patients. We describe the presence of medullary nephrocalcinosis, distal renal tubular acidosis and polycythaemia in a patient with nephrotic syndrome due to minimal change disease. Proposed mechanisms of polycythaemia in patients with nephrotic syndrome and distal renal tubular acidosis include, increased erythropoietin production and secretion of interleukin 8 which in turn stimulate erythropoiesis. CASE PRESENTATION: A 22 year old Sri Lankan Sinhala male with nephrotic syndrome due to minimal change disease was investigated for incidentally detected polycythaemia. Investigations revealed the presence of renal tubular acidosis type I and medullary nephrocalcinosis. Despite extensive investigation, a definite cause for polycythaemia was not found in this patient. Treatment with potassium and bicarbonate supplementation with potassium citrate led to correction of acidosis thereby avoiding the progression of nephrocalcinosis and harmful effects of chronic acidosis. CONCLUSION: The constellation of clinical and biochemical findings in this patient is unique but the pathogenesis of erythrocytosis is not clearly explained. The proposed mechanisms for erythrocytosis in other patients with proteinuria include increased erythropoietin secretion due to renal hypoxia and increased secretion of interleukin 8 from the kidney. This case illustrates that there may exist hitherto unknown connections between tubular and glomerular dysfunction in patients with nephrotic syndrome.

[Case of distal renal tubular acidosis complicated with renal diabetes insipidus, showing aggravation of symptoms with occurrence of diabetes mellitus].

We report herein a 27-year-old male case of inherited distal renal tubular acidosis complicated with renal diabetes insipidus, the symptoms of which were aggravated by the occurrence of diabetes mellitus. At 2 months after birth, he was diagnosed as having inherited distal renal tubular acidosis and thereafter supplementation of both potassium and alkali was started to treat his hypokalemia and metabolic acidosis. At the age of 4 years, calcification of the bilateral renal medulla was detected by computed tomography. Subsequently his urinary volume gradually increased and polyuria of approximately 4 L/day persisted. At the age of 27 years, he became fond of sugar-sweetened drinks and also often forgot to take the medicine. He was admitted to our hospital due to polyuria of more than 10 L day, muscle weakness and gait disturbance. Laboratory tests disclosed worsening of both hypokalemia and metabolic acidosis in addition to severe hyperglycemia. It seemed likely that occurrence of diabetes mellitus and cessation of medications can induce osmotic diuresis and aggravate hypokalemia and metabolic acidosis. Consequently, severe dehydration, hypokalemia-induced damage of his urinary concentration ability and enhancement of the renin angiotensin system occurred and thereby possibly worsened his hypokalemia and metabolic acidosis. As normalization of hyperglycemia and metabolic acidosis might have exacerbated hypokalemia further, dehydration and hypokalemia were treated first. Following intensive treatment, these abnormalities were improved, but polyuria persisted. Elevated plasma antidiuretic hormone (12.0 pg/mL) and deficit of renal responses to antidiuretic hormone suggested that the polyuria was attributable to the preexisting renal diabetes insipidus possibly caused by bilateral renal medulla calcification. Thiazide diuretic or nonsteroidal anti-inflammatory drugs were not effective for the treatment of diabetes insipidus in the present case.

Life-threatening hypokalaemic paralysis associated with distal renal tubular acidosis.

A 56-year-old woman developed acute respiratory failure requiring mechanical ventilation due to acute hypokalaemic paralysis. There was no gastrointestinal potassium loss nor was she taking diuretics. Additional analyses revealed a normal anion gap metabolic acidosis with a positive urine anion gap. An acid-load test revealed a renal urine acidification defect, leading to the diagnosis of distal renal tubular acidosis. Normalisation of serum potassium level was established with oral bicarbonate supplementation and temporary potassium supplementation.

Spectrum of hypokalaemic periodic paralysis in a tertiary care centre in India.

BACKGROUND: Acute flaccid paralysis is a common neurological emergency with diverse causes and variable outcome. There is a paucity of reports documenting the spectrum of hypokalaemic paralysis in neurological practice. OBJECTIVE: To report the clinical features, aetiology, and outcome of patients with hypokalaemic paralysis in a tertiary care teaching hospital in India. METHODS: Consecutive patients with acute flaccid paralysis with hypokalaemia from 2008 to 2010 were included in the study. Patients with Guillain-Barré syndrome, porphyria, polio and non-polio enterovirus infection and myositis were excluded. Detailed clinical examination, urinalysis, renal function tests, arterial blood gas analysis, thyroid hormones, and electrocardiogram were carried out. Patients received intravenous or oral potassium supplementation and their underlying causes were treated. RESULTS: Thirty patients aged 17-52 years, including three females, were included. Secondary causes of hypokalaemic paralysis were present in 13 patients and included thyrotoxic paralysis in five and renal tubular acidosis (RTA) and Gitelman syndrome in four each. All the patients had quadriparesis and 10 had severe weakness (MRC grade <2). Tendon reflexes were reduced in eight and brisk in four patients. Respiratory paralysis was present in six patients and one needed artificial ventilation. Fifteen patients had severe hypokalaemia (<2 mmol/l), four had acidosis, and six had alkalosis. The secondary group had more severe hypokalaemia and needed longer time to recover. CONCLUSION: 43.3% of patients with hypokalaemic paralysis had a secondary cause for their condition. Patients with severe hypokalaemia with acidosis or alkalosis should be investigated for secondary causes as their management differ.

Combined renal tubular acidosis and diabetes insipidus in hematological disease.

BACKGROUND: A 39-year-old male with multiple myeloma was admitted for treatment with melphalan and autologous stem cell reinfusion. He presented with hypokalemia and hyperchloremic non-anion-gap metabolic acidosis with a high urinary pH. He also had hypomagnesemia, hypophosphatemia, hypouricemia, proteinuria and glucosuria. The patient subsequently developed polyuria with a low urine osmolality, hypernatremia and, finally, acute renal failure. INVESTIGATIONS: Physical examination, blood and urine analyses, kidney biopsy and tonicity balance. DIAGNOSIS: Fanconi syndrome with proximal (type II) renal tubular acidosis caused by myeloma kidney. Renal tubular acidosis was complicated by probable nephrogenic diabetes insipidus and acute renal failure. MANAGEMENT: Potassium supplementation, sodium bicarbonate therapy, intravenous fluid therapy and dialysis.

Inadequate dietary intake but not renal tubular acidosis is associated with bone demineralization in primary biliary cirrhosis.

BACKGROUND: Metabolic bone disease associated with primary biliary cirrhosis (PBC) is inadequately characterized. Renal tubular acidosis (RTA) may lead to bone loss through chronic mobilization of skeletal calcium salts to buffer increased acid load. AIM: To evaluate the prevalence of RTA in PBC and establish the relationships among bone mineral density (BMD), renal function and nutritional status. METHODS: We enrolled 69 female patients with compensated PBC and 35 control patients with chronic hepatitis C. RTA was searched in all patients, and 24-h dietary recalls were collected at enrolment. BMD was measured by dual-energy X-ray absorptiometry at the femur neck, lumbar spine and radius ultradistalis sites. RESULTS: No patients received a diagnosis of RTA. BMD values (Z-scores) showed only little deviation from normal population with no difference between PBC and controls. Osteopoenic PBC patients (T-score < 1) showed significantly lower daily phosphorus intake [median: 672 (288-1374) vs. 921 (253-1923) mg/day; P = 0.037], with a trend towards lower caloric intake than their nonosteopoenic counterparts. CONCLUSIONS: Renal tubular acidosis is uncommon in compensated PBC. Cholestasis is not associated with an increased risk of bone demineralization. Inadequate dietary intake may be a preventable factor contributing to bone loss in PBC.

Hypokalemic paralysis and osteomalacia secondary to renal tubular acidosis in a case with primary Sjögren's syndrome.

A 39-year-old Japanese woman was admitted to our hospital for severe weakness owing to potassium deficiency caused by type 1 renal tubular acidosis (RTA1). Sicca complex, serological tests, and lip biopsy revealed that she had Sjögren's syndrome (SS). Acidosis was corrected by alkali supplement treatment. She also had an impaired renal function with proteinuria, and high absorbance on Ga scintigram was recognized in both kidneys. She was taking warfarin potassium after aortic valve substitution due to aortic regurgitation, therefore renal biopsy was not performed. Prednisone (20 mg/day) was administered for renal inflammation. One month later, she suffered severe chest wall pains with some local tender points over the costae of both sides, which was presumed to be due to pseudo-fractures based on osteomalacia. Hypokalemic paralysis and osteomalacia should be taken into consideration in the diagnosis of SS with RTA1.

Molecular investigation and long-term clinical progress in Greek Cypriot families with recessive distal renal tubular acidosis and sensorineural deafness due to mutations in the ATP6V1B1 gene.

The spectrum of distal renal tubular acidosis (dRTA) includes a genetically heterogeneous group of inherited conditions of both autosomal-dominant and recessive mode of inheritance. The basic defect is linked to the renal part of acid-base homeostasis, which is partly achieved by the regulated luminal secretion of H+ at the apical surface of the alpha-intercalated cells of renal collecting ducts. This is coupled to bicarbonate reabsorption with chloride counter transport across the basolateral membranes. Here, we describe the molecular findings of the first two Greek Cypriot families with recessive dRTA and the long-term clinical findings in four of five affected members. DNA linkage analysis with four polymorphic markers flanking the ATP6V1B1 gene on chromosome 2 gave evidence for positive linkage; direct DNA analysis by automated DNA sequencing revealed that patients in one family were homozygous for mutation 229+1G>T (IVS7+1G>T) and that patients in the second family were compound heterozygous for 229+1G>T and R157C. The mutations were found on four different haplotypes. Both the mutations were previously reported in patients of Turkish origin. Three known polymorphic variants were also identified. The five patients demonstrated the whole clinical spectrum of the disease including death in infancy, failure to thrive, rickets, nephrocalcinosis, nephrolithiasis, and episodes of hypokalemic paralysis. Some of the family members are now in their mid 30s and late 20s, and nephrolithiasis with recurrent renal colics is their main problem. Renal function has remained normal. In conclusion, early diagnosis in infancy and prompt treatment with alkali and potassium supplements is of great benefit to the patient with dRTA and ensures normal growth. The identification of responsible mutations facilitates antenatal or postnatal diagnosis in concerned families and improves the prognosis.

[Distal renal tubular acidosis as a cause of osteomalacia in a patient with primary Sjögren's syndrome].

BACKGROUND: One half of the patients with primary Sjögren's syndrome has extraglandular manifestations, including renal involvement. The most frequent renal lesion is tubulo-interstitial nephritis, which manifests clinically as distal tubular acidosis and may result in the development of osteomalacia. CASE REPORT: In a 29-year-old female patient, with bilateral nephrolithiasis, the diagnosis of primary Sjögren's syndrome, tubulo-interstitial nephritis, distal renal tubular acidosis, and hypokalemia were established. She was treated for hypokalemia. Two years later she developed bone pains and muscle weakness, she wasn't able to walk, her proximal muscles and pelvic bones were painful, with radiological signs of pelvic bones osteopenia and pubic bones fractures. The diagnosis of osteomalacia was established and the treatment started with Schol's solution, vitamin D and calcium. In the following two months, acidosis was corrected, and the patient started walking. CONCLUSION: In our patient with primary Sjögren's syndrome and interstitial nephritis, osteomalacia was a result of the long time decompensate acidosis, so the correction of acidosis, and the supplementation of vitamin D and calcium were the integral part of the therapy.

Distal renal tubular acidosis associated with large vestibular aqueduct and sensorineural hearing loss.

CONCLUSIONS: Hearing loss and equilibrium dysfunction have different etiologies in patients with large vestibular aqueduct syndrome. We suggest that all children with distal renal tubular acidosis (dRTA) should be subjected to an equilibrium study and audiological evaluation, as well as to a CT or MRI scan. OBJECTIVE: dRTA has been described in association with sensorineural hearing loss, but there are no reported cases that have been examined in detail using audiological and equilibrium studies. We report here a case of progressive sensorineural hearing loss with a large vestibular aqueduct and dRTA, and the results of audiological and equilibrium studies. MATERIAL AND METHODS: A 31-year-old female presented with hearing loss, tinnitus and vertigo. She had been treated with oral sodium citrate, potassium citrate and potassium chloride supplementation because of dRTA since the age of 1 month. RESULTS: The pure-tone audiogram of the patient was off the scale for the right ear and showed progressive sensorineural hearing loss for the left ear. Ice-water caloric testing showed canal paresis on the left side. Temporal bone CT and inner ear MRI revealed a large vestibular aqueduct and a large endolymphatic sac on both sides.

[Hypercalciuria with severe hypocalcaemia in association with distal renal tubular acidosis--case report and differential diagnostics]. / Hiperkalcjuria z ciezka hipokalcemia w przebiegu kwasicy cewkowej dystalnej--opis przypadku i diagnostyka róznicowa.

Neither severe distal renal tubular acidosis nor hypercalciuria have been recognized to cause severe hypocalcaemia. We describe a 53 years old woman with distal renal tubular acidosis and hypercalciuria who demonstrated severe hypocalcemia, normalized after calcium and vitamin D supplementation and treatment with thiazide.

Dosage of potassium citrate in the correction of urinary abnormalities in pediatric distal renal tubular acidosis patients.

Potassium citrate is an alkaline agent that has been recommended for the prevention of nephrolithiasis in distal renal tubular acidosis (RTA). Information on the effectiveness and the optimal dose of potassium citrate in the correction of urinary abnormalities in pediatric distal RTA is limited, however. We conducted this study to determine the effectiveness and the optimal dose of potassium citrate for the correction of urinary abnormalities and the prevention of nephrolithiasis in children with distal RTA. Eight pediatric distal RTA patients participated in this study. The mean +/- SEM age was 9.7 +/- 1.2 years, and mean body weight was 29.1 +/- 4.7 kg. After initial evaluation, all patients were treated with increasing dosages of potassium citrate starting from 2 mEq/kg/d in three divided doses. The dosage was increased progressively in a stepwise fashion every 2 months from 2 mEq/kg/d to 3 mEq/kg/d, then to 4 mEq/kg/d. Blood and 8-hour overnight urine samples were obtained at baseline and every 2 months before increasing the dosage of potassium citrate. Urinary saturations for calcium oxalate and calcium phosphate were estimated by using Tiselius's indices. The basal urinary calcium-to-creatinine, phosphate-to-creatinine, and calcium-to-citrate ratios and urinary saturation for calcium oxalate and calcium phosphate were elevated significantly, whereas citrate-to-creatinine ratio was reduced significantly in distal RTA patients. These ratios were normalized gradually with the increasing dosage of potassium citrate. All the aforementioned abnormalities were normalized only after the dosage of potassium citrate was raised to 4 mEq/kg/d. The elevation in urinary saturation of calcium phosphate could not be normalized throughout the study, however. These results suggest that 4 mEq/kg/d of potassium citrate supplement can correct successfully most of the urinary abnormalities and the elevated urinary saturation for calcium oxalate but not for calcium phosphate in children with distal RTA. Monitoring of urinary calcium-to-creatinine ratio or citrate-to-creatinine ratio is valuable to ensure adequate potassium citrate supplementation in this group of patients.