Evaluating renin and aldosterone levels in children with organic acidemia-therapeutic experience with fludrocortisone.

Hyporeninemic hypoaldosteronism has been reported in only a few cases with methylmalonic acidemia (MMA) and has been attributed to the renal involvement. This study aims to investigate renin-aldosterone levels along with the renal functions of the patients with organic acidemia. This is a cross-sectional study conducted in patients with MMA, propionic acidemia (PA), and isovaleric acidemia (IVA). Serum renin, aldosterone, sodium, and potassium levels were measured, and glomerular filtration rates (GFR) were calculated. Comparisons were made between the MMA and non-MMA (PA+IVA) groups. Thirty-two patients (MMA:PA:IVA = 14:13:5) were included. The median GFR was significantly lower in the MMA group than in the non-MMA group (p < 0.001). MMA patients had the highest incidence of kidney damage (71.4%), followed by PA patients (23%), while none of the IVA patients had reduced GFR. GFR positively correlated with renin levels (p = 0.015, r = 0.433). Although renin levels were significantly lower in the MMA group than the non-MMA group (p = 0.026), no significant difference in aldosterone levels was found between the two groups. Hyporeninemic hypoaldosteronism was found in 3 patients with MMA who had different stages of kidney damage, and fludrocortisone was initiated, which normalized serum sodium and potassium levels.  Conclusions: This study, which has the largest number of patients among the studies investigating the renin-angiotensin system in organic acidemias to date, has demonstrated that hyporeninemic hypoaldosteronism is not a rare entity in the etiology of hyperkalemia in patients with MMA, and the use of fludrocortisone is an effective treatment of choice in selected cases. What is Known: • Hyperkalemia may be observed in cases of methylmalonic acidemia due to renal involvement and can be particularly prominent during metabolic decompensation. • Hyporeninemic hypoaldosteronism has been reported to be associated with hyperkalemia in only a few cases of methylmalonic acidemia. What is New: • Hyporeninemic hypoaldosteronism was found in one-fifth of cases with methylmalonic acidemia. • Fludrocortisone therapy leads to the normalization of serum sodium and potassium levels.

Catch-up Growth and Discontinuation of Fludrocortisone Treatment in Aldosterone Synthase Deficiency.

BACKGROUND: Aldosterone synthase deficiency (ASD) caused by mutations in the CYP11B2 gene is characterized by isolated mineralocorticoid deficiency. Data are scarce regarding clinical and biochemical outcomes of the disease in the follow-up. OBJECTIVE: Assessment of the growth and steroid profiles of patients with ASD at the time of diagnosis and after discontinuation of treatment. DESIGN AND METHOD: Children with clinical diagnosis of ASD were included in a multicenter study. Growth and treatment characteristics were recorded. Plasma adrenal steroids were measured using liquid chromatography-mass spectrometry. Genetic diagnosis was confirmed by CYP11B2 gene sequencing and in silico analyses. RESULTS: Sixteen patients from 12 families were included (8 females; median age at presentation: 3.1 months, range: 0.4 to 8.1). The most common symptom was poor weight gain (56.3%). Median age of onset of fludrocortisone treatment was 3.6 months (range: 0.9 to 8.3). Catch-up growth was achieved at median 2 months (range: 0.5 to 14.5) after treatment. Fludrocortisone could be stopped in 5 patients at a median age of 6.0 years (range: 2.2 to 7.6). Plasma steroid profiles revealed reduced aldosterone synthase activity both at diagnosis and after discontinuation of treatment compared to age-matched controls. We identified 6 novel (p.Y195H, c.1200 + 1G > A, p.F130L, p.E198del, c.1122-18G > A, p.I339_E343del) and 4 previously described CYP11B2 variants. The most common variant (40%) was p.T185I. CONCLUSIONS: Fludrocortisone treatment is associated with a rapid catch-up growth and control of electrolyte imbalances in ASD. Decreased mineralocorticoid requirement over time can be explained by the development of physiological adaptation mechanisms rather than improved aldosterone synthase activity. As complete biochemical remission cannot be achieved, a long-term surveillance of these patients is required.

Hyperkalemia in type 4 renal tubular acidosis associated with systemic lupus erythematosus.

Renal tubular acidosis (RTA) is a normal anion gap metabolic acidosis that manifests with insufficiency of hydrogen ion excretion or bicarbonate (HCO3) reuptake as a result of renal tubular dysfunction independent of glomerular filtration rate. Hypokalemic RTA subtypes co-existing with autoimmune diseases particularly appear in Sjogren's syndrome, but rarely in systemic lupus erythematosus (SLE). Type 4 RTA associated with hyperkalemia is very rare during the course of SLE and hence has been scarcely reported in the literature. Here, we report a 42-year-old patient for whom regular follow-up was ongoing due to class IV lupus nephritis when she developed hyperkalemia. The patient had normal anion gap hyperkalemic metabolic acidosis and her urine pH was 5.5. Type 4 RTA was considered and, therefore, tests for renin and aldosterone levels were requested, which revealed that renin was suppressed and aldosterone was decreased. Upon diagnosis of SLE-associated type 4 RTA, short-term oral HCO3 and fludrocortisone were initiated. Potassium (K) and HCO3 levels improved at day 15 of therapy. In this review, we analyzed our case along with five other reports (a total of seven cases) of SLE-associated type 4 RTA we identified through a literature search. We wanted to highlight RTA for differential diagnosis of hyperkalemia emerging during SLE/lupus nephritis and we also discussed possible underlying mechanisms.

Congenital hyperreninemic hypoaldosteronism due to aldosterone synthase deficiency type I in a Portuguese patient - Case report and review of literature.

Hyperreninemic hypoaldosteronism due to aldosterone synthase (AS) deficiency is a rare condition typically presenting as salt-wasting syndrome in the neonatal period. A one-month-old Portuguese boy born to non-consanguineous parents was examined for feeding difficulties and poor weight gain. A laboratory workup revealed severe hyponatremia, hyperkaliaemia and high plasma renin with unappropriated normal plasma aldosterone levels, raising the suspicion of AS deficiency. Genetic analysis showed double homozygous of two different mutations in the CYP11B2 gene: p.Glu198Asp in exon 3 and p.Val386Ala in exon 7. The patient maintains regular follow-up visits in endocrinology clinics and has demonstrated a favourable clinical and laboratory response to mineralocorticoid therapy. To our knowledge, this is the first Portuguese case of AS deficiency reported with confirmed genetic analysis.

Congenital hyperreninemic hypoaldosteronism due to aldosterone synthase deficiency type I in a Portuguese patient - Case report and review of literature

SUMMARY Hyperreninemic hypoaldosteronism due to aldosterone synthase (AS) deficiency is a rare condition typically presenting as salt-wasting syndrome in the neonatal period. A one-month-old Portuguese boy born to non-consanguineous parents was examined for feeding difficulties and poor weight gain. A laboratory workup revealed severe hyponatremia, hyperkaliaemia and high plasma renin with unappropriated normal plasma aldosterone levels, raising the suspicion of AS deficiency. Genetic analysis showed double homozygous of two different mutations in the CYP11B2 gene: p.Glu198Asp in exon 3 and p.Val386Ala in exon 7. The patient maintains regular follow-up visits in endocrinology clinics and has demonstrated a favourable clinical and laboratory response to mineralocorticoid therapy. To our knowledge, this is the first Portuguese case of AS deficiency reported with confirmed genetic analysis.

Molecular genetic studies in a case series of isolated hypoaldosteronism due to biosynthesis defects or aldosterone resistance.

BACKGROUND AND AIM: Hypoaldosteronism is associated with either insufficient aldosterone production or aldosterone resistance (pseudohypoaldosteronism). Patients with aldosterone defects typically present with similar symptoms and findings, which include failure to thrive, vomiting, hyponatremia, hyperkalemia and metabolic acidosis. Accurate diagnosis of these clinical conditions therefore can be challenging. Molecular genetic analyses can help to greatly clarify this complexity. The aim of this study was to obtain an overview of the clinical and genetic characteristics of patients with aldosterone defects due to biosynthesis defects or aldosterone resistance. DESIGN AND PATIENTS: We investigated the clinical and molecular genetic features of 8 consecutive patients with a clinical picture of aldosterone defects seen in our clinics during the period of May 2015 through October 2017. We screened CYP11B2 for aldosterone synthesis defects and NR3C2 and the three EnaC subunits (SCNN1A, SCNN1B and SCNN1G) for aldosterone resistance. RESULTS: We found 4 novel and 2 previously reported mutations in the genes CYP11B2, NR3C2, SCNN1A and SCNN1G in 9 affected individuals from 7 unrelated families. CONCLUSION: Molecular genetic investigations can help confidently diagnose these conditions and clarify the pathogenicity of aldosterone defects. This study may expand the clinical and genetic correlations of defects in aldosterone synthesis or resistance.

Branchio-oto-renal syndrome presenting with syndrome of hyporeninemic hypoaldosteronism.

Branchio-oto-renal (BOR) syndrome is an autosomal dominant, clinically heterogeneous disorder characterized by branchial arch anomalies, hearing impairment, and renal malformations. We report the case of a 10-year-old boy with BOR syndrome who presented with hyperkalemic hyperchloremic metabolic acidosis due to hyporeninemic hypoaldosteronism. The child also had mental retardation and spastic diplegia which have hitherto not been described in BOR syndrome.

Hyponatremia in an Elderly Patient due to Isolated Hypoaldosteronism Occurring after Licorice Withdrawal.

Hyponatremia is one of the most common electrolyte disorders encountered in the elderly. We present the case of an 81-year-old man who developed hyponatremia due to isolated hypoaldosteronism occurring after licorice withdrawal. He had severe hypokalemia with hypertension and was diagnosed with pseudoaldosteronism. He had been taking a very small dose of licorice as a mouth refresher since his early adulthood. Five months after licorice withdrawal, he developed hypovolemic hyponatremia, which was resolved with administration of fludrocortisone acetate. Our experience with this case suggests that isolated hypoaldosteronism occurring after licorice withdrawal should be considered as a potential cause of hyponatremia in elderly patients.

HYPOALDOSTERONISM IN A MATSCHIE'S TREE KANGAROO (DENDROLAGUS MATSCHIEI).

A 20-yr-old female Matschie's tree kangaroo (Dendrolagus matschiei) was diagnosed with hypoaldosteronism, a rare condition in which the body fails to produce normal amounts of the mineralocorticoid aldosterone. Aldosterone plays a key role in body salt homeostasis, increasing sodium reabsorption and promoting excretion of potassium. Hypoaldosteronism resulted in decreased appetite, lethargy, and weight loss in conjunction with hyponatremia, hyperkalemia, and hypercalcemia in this tree kangaroo. The animal was successfully managed with mineralocorticoid replacement using desoxycorticosterone pivalate. To the authors' knowledge this is the first report of hypoaldosteronism in a tree kangaroo and one of the few reports in the veterinary literature in any species.

Relative hypoaldosteronism in a patient with Wolcott-Rallison syndrome.

BACKGROUND: Wolcott-Rallison syndrome is an autosomal recessive, multisystem disorder with onset of diabetes in the neonatal period or early infancy. CASE REPORT: A 9-year-old girl with diabetes and growth failure from 2 months of age presented with ketoacidosis and multiple organ failure. Evaluation for short stature revealed epiphyseal dysplasia. A homozygous mutation in the EIF2AK3 gene confirmed the clinical diagnosis of Wolcott-Rallison syndrome. She was euthyroid. Biochemical evaluation for potential adrenal dysfunction because of persistently elevated serum potassium (range 5.9-6.3 meq/l) and low serum sodium levels (range 128-130 meq/l) 2 weeks after resolution of ketoacidosis yielded normal findings with respect to basal corticotropin (31 pg/ml) and cortisol (18.7 µg/dl) levels. Estimated GFR-Schwartz (36.9 ml/min/1.73 m(2) ) was consistent with stage 3 chronic renal failure. The transtubular potassium gradient was 1.39 (normal value in hyperkalemic states: > 4.1). The plasma aldosterone (upright: 241.3 pmol/l) was within normal ranges, and plasma renin [39 pg/ml (range 5.41-34.53 pg/ml)] was slightly elevated. The patient was diagnosed as having relative hypoaldosteronism and was started on a sodium-rich diet and low potassium. Failure to respond to the dietary intervention prompted a trial of oral fludrocortisone with subsequent normalization of electrolyte levels. CONCLUSIONS: This is the first case report of Wolcott-Rallison syndrome complicated with relative hypoaldosteronism. Further research is needed to probe the causal inference of relative hypoaldosteronism with chronic renal failure in patients with Wolcott-Rallison syndrome.

Renal tubular acidosis type IV as a complication of lupus nephritis.

Renal tubular acidosis (RTA) is a rare complication of renal involvement of systemic lupus erythematosus (SLE). We describe a 24-year-old male with type IV lupus nephropathy as a presenting manifestation of SLE. He presented with improvement of renal function following induction therapy with three pulses of methylprednisolone and 500 mg biweekly pulses of cyclophosphamide. However, a week after the first pulse of cyclophosphamide, the patient presented with a significant increase in legs edema and severe hyperkalemia. Type IV RTA associated with hyporeninemic hypoaldosteronism was suspected in the presence of metabolic acidosis with a normal anion gap, severe hyperkalemia without worsening renal function, and urinary pH of 5. RTA was confirmed with a transtubular potassium concentration gradient of 2 and low levels of plasma aldosterone, renin, angiotensin II, and cortisol. Intravenous bicarbonate, high-dose furosemide, and fludrocortisone were administered with normalization of potassium levels and renal function.

[Hypoaldosteronism]. / Hipoaldosteronizm.

Hypoaldosteronism is a clinical condition characterized by a deficiency of aldosterone or its impaired action at the tissue level. The disorder may result from disturbances in renal renin production and secretion, conversion of angiotensin I to angiotensin II, adrenal aldosterone synthesis and secretion, or from abnormal responsiveness of the target tissues to aldosterone. Hypoaldosteronism has a wide spectrum of clinical manifestations, ranging from asymptomatic hyperkalemia to life-threatening depletion of fluid volumes. Although the disease, if unrecognized and untreated, seems to be associated with increased morbidity and mortality compared to the normal population, it was surprisingly rarely reviewed in the literature. The aim of this paper is to summarize the present state of knowledge on the etiology, clinical presentation, diagnosis and treatment of various forms of hypoaldosteronism.

[Four cases of aldosterone synthase deficiency in childhood]. / Déficit en aldostérone-synthase : 4 observations pédiatriques.

Neonatal salt-wasting syndromes are rare but potentially serious conditions. Isolated hypoaldosteronism is an autosomal recessive inherited disorder of terminal aldosterone synthesis, leading to selective aldosterone deficiency. Two different biochemical forms of this disease have been described, called aldosterone synthase deficiency or corticosterone methyl oxydase, types I and II. In type I, there is no aldosterone synthase activity and the 18 hydroxycorticosterone (18 OHB) level is low, whereas in type II, a residual activity of aldosterone synthase persists and 18 OHB is overproduced. We report on four patients with isolated hypoaldosteronism. In 2 of them, who were recently diagnosed with aldosterone synthase deficit, we discuss the symptoms and treatment. The 2 other patients are now adults. We discuss the long-term outcome, the quality of adult life, aldosterone synthase deficits, as well as the pathophysiology and molecular analysis.

[Drug-induced exacerbation of hypoaldosteronism in autoimmune polyglandular syndrome type 2]. / Polekowe nasilenie hipoaldosteronizmu w autoimmunologicznym zespole wielogruczolowym typu 2.

Hypoaldosteronism is a clinical condition resulting from inadequate stimulation of aIdosterone secretion (hyporeninemic hypoaIdosteronism), defects in adrenal synthesis of aldosterone (hyperreninemic hypoaldosteronism), or resistance to the peripheral action of this hormone (pseudohypoaldosteronism). The disease is characterized by a wide spectrum of clinical manifestations, ranging from asymptomatic hyperkalemia to life-threatening volume depletion, and, if unrecognized and untreated, it increases morbidity and mortality rates. In this paper, we report a case of a woman diagnosed with autoimmune polyglandular syndrome type 2. As a consequence of adrenal cortex destruction, the patient developed subclinical hypoaldosteronism which was effectively treated with small doses of fludrocortisone. Two and fours years later, she required ibuprofen and atenolol treatment and each of these treatments was accompanied by a transient deterioration in mineralocorticoid activity which resolved after drug withdrawal. This case shows for the first time that drugs reducing plasma renin activity may unmask subclinical hypoaldosteronism in subjects with autoimmune polyglandular syndromes, and that they should be avoided in patients with even small disturbances in the hormonal function of the zona glomerulosa.

Congenital hypoaldosteronism.

Congenital hypoaldosteronism due to an isolated aldosterone biosynthesis defect is rare. We report a 4 month old female infant who presented with failure to thrive, persistent hyponatremia and hyperkalemia. Investigations revealed normal serum 17 hydroxy progesterone and cortisol. A decreased serum aldosterone and serum 18 hydroxy corticosterone levels with a low 18 hydroxy corticosterone: aldosterone ratio was suggestive of corticosterone methyl oxidase type I deficiency. She was started on fludrocortisone replacement therapy with a subsequent normalization of electrolytes. Further molecular analysis is needed to ascertain the precise nature of the mutation.

Life-threatening hypokalaemia on a low-carbohydrate diet associated with previously undiagnosed primary hyperaldosteronism [corrected].

BACKGROUND: Low-carbohydrate diets are popular and fashionable for weight loss despite lack of evidence about long-term effects. Many individuals attempting to lose weight have hypertension, especially those with diabetes, and the prevalence of hyperaldosteronism among hypertensive patients is higher than previously recognized. We present a patient with Type 2 diabetes and previously undiagnosed hyperaldosteronism who developed life-threatening hypokalaemia while following a low-carbohydrate diet. CASE REPORT: A 60-year-old man with diet-treated Type 2 diabetes and hypertension presented with generalized muscle weakness and serum potassium of 1.9 mmol/l. He had succeeded in losing three and a half stones during the previous 4 months by adhering strictly to a low-carbohydrate diet. HbA(1c) was 4.8% and plasma aldosterone:renin ratios were elevated suggestive of increased aldosterone secretion. On a low-calorie mixed diet serum potassium levels were maintained in the low-normal range over the following 165 days. The adrenals were normal on CT scanning and blood pressure responded dramatically to the addition of spironolactone on day 212 (125/83 mmHg). CONCLUSIONS: The prevalence of primary hyperaldosteronism in the hypertensive population, based on elevation of plasma renin:aldosterone ratio, is approximately 6%. The majority of these people are normokalaemic and remain undiagnosed. However, when carbohydrate intake is restricted such individuals are at increased risk of potentially life-threatening metabolic derangements.