1
|
Tangri N, Mathur V, Reaven NL, Funk SE, Whitlock RH, Wesson DE, Bushinsky DA. Association of serum bicarbonate with the development of kidney stones in patients with chronic kidney disease: a retrospective cohort study. Clin Kidney J 2023; 16:1113-1121. [PMID: 37398692 PMCID: PMC10310507 DOI: 10.1093/ckj/sfad034] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Indexed: 11/20/2023] Open
Abstract
BACKGROUND Epidemiological studies demonstrate an association between kidney stones and risk of chronic kidney disease (CKD) and CKD progression. Metabolic acidosis, as a consequence of CKD, results in a reduced urine pH which promotes the formation of some types of kidney stones and inhibits the formation of others. While metabolic acidosis is a risk factor for CKD progression, the association of serum bicarbonate with risk of incident kidney stones is not well understood. METHODS We used an Integrated Claims-Clinical dataset of US patients to generate a cohort of patients with non-dialysis-dependent CKD with two serum bicarbonate values of 12 to <22 mmol/L (metabolic acidosis) or 22 to <30 mmol/L (normal serum bicarbonate). Primary exposure variables were baseline serum bicarbonate and change in serum bicarbonate over time. Cox proportional hazards models evaluated time to first occurrence of kidney stones during a median 3.2-year follow-up. RESULTS A total of 142 884 patients qualified for the study cohort. Patients with metabolic acidosis experienced post-index date kidney stones at greater frequency than patients with normal serum bicarbonate at the index date (12.0% vs 9.5%, P < .0001). Both lower baseline serum bicarbonate [hazard ratio (HR) 1.047; 95% confidence interval (CI) 1.036-1.057] and decreasing serum bicarbonate over time (HR 1.034; 95% CI 1.026-1.043) were associated with increased risk of kidney stone development. CONCLUSIONS Metabolic acidosis was associated with a higher incidence of kidney stones and shorter time to incident stone formation in patients with CKD. Future studies may investigate the role of correcting metabolic acidosis to prevent stone formation.
Collapse
Affiliation(s)
- Navdeep Tangri
- Department of Internal Medicine, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba; Winnipeg, Manitoba, Canada
| | | | | | | | - Reid H Whitlock
- Seven Oaks Hospital Chronic Disease Innovation Centre; Winnipeg, Manitoba, Canada
| | - Donald E Wesson
- Dell Medical School, The University of Texas at Austin, Austin, TX, USA; Donald E Wesson Consulting, LLC, TX, USA
| | | |
Collapse
|
2
|
Díaz-Anadón L, Cardo L, Santos F, Gil-Peña H. Evaluation of urinary acidification in children: Clinical utility. Front Pediatr 2022; 10:1051481. [PMID: 36389372 PMCID: PMC9660234 DOI: 10.3389/fped.2022.1051481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 10/10/2022] [Indexed: 11/13/2022] Open
Abstract
The kidney plays a fundamental role in acid-base homeostasis by reabsorbing the filtered bicarbonate and by generating new bicarbonate, to replace that consumed in the buffering of non-volatile acids, a process that leads to the acidification of urine and the excretion of ammonium (NH4 +). Therefore, urine pH (UpH) and urinary NH4 + (UNH4 +) are valuable parameters to assess urinary acidification. The adaptation of automated plasma NH4 + quantification methods to measure UNH4 + has proven to be an accurate and feasible technique, with diverse potential indications in clinical practice. Recently, reference values for spot urine NH4 +/creatinine ratio in children have been published. UpH and UNH4 +, aside from their classical application in the study of metabolic acidosis, have shown to be useful in the identification of incomplete distal renal tubular acidosis (dRTA), an acidification disorder, without overt metabolic acidosis, extensively described in adults, and barely known in children, in whom it has been found to be associated to hypocitraturia, congenital kidney abnormalities and growth impairment. In addition, a low UNH4 + in chronic kidney disease (CKD) is a risk factor for glomerular filtration decay and mortality in adults, even in the absence of overt metabolic acidosis. We here emphasize on the need of measuring UpH and UNH4 + in pediatric population, establishing reference values, as well as exploring their application in metabolic acidosis, CKD and disorders associated with incomplete dRTA, including growth retardation of unknown cause.
Collapse
Affiliation(s)
- Lucas Díaz-Anadón
- Division of Pediatric Nephrology, Department of Pediatrics, Hospital Universitario Central de Asturias, Oviedo, Asturias, Spain.,Department of Medicine, Faculty of Medicine, University of Oviedo, Oviedo, Asturias, Spain
| | - Leire Cardo
- Clinical Biochemistry Department, Laboratory of Medicine, Hospital Universitario Central de Asturias, Oviedo, Asturias, Spain
| | - Fernando Santos
- Department of Medicine, Faculty of Medicine, University of Oviedo, Oviedo, Asturias, Spain
| | - Helena Gil-Peña
- Division of Pediatric Nephrology, Department of Pediatrics, Hospital Universitario Central de Asturias, Oviedo, Asturias, Spain.,Department of Medicine, Faculty of Medicine, University of Oviedo, Oviedo, Asturias, Spain.,Section of Pediatrics, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Asturias, Spain
| |
Collapse
|
3
|
Sromicki J, Kacl G, Föhl M, Hess B. Prospective long-term evaluation of incomplete distal renal tubular acidosis in idiopathic calcium nephrolithiasis diagnosed by low-dose NH 4CL loading - gender prevalences and impact of alkali treatment. J Nephrol 2022; 35:1619-1626. [PMID: 34973150 PMCID: PMC9300500 DOI: 10.1007/s40620-021-01207-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 11/09/2021] [Indexed: 11/23/2022]
Abstract
Purpose Prospective evaluation of the prevalence of incomplete distal renal tubular acidosis (idRTA) in idiopathic calcium stone formers (ICSF) diagnosed by half-dose ammonium chloride loading (NH4Cl, 0.05 g/kg body weight/day) and impact of alkali treatment of idRTA. Methods Evaluation of 386 consecutive idiopathic calcium stone formers (ICSF) (280 males, 106 females) for idRTA. If screening fasting urine pH was > 5.80, 1-day NH4Cl loading was performed without severe adverse effects. Normally, urine pH falls below 5.45. Results Sixty-four idiopathic calcium stone formers exhibited idRTA, one complete dRTA. Prevalence was higher in women (25.4%) than in men (13.6%). Thus, for more equilibrated comparisons, we formed pairs of 62 idiopathic calcium stone formers (ICSF) with and 62 without idRTA, matched for gender, age, BMI and serum creatinine. Idiopathic calcium stone formers with idRTA more often had hypercalciuria (p < 0.025) and urine citrate < 2 mmol/d (p < 0.05), formed calcium phosphate stones more frequently, exhibited higher numbers of stones/year (1.4 ± 1.5 vs. 0.9 ± 0.8, p = 0.034) and 2.5 times more intrarenal calcifications (4.6 ± 5.9 vs. 1.8 ± 3.6, p = 0.002). All idiopathic calcium stone formers with idRTA were recommended chronic alkali therapy. After 4–15 years of follow-up, stone events /years follow-up (stone passage or urologic intervention) were higher in patients non-adherent to alkali therapy (0.61 ± 0.92) than in patients adherent to treatment (0.11 ± 0.21, p = 0.006). Conclusion Incomplete distal renal tubular acidosis is 1.8-fold more prevalent among female idiopathic calcium stone formers, predicts more stone recurrences, predisposes to calcium phosphate stones and is associated with 2.5 times more intrarenal calcifications vs. non-idRTA patients. Chronic alkali treatment reduces clinical stone recurrences by 5.5 times. Graphical abstract ![]()
Collapse
Affiliation(s)
- Juri Sromicki
- Internal Medicine and Nephrology, Kidney Stone Center Zurich, Klinik Im Park and University of Zurich, Bellariastrasse 38, CH-8038, Zurich, Switzerland.,Department of Cardiac Surgery, University Hospital, Zurich, Switzerland
| | - Georg Kacl
- Internal Medicine and Nephrology, Kidney Stone Center Zurich, Klinik Im Park and University of Zurich, Bellariastrasse 38, CH-8038, Zurich, Switzerland.,Radiology, Klinik Im Park, Zurich, Switzerland
| | - Malin Föhl
- Internal Medicine and Nephrology, Kidney Stone Center Zurich, Klinik Im Park and University of Zurich, Bellariastrasse 38, CH-8038, Zurich, Switzerland
| | - Bernhard Hess
- Internal Medicine and Nephrology, Kidney Stone Center Zurich, Klinik Im Park and University of Zurich, Bellariastrasse 38, CH-8038, Zurich, Switzerland.
| |
Collapse
|
4
|
D'Ambrosio V, Azzarà A, Sangiorgi E, Gurrieri F, Hess B, Gambaro G, Ferraro PM. Results of a Gene Panel Approach in a Cohort of Patients with Incomplete Distal Renal Tubular Acidosis and Nephrolithiasis. Kidney Blood Press Res 2021; 46:469-474. [PMID: 34107482 DOI: 10.1159/000516389] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 04/07/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Distal renal tubular acidosis (dRTA) is characterized by an impairment of urinary acidification resulting in metabolic acidosis, hypokalemia, and inappropriately elevated urine pH. If not treated, this chronic condition eventually leads to nephrocalcinosis, nephrolithiasis, impaired renal function, and bone demineralization. dRTA is a well-defined entity that can be diagnosed by genetic testing of 5 genes known to be disease-causative. Incomplete dRTA (idRTA) is defined as impaired urinary acidification that does not lead to overt metabolic acidosis and therefore can be diagnosed if patients fail to adequately acidify urine after an ammonium chloride (NH4Cl) challenge or furosemide and fludrocortisone test. It is still uncertain whether idRTA represents a distinct entity or is part of the dRTA spectrum and whether it is caused by mutations in the same genes of overt dRTA. METHODS In this cross-sectional study, we investigated a group of 22 stone formers whose clinical features were suspicious of idRTA. They underwent an NH4Cl challenge and were found to have impaired urinary acidification ability. These patients were then analyzed by genetic testing with sequencing of 5 genes: SLC4A1, ATP6V1B1, ATP6V0A4, FOXI1, and WDR72. RESULTS Two unrelated individuals were found to have two different variants in SLC4A1 that had never been described before. CONCLUSIONS Our results suggest the involvement of other genes or nongenetic tubular dysfunction in the pathogenesis of idRTA in stone formers. However, genetic testing may represent a cost-effective tool to recognize, treat, and prevent complications in these patients.
Collapse
Affiliation(s)
- Viola D'Ambrosio
- U.O.S. Terapia Conservativa della Malattia Renale Cronica, U.O.C. Nefrologia, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Università Cattolica del Sacro Cuore, Rome, Italy
| | - Alessia Azzarà
- Istituto di Medicina Genomica, Fondazione Policlinico Universitario A. Gemelli IRCCS - Università Cattolica del Sacro Cuore, Rome, Italy
| | - Eugenio Sangiorgi
- Università Cattolica del Sacro Cuore, Rome, Italy.,Istituto di Medicina Genomica, Fondazione Policlinico Universitario A. Gemelli IRCCS - Università Cattolica del Sacro Cuore, Rome, Italy
| | - Fiorella Gurrieri
- Unità di genetica Medica e Funzionale, Università Campus Bio-Medico, Rome, Italy
| | - Bernhard Hess
- Internal Medicine and Nephrology, Klinik Im Park, Zurich, and University of Zurich, Zurich, Switzerland
| | - Giovanni Gambaro
- Renal Unit, Division of Nephrology and Dialysis, Department of Medicine, University of Verona, Verona, Italy
| | - Pietro Manuel Ferraro
- U.O.S. Terapia Conservativa della Malattia Renale Cronica, U.O.C. Nefrologia, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.,Università Cattolica del Sacro Cuore, Rome, Italy
| |
Collapse
|
5
|
Giglio S, Montini G, Trepiccione F, Gambaro G, Emma F. Distal renal tubular acidosis: a systematic approach from diagnosis to treatment. J Nephrol 2021; 34:2073-2083. [PMID: 33770395 PMCID: PMC8610947 DOI: 10.1007/s40620-021-01032-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 03/16/2021] [Indexed: 12/03/2022]
Abstract
Renal tubular acidosis (RTA) comprises a group of disorders in which excretion of hydrogen ions or reabsorption of filtered HCO3 is impaired, leading to chronic metabolic acidosis with normal anion gap. In the current review, the focus is placed on the most common type of RTA, Type 1 RTA or Distal RTA (dRTA), which is a rare chronic genetic disorder characterized by an inability of the distal nephron to secrete hydrogen ions in the presence of metabolic acidosis. Over the years, knowledge of the molecular mechanisms behind acid secretion has improved, thereby greatly helping the diagnosis of dRTA. The primary or inherited form of dRTA is mostly diagnosed in infancy, childhood, or young adulthood, while the acquired secondary form, as a consequence of other disorders or medications, can happen at any age, although it is more commonly seen in adults. dRTA is not as “benign” as previously assumed, and can have several, highly variable long-term consequences. The present review indeed reports and summarizes both clinical symptoms and diagnosis, long-term outcomes, genetic inheritance, epidemiology and current treatment options, with the aim of shedding more light onto this rare disorder. Being a chronic condition, dRTA also deserves attention in the transition between pediatric and adult nephrology care, and as a rare disease it has a place in the European and Italian rare nephrological diseases network.
Collapse
Affiliation(s)
- Sabrina Giglio
- Medical Genetics Unit, Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy.
| | - Giovanni Montini
- Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Nephrology, Dialysis and PediatricTransplant Unit, Milan, Italy.,Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Francesco Trepiccione
- Department of Translational Medical Sciences, University of Campania "L. Vanvitelli", Naples, Italy.,Biogem Research Institute Ariano Irpino, Ariano Irpino, Italy
| | - Giovanni Gambaro
- Nephrology Department of Medicine, University of Verona, Verona, Italy
| | - Francesco Emma
- Division of Nephrology, Department of Pediatric Subspecialties, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| |
Collapse
|
6
|
Alonso‐Varela M, Gil‐Peña H, Santos F. Incomplete distal renal tubular acidosis in children. Acta Paediatr 2020; 109:2243-2250. [PMID: 32212394 DOI: 10.1111/apa.15269] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 03/08/2020] [Accepted: 03/19/2020] [Indexed: 12/15/2022]
Abstract
AIM To describe incomplete distal renal tubular acidosis (iDRTA) in paediatric patients, a term used for the diagnosis of patients who do not develop spontaneous overt metabolic acidosis but are unable to acidify the urine in response to an ammonium chloride load. METHODS Tests used to explore urinary acidification were revised. In addition, publications in English extracted from 161 entries yielded by a PubMed database search, using 'incomplete distal renal tubular acidosis' as keyword, were reviewed. RESULTS Incomplete distal renal tubular acidosis has mostly been identified in adults with autoimmune diseases, nephrolithiasis, nephrocalcinosis and/or osteopenia. iDRTA has been reported in few paediatric patients with rickets, congenital abnormalities of kidney and urological tract and/or growth failure. The pathophysiological mechanisms potentially responsible for the defect of urinary acidification are discussed as well as the clinical and biochemical findings of iDRTA described in children. CONCLUSION The presentation of iDRTA in children differs from adults. The clinical and biochemical features of iDRTA are not well characterised in paediatric patients. The detection of iDRTA in groups of population such as heterozygous carriers of primary DRTA gene mutations and children with hypocitraturia or hypercalciuria might be of clinical interest to better know the pathophysiology and natural history of iDRTA.
Collapse
Affiliation(s)
- Marta Alonso‐Varela
- Hospital Universitario Cruces Baracaldo, Vizcaya Spain
- University of Oviedo Oviedo Spain
| | | | - Fernando Santos
- University of Oviedo Oviedo Spain
- Hospital Universitario Central de Asturias Oviedo Spain
| |
Collapse
|
7
|
Queiroz DM, Valenzuela RGV, Marinho AWGB, Santos SSBD, Silva DOD, Dias MDS, Cruz LDO. Atypical clinical presentation of distal renal tubular acidosis: a case report registered in Amazonas, Brazil. J Bras Nefrol 2020; 42:380-383. [PMID: 32353105 PMCID: PMC7657058 DOI: 10.1590/2175-8239-jbn-2019-0224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Accepted: 01/30/2020] [Indexed: 11/22/2022] Open
Abstract
We report an unusual case of a 24-year-old girl with a history of recurrent hypokalemic paralysis episodes and skin lesions on the lower limbs and buttocks, both of which had an acute evolution. In subsequent investigations, the patient also had nephrocalcinosis, nephrolithiasis, hyperchloremic metabolic acidosis and persistent alkaline urinary pH. The findings were consistent with distal renal tubular acidosis as the cause of hypokalemic paralysis. Clinical findings, immunological tests and the result of skin biopsy suggested primary Sjögren's syndrome as an underlying cause. The patient developed azotemia due to obstructive nephrolithiasis. All the features presented in this case are an unusual manifestation of distal renal tubular acidosis; so far, we are not aware of a similar report in the literature.
Collapse
|
8
|
Watanabe T. Improving outcomes for patients with distal renal tubular acidosis: recent advances and challenges ahead. PEDIATRIC HEALTH MEDICINE AND THERAPEUTICS 2018; 9:181-190. [PMID: 30588151 PMCID: PMC6296208 DOI: 10.2147/phmt.s174459] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Primary distal renal tubular acidosis (dRTA) is a rare genetic disorder caused by impaired distal acidification due to a failure of type A intercalated cells (A-ICs) in the collecting tubule. dRTA is characterized by persistent hyperchloremia, a normal plasma anion gap, and the inability to maximally lower urinary pH in the presence of systemic metabolic acidosis. Common clinical features of dRTA include vomiting, failure to thrive, polyuria, hypercalciuria, hypocitraturia, nephrocalcinosis, nephrolithiasis, growth delay, and rickets. Mutations in genes encoding three distinct transport proteins in A-ICs have been identified as causes of dRTA, including the B1/ATP6V1B1 and a4/ATP6V0A4 subunits of the vacuolar-type H+-ATPase (H+-ATPase) and the chloride–bicarbonate exchanger AE1/SLC4A1. Homozygous or compound heterozygous mutations in ATP6V1B1 and ATP6V0A4 lead to autosomal recessive (AR) dRTA. dRTA caused by SLC4A1 mutations can occur with either autosomal dominant or AR transmission. Red blood cell abnormalities have been associated with AR dRTA due to SLC4A1 mutations, including hereditary spherocytosis, Southeast Asia ovalocytosis, and others. Some patients with dRTA exhibit atypical clinical features, including transient and reversible proximal tubular dysfunction and hyperammonemia. Incomplete dRTA presents with inadequate urinary acidification, but without spontaneous metabolic acidosis and recurrent urinary stones. Heterozygous mutations in the AE1 or H+-ATPase genes have recently been reported in patients with incomplete dRTA. Early and sufficient doses of alkali treatment are needed for patients with dRTA. Normalized serum bicarbonate, urinary calcium excretion, urinary low-molecular-weight protein levels, and growth rate are good markers of adherence to and/or efficacy of treatment. The prognosis of dRTA is generally good in patients with appropriate treatment. However, recent studies showed an increased frequency of chronic kidney disease (CKD) in patients with dRTA during long-term follow-up. The precise pathogenic mechanisms of CKD in patients with dRTA are unknown.
Collapse
Affiliation(s)
- Toru Watanabe
- Department of Pediatrics, Niigata City General Hospital, Niigata City 950-1197, Japan,
| |
Collapse
|
9
|
Abstract
Renal tubular acidosis (RTA) is comprised of a diverse group of congenital or acquired diseases with the common denominator of defective renal acid excretion with protean manifestation, but in adults, recurrent kidney stones and nephrocalcinosis are mainly found in presentation. Calcium phosphate (CaP) stones and nephrocalcinosis are frequently encountered in distal hypokalemic RTA type I. Alkaline urinary pH, hypocitraturia, and, less frequently, hypercalciuria are the tripartite lithogenic factors in distal RTA (dRTA) predisposing to CaP stone formation; the latter 2 are also commonly encountered in other causes of urolithiasis. Although the full blown syndrome is easily diagnosed by conventional clinical criteria, an attenuated forme fruste called incomplete dRTA typically evades clinical testing and is only uncovered by provocative acid-loading challenges. Stone formers (SFs) that cannot acidify urine of pH < 5.3 during acid loading are considered to have incomplete dRTA. However, urinary acidification capacity is not a dichotomous but rather a continuous trait, so incomplete dRTA is not a distinct entity but may be one end of a spectrum. Recent findings suggest that incomplete dRTA can be attributed to heterozygous carriers of hypofunctional V-ATPase. The value of incomplete dRTA diagnosis by provocative testing and genotyping candidate genes is a valuable research tool, but it remains unclear at the moment whether they alter clinical practice and needs further clarification. No randomized controlled trials have been performed in SFs with dRTA or CaP stones, and until such data are available, treatment of CaP stones are centered on reversing the biochemical abnormalities encountered in the metabolic workup. SFs with type I dRTA should receive alkali therapy, preferentially in the form of K-citrate delivered judiciously to treat the chronic acid retention that drives both stone formation and bone disease.
Collapse
|
10
|
Renal Evaluation in Common Variable Immunodeficiency. J Immunol Res 2018; 2018:5841031. [PMID: 29736405 PMCID: PMC5874972 DOI: 10.1155/2018/5841031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 12/21/2017] [Accepted: 01/08/2018] [Indexed: 12/18/2022] Open
Abstract
Introduction Common variable immunodeficiency (CVID) comprises a heterogeneous group of disorders characterized by impaired antibody production. Kidney involvement in CVID is described in isolated and sporadic case reports. The objective of this study was to study the renal function pattern in CVID patients through glomerular and tubular function tests. Methods Study of 12 patients with CVID diagnosis and 12 healthy control individuals. Glomerular filtration rate (GFR), fractional excretion of sodium (FENa+) and potassium (FEK+), urinary concentration, and acidification capacity were measured. In addition, microalbuminuria and urinary monocyte chemoattractant protein-1 (MCP-1) were evaluated as markers of selectivity of the glomerular barrier and inflammation, respectively. Results In relation to glomerular markers, all CVID patients had normal GFR (>90 mL/min/1.73 m2), and microalbuminuria and urinary MCP-1 levels were also similar to those of controls. Interestingly, CVID patients had reduced urinary concentration capacity, as demonstrated by lower U/POsm ratio, when compared to controls. Also, while all control subjects achieved a urinary pH less than 5.3, no CVID patients showed a decrease in urinary pH to such levels in response to acid loading with CaCl2, characterizing impaired urinary acidification capacity. Conclusion Patients showed a trend towards an elevated prevalence of tubular dysfunction, mainly related to urinary acidification and concentration capacities.
Collapse
|
11
|
Dhayat NA, Gradwell MW, Pathare G, Anderegg M, Schneider L, Luethi D, Mattmann C, Moe OW, Vogt B, Fuster DG. Furosemide/Fludrocortisone Test and Clinical Parameters to Diagnose Incomplete Distal Renal Tubular Acidosis in Kidney Stone Formers. Clin J Am Soc Nephrol 2017; 12:1507-1517. [PMID: 28775126 PMCID: PMC5586565 DOI: 10.2215/cjn.01320217] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Accepted: 05/12/2017] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Incomplete distal renal tubular acidosis is a well known cause of calcareous nephrolithiasis but the prevalence is unknown, mostly due to lack of accepted diagnostic tests and criteria. The ammonium chloride test is considered as gold standard for the diagnosis of incomplete distal renal tubular acidosis, but the furosemide/fludrocortisone test was recently proposed as an alternative. Because of the lack of rigorous comparative studies, the validity of the furosemide/fludrocortisone test in stone formers remains unknown. In addition, the performance of conventional, nonprovocative parameters in predicting incomplete distal renal tubular acidosis has not been studied. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We conducted a prospective study in an unselected cohort of 170 stone formers that underwent sequential ammonium chloride and furosemide/fludrocortisone testing. RESULTS Using the ammonium chloride test as gold standard, the prevalence of incomplete distal renal tubular acidosis was 8%. Sensitivity and specificity of the furosemide/fludrocortisone test were 77% and 85%, respectively, yielding a positive predictive value of 30% and a negative predictive value of 98%. Testing of several nonprovocative clinical parameters in the prediction of incomplete distal renal tubular acidosis revealed fasting morning urinary pH and plasma potassium as the most discriminative parameters. The combination of a fasting morning urinary threshold pH <5.3 with a plasma potassium threshold >3.8 mEq/L yielded a negative predictive value of 98% with a sensitivity of 85% and a specificity of 77% for the diagnosis of incomplete distal renal tubular acidosis. CONCLUSIONS The furosemide/fludrocortisone test can be used for incomplete distal renal tubular acidosis screening in stone formers, but an abnormal furosemide/fludrocortisone test result needs confirmation by ammonium chloride testing. Our data furthermore indicate that incomplete distal renal tubular acidosis can reliably be excluded in stone formers by use of nonprovocative clinical parameters.
Collapse
Affiliation(s)
- Nasser A. Dhayat
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | - Michael W. Gradwell
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | - Ganesh Pathare
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
- Swiss National Centre of Competence in Research TransCure, University of Bern, Bern, Switzerland
| | - Manuel Anderegg
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
- Swiss National Centre of Competence in Research TransCure, University of Bern, Bern, Switzerland
| | - Lisa Schneider
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | - David Luethi
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | - Cedric Mattmann
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | - Orson W. Moe
- Departments of Internal Medicine and Physiology, and the Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Bruno Vogt
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
| | - Daniel G. Fuster
- Division of Nephrology and Hypertension, Bern University Hospital, Bern, Switzerland
- Swiss National Centre of Competence in Research TransCure, University of Bern, Bern, Switzerland
| |
Collapse
|
12
|
Goldfarb DS. Refining Diagnostic Approaches in Nephrolithiasis: Incomplete Distal Renal Tubular Acidosis. Clin J Am Soc Nephrol 2017; 12:1380-1382. [PMID: 28775128 PMCID: PMC5586576 DOI: 10.2215/cjn.07160717] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- David S Goldfarb
- Nephrology Division, New York Harbor Department of Veterans Affairs Medical Center, New York, New York; and Nephrology Division, New York University School of Medicine, New York, New York
| |
Collapse
|
13
|
Forni Ogna V, Blanchard A, Vargas-Poussou R, Ogna A, Baron S, Bertocchio JP, Prot-Bertoye C, Nevoux J, Dubourg J, Maruani G, Mendes M, Garcia-Castaño A, Treard C, Lepottier N, Houillier P, Courbebaisse M. Signification of distal urinary acidification defects in hypocitraturic patients. PLoS One 2017; 12:e0177329. [PMID: 28542241 PMCID: PMC5438111 DOI: 10.1371/journal.pone.0177329] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 04/10/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Hypocitraturia has been associated with metabolic acidosis and mineral disorders. The aim of this study was to investigate the occurrence of urinary acidification defects underlying hypocitraturia. MATERIALS AND METHODS This retrospective observational study included 67 patients (32 men), aged 40.7±15.1 years with hypocitraturia (<1.67 mmol/24-h) and nephrolithiasis, nephrocalcinosis, and/or bone demineralization, referred to our center from 2000 to 2015. We aimed to assess renal distal acidification capacity, prevalence and mechanisms of urinary acidification defects. Patients with low baseline plasma HCO3- (<22 mmol/L) were studied by bicarbonate loading or furosemide/fludrocortisone tests. Patients with normal baseline plasma HCO3- had an ammonium-chloride challenge test. A normal response was a decrease in urinary pH <5.3 and an increase in urinary NH4+ ≥33 μmol/min and defined idiopathic hypocitraturia. RESULTS Eleven patients (16.4%) had low HCO3- and overt distal acidification defect. Three had a mutation in the gene encoding AE1, 4 had Gougerot-Sjögren syndrome and no cause was found in the remaining 4 cases. Fifty-six patients (83.6%) had normal HCO3-; of those, 33 (58.9%) had idiopathic hypocitraturia. Among the 23 (41%) remaining patients, 12 were unable to increase urinary NH4+ excretion (among them, 8 were able to decrease urinary pH and 4 were not) whereas 11 were able to increase urinary NH4+ excretion but unable to decrease urinary pH. These 11 patients had higher fasting urinary calcium, reflecting bone resorption, than the other 12 patients: median 0.41 [0.24-0.47] vs. 0.22 [0.08-0.37] mmol/mmol creatinine (P = 0.04). CONCLUSIONS Patients with hypocitraturia and normal plasma HCO3- frequently show a latent acidification defect that can be further dissected into one of several subtypes based on urinary pH and NH4+ response to the acid load. Those patients with impaired urine acidification capacity but preserved NH4+ excretion exhibit particularly high calciuria and should be identified to optimize nephrolithiasis prevention.
Collapse
Affiliation(s)
- Valentina Forni Ogna
- Centre d’Investigations Cliniques, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Anne Blanchard
- Centre d’Investigations Cliniques, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, Paris, France
- Centre de Référence des Maladies Rénales Héréditaires de l’Enfant et de l’Adulte (MARHEA), Paris, France
- Université Paris Descartes, Faculté de Médecine, Paris, France
| | - Rosa Vargas-Poussou
- Centre de Référence des Maladies Rénales Héréditaires de l’Enfant et de l’Adulte (MARHEA), Paris, France
- Service de Génétique, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Adam Ogna
- INSERM CIC 14.29, Hôpital Raymond Poincaré, Assistance Publique-Hôpitaux de Paris, Garches, France
| | - Stéphanie Baron
- Université Paris Descartes, Faculté de Médecine, Paris, France
- Département de Physiologie, Unité rénale, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Jean-Philippe Bertocchio
- Université Paris Descartes, Faculté de Médecine, Paris, France
- Département de Physiologie, Unité rénale, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Caroline Prot-Bertoye
- Université Paris Descartes, Faculté de Médecine, Paris, France
- Département de Physiologie, Unité rénale, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Jérôme Nevoux
- Service d’ORL, Hôpital Bicêtre, Assistance Publique-Hôpitaux de Paris, Paris, France
- Université Paris-Saclay, Paris, France
- INSERM 1182, Paris, France
| | - Julie Dubourg
- Centre d’Investigations Cliniques, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Gérard Maruani
- INSERM CIC 14.29, Hôpital Raymond Poincaré, Assistance Publique-Hôpitaux de Paris, Garches, France
- Institut Necker Enfants-Malades, INSERM U1151 –CNRS UMR 8253, Paris, France
| | - Margarida Mendes
- Centre d’Investigations Cliniques, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Alejandro Garcia-Castaño
- Service de Génétique, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Cyrielle Treard
- Service de Génétique, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Nelly Lepottier
- Service de Génétique, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Pascal Houillier
- Université Paris Descartes, Faculté de Médecine, Paris, France
- Département de Physiologie, Unité rénale, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, Paris, France
- INSERM UMR_S1138, CNRS ERL8228, Paris, France
| | - Marie Courbebaisse
- Université Paris Descartes, Faculté de Médecine, Paris, France
- Département de Physiologie, Unité rénale, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, Paris, France
- Institut Necker Enfants-Malades, INSERM U1151 –CNRS UMR 8253, Paris, France
- * E-mail:
| |
Collapse
|
14
|
Sromicki JJ, Hess B. Abnormal distal renal tubular acidification in patients with low bone mass: prevalence and impact of alkali treatment. Urolithiasis 2016; 45:263-269. [PMID: 27412028 DOI: 10.1007/s00240-016-0906-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 07/02/2016] [Indexed: 11/25/2022]
Abstract
Chronic acid retention is known to promote bone dissolution. In this study, 23 % of patients with osteopenia/osteoporosis were diagnosed with abnormal distal renal tubular acidification (dRTA), a kidney dysfunction leading to chronic acid retention. Treating those patients with alkali-therapy shows improvement in bone density. To evaluate the prevalence of abnormal distal renal tubular acidification in patients with low bone mass (LBM) and the impact of additional alkali treatment on bone density in patients with concomitant LBM and dRTA,183 patients referred for metabolic evaluation of densitometrically proven low bone mass were screened for abnormal distal renal tubular acidification between 2006 and 2013. In all LBM urine pH (U-pH) was measured in the 2nd morning urines after 12 h of fasting. If U-pH was ≥5.80, LBM underwent a 1-day ammonium chloride loading, and U-pH was remeasured the next morning. If U-pH after acid loading did not drop below 5.45, patients were diagnosed with abnormal distal renal tubular acidification. Normal values were obtained from 21 healthy controls. All LBM with dRTA were recommended alkali citrate in addition to conventional therapy of LBM, and follow-up DXAs were obtained until 2014. 85 LBM underwent NH4Cl loading. 42 LBM patients were diagnosed with incomplete dRTA (idRTA; prevalence 23.0 %). During follow-up (1.6-8 years) of idRTA-LBM patients, subjects adhering to alkali treatment tended to improve BMD at all sites measured, whereas BMD of non-adherent idRTA patients worsened/remained unchanged. (1) About one out of four patients with osteopenia/osteoporosis has idRTA. (2) Upon NH4Cl loading, idRTA patients do not lower urine pH normally, but show signs of increased acid-buffering by bone dissolution. (3) In idRTA patients with low bone mass on conventional therapy, additional long-term alkali treatment improves bone mass at lumbar spine and potentially at other bone sites. (4) All patients with low bone mass undergoing metabolic evaluation should be screened for idRTA.
Collapse
Affiliation(s)
- Jerzy Jan Sromicki
- Internal Medicine and Nephrology, Osteoporosis Center Zimmerberg, University of Zurich, Bellariastrasse 38, Klinik Im Park, 8038, Zurich, Switzerland
- Division of General Surgery, University Hospital, 8091, Zurich, Switzerland
| | - Bernhard Hess
- Internal Medicine and Nephrology, Osteoporosis Center Zimmerberg, University of Zurich, Bellariastrasse 38, Klinik Im Park, 8038, Zurich, Switzerland.
| |
Collapse
|
15
|
Both T, Zillikens MC, Hoorn EJ, Zietse R, van Laar JAM, Dalm VASH, van Duijn CM, Versnel MA, Maria NI, van Hagen PM, van Daele PLA. Bone Mineral Density in Sjögren Syndrome Patients with and Without Distal Renal Tubular Acidosis. Calcif Tissue Int 2016; 98:573-9. [PMID: 26873478 PMCID: PMC4860192 DOI: 10.1007/s00223-016-0112-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Accepted: 01/18/2016] [Indexed: 11/29/2022]
Abstract
Primary Sjögren's syndrome (pSS) can be complicated by distal renal tubular acidosis (dRTA), which may contribute to low bone mineral density (BMD). Our objective was to evaluate BMD in pSS patients with and without dRTA as compared with healthy controls. BMD of lumbar spine (LS) and femoral neck (FN) was measured in 54 pSS patients and 162 healthy age- and sex-matched controls by dual-energy X-ray absorptiometry (DXA). dRTA was defined as inability to reach urinary pH <5.3 after an ammonium chloride (NH4Cl) test. LS- and FN-BMD were significantly higher in pSS patients compared with controls (1.18 ± 0.21 g/cm(2) for patients vs. 1.10 ± 0.18 g/cm(2) for controls, P = 0.008 and 0.9 ± 0.16 g/cm(2) for patients vs. 0.85 ± 0.13 g/cm(2) for controls, P = 0.009, respectively). After adjustment for BMI and smoking, the LS- and FN-BMD remained significantly higher. Patients with dRTA (N = 15) did not have a significantly different LS- and FN-BMD compared with those without dRTA (N = 39) after adjustment for BMI, age, and gender. Thirty-seven (69 %) pSS patients were using hydroxychloroquine (HCQ). Unexpectedly, pSS patients had a significantly higher LS- and FN-BMD compared with healthy controls. Patients with dRTA had similar BMD compared with patients without dRTA. We postulate that an explanation for the higher BMD in pSS patients may be the frequent use of HCQ.
Collapse
Affiliation(s)
- Tim Both
- Division of Clinical Immunology, Department of Internal Medicine, PO Box 2040, Room D-419, 3000 CA, Rotterdam, The Netherlands.
| | - M Carola Zillikens
- Department of Endocrinology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Ewout J Hoorn
- Department of Nephrology & Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Robert Zietse
- Department of Nephrology & Transplantation, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Jan A M van Laar
- Division of Clinical Immunology, Department of Internal Medicine, PO Box 2040, Room D-419, 3000 CA, Rotterdam, The Netherlands
- Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Virgil A S H Dalm
- Division of Clinical Immunology, Department of Internal Medicine, PO Box 2040, Room D-419, 3000 CA, Rotterdam, The Netherlands
- Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | - Marjan A Versnel
- Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Naomi I Maria
- Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - P Martin van Hagen
- Division of Clinical Immunology, Department of Internal Medicine, PO Box 2040, Room D-419, 3000 CA, Rotterdam, The Netherlands
- Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Paul L A van Daele
- Division of Clinical Immunology, Department of Internal Medicine, PO Box 2040, Room D-419, 3000 CA, Rotterdam, The Netherlands
- Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| |
Collapse
|
16
|
Shavit L, Chen L, Ahmed F, Ferraro PM, Moochhala S, Walsh SB, Unwin R. Selective screening for distal renal tubular acidosis in recurrent kidney stone formers: initial experience and comparison of the simultaneous furosemide and fludrocortisone test with the short ammonium chloride test. Nephrol Dial Transplant 2016; 31:1870-1876. [PMID: 26961999 DOI: 10.1093/ndt/gfv423] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 11/10/2015] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Distal renal tubular acidosis (dRTA) is associated with renal stone disease, and it often needs to be considered and excluded in some recurrent calcium kidney stone formers (KSFs). However, a diagnosis of dRTA, especially when 'incomplete', can be missed and needs to be confirmed by a urinary acidification (UA) test. The gold standard reference test is still the short ammonium chloride (NH4Cl) test, but it is limited by gastrointestinal side effects and occasionally failure to ingest sufficient NH4Cl. For this reason, the furosemide plus fludrocortisone (F+F) test has been proposed as an easier and better-tolerated screening test. The aim of the present study was to assess the usefulness of the F+F test as a clinical screening tool for dRTA in a renal stone clinic. METHODS We studied 124 patients retrospectively in whom incomplete dRTA was suspected: 71 had kidney stones only, 9 had nephrocalcinosis only and 44 had both. A total of 158 UA tests were performed: 124 F+F and 34 NH4Cl; both tests were completed in 34 patients. RESULTS The mean age was 45.4 ± 15 years, and 49% of patients were male. The prevalence of complete and incomplete dRTAs was 7 and 13.7%, respectively. Of the 34 patients tested using both tests, 17 (50%) were abnormal and 4 (12%) were normal. Thirteen (39%) patients were abnormal by F+F, but normal by NH4Cl [sensitivity 100% (95% CI 80-100), specificity 24% (95% CI 7-50), positive predictive value 57% (95% CI 37-75), negative predictive value 100% (95% CI 40-100)]. CONCLUSIONS The F+F test is characterized by an excellent sensitivity and negative predictive value, and the diagnosis of incomplete dRTA can be excluded reliably in a patient who acidifies their urine normally with this test. However, its lack of specificity is a drawback, and if there is any doubt, an abnormal F+F test may need to be confirmed by a follow-up NH4Cl test. Ideally, a prospective blinded study in unselected KSFs is needed to accurately assess the reliability of the F+F test in diagnosing, rather than excluding, dRTA.
Collapse
Affiliation(s)
- Linda Shavit
- UCL Centre for Nephrology, University College London Medical School, Royal Free Campus and Hospital, London, UK
- Adult Nephrology Unit, Shaare Zedek Medical Center, Jerusalem, Israel
| | - Lucia Chen
- UCL Centre for Nephrology, University College London Medical School, Royal Free Campus and Hospital, London, UK
| | - Fayha Ahmed
- Department of Clinical Biochemistry, Royal Free Hospital, London, UK
| | | | - Shabbir Moochhala
- UCL Centre for Nephrology, University College London Medical School, Royal Free Campus and Hospital, London, UK
| | - Steven B Walsh
- UCL Centre for Nephrology, University College London Medical School, Royal Free Campus and Hospital, London, UK
| | - Robert Unwin
- UCL Centre for Nephrology, University College London Medical School, Royal Free Campus and Hospital, London, UK
| |
Collapse
|
17
|
Dhayat NA, Schaller A, Albano G, Poindexter J, Griffith C, Pasch A, Gallati S, Vogt B, Moe OW, Fuster DG. The Vacuolar H+-ATPase B1 Subunit Polymorphism p.E161K Associates with Impaired Urinary Acidification in Recurrent Stone Formers. J Am Soc Nephrol 2015; 27:1544-54. [PMID: 26453614 DOI: 10.1681/asn.2015040367] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 09/02/2015] [Indexed: 11/03/2022] Open
Abstract
Mutations in the vacuolar-type H(+)-ATPase B1 subunit gene ATP6V1B1 cause autosomal-recessive distal renal tubular acidosis (dRTA). We previously identified a single-nucleotide polymorphism (SNP) in the human B1 subunit (c.481G>A; p.E161K) that causes greatly diminished pump function in vitro To investigate the effect of this SNP on urinary acidification, we conducted a genotype-phenotype analysis of recurrent stone formers in the Dallas and Bern kidney stone registries. Of 555 patients examined, 32 (5.8%) were heterozygous for the p.E161K SNP, and the remaining 523 (94.2%) carried two wild-type alleles. After adjustment for sex, age, body mass index, and dietary acid and alkali intake, p.E161K SNP carriers had a nonsignificant tendency to higher urinary pH on a random diet (6.31 versus 6.09; P=0.09). Under an instructed low-Ca and low-Na diet, urinary pH was higher in p.E161K SNP carriers (6.56 versus 6.01; P<0.01). Kidney stones of p.E161K carriers were more likely to contain calcium phosphate than stones of wild-type patients. In acute NH4Cl loading, p.E161K carriers displayed a higher trough urinary pH (5.34 versus 4.89; P=0.01) than wild-type patients. Overall, 14.6% of wild-type patients and 52.4% of p.E161K carriers were unable to acidify their urine below pH 5.3 and thus, can be considered to have incomplete dRTA. In summary, our data indicate that recurrent stone formers with the vacuolar H(+)-ATPase B1 subunit p.E161K SNP exhibit a urinary acidification deficit with an increased prevalence of calcium phosphate-containing kidney stones. The burden of E161K heterozygosity may be a forme fruste of dRTA.
Collapse
Affiliation(s)
- Nasser A Dhayat
- Swiss National Centres of Competence in Research Kidney.CH and TransCure and Divisions of Nephrology, Hypertension and Clinical Pharmacology, Clinical Research, Bern University Hospital, University of Bern, Switzerland; and
| | - Andre Schaller
- Clinical Research, Bern University Hospital, University of Bern, Switzerland; and Human Genetics, and Departments of Pediatrics and
| | - Giuseppe Albano
- Swiss National Centres of Competence in Research Kidney.CH and TransCure and Divisions of Nephrology, Hypertension and Clinical Pharmacology, Clinical Research, Bern University Hospital, University of Bern, Switzerland; and Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - John Poindexter
- Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, and
| | - Carolyn Griffith
- Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, and
| | - Andreas Pasch
- Swiss National Centres of Competence in Research Kidney.CH and TransCure and Divisions of Nephrology, Hypertension and Clinical Pharmacology, Clinical Research, Bern University Hospital, University of Bern, Switzerland; and
| | - Sabina Gallati
- Clinical Research, Bern University Hospital, University of Bern, Switzerland; and Human Genetics, and Departments of Pediatrics and
| | - Bruno Vogt
- Swiss National Centres of Competence in Research Kidney.CH and TransCure and Divisions of Nephrology, Hypertension and Clinical Pharmacology, Clinical Research, Bern University Hospital, University of Bern, Switzerland; and
| | - Orson W Moe
- Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, and Departments of Internal Medicine and Physiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Daniel G Fuster
- Swiss National Centres of Competence in Research Kidney.CH and TransCure and Divisions of Nephrology, Hypertension and Clinical Pharmacology, Clinical Research, Bern University Hospital, University of Bern, Switzerland; and Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland;
| |
Collapse
|
18
|
Calcium nephrolithiasis and bone demineralization: pathophysiology, diagnosis, and medical management. Curr Opin Urol 2015; 24:633-8. [PMID: 25188231 DOI: 10.1097/mou.0000000000000111] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE OF REVIEW To establish the relationship between calcium nephrolithiasis, bone densitometry scoring, and bone mineral density (BMD) loss according to bone turnover markers (BTMs) and urinary metabolites. RECENT FINDINGS Patients with recurrent calcium nephrolithiasis and idiopathic fasting hypercalciuria (urinary calcium/creatinine ratio >0.11) are more likely to have BMD loss that may lead to osteopenia or osteoporosis. In these patients, BTMs may be used as a surrogate for both bone health and stone recurrence. Suspect higher lithogenic states when calcium stone formers have serum beta-crosslaps (resorptive marker) greater than 0.311 ng/ml, serum osteocalcin (formative marker) greater than 13.2 ng/ml, and beta-crosslaps/osteocalcin ratio greater than 0.024. SUMMARY Patients with recurrent calcium nephrolithiasis and fasting hypercalciuria have a higher incidence of osteopenia and osteoporosis, measured by the dual-energy X-ray absorptiometry. These patients present not only with hypercalciuria and increased BTMs (mainly resorptive), but also up to 30% have hypocitraturia and increased urinary calcium/citrate ratio (>0.25). On the basis of these results, a diagnostic algorithm was created, classifying hypercalciurics according to their fasting calcium/creatinine and calcium/citrate ratio. Medical therapy for these patients is aimed at improving the dietary habits (normocalcemic, low salt, low animal protein diet), prescribing combinations of potassium citrate, thiazides, and bisphosphonates, and correcting bone and urinary abnormalities that may lower future skeletal and kidney stone risk.
Collapse
|
19
|
Both T, Hoorn EJ, Zietse R, van Laar JAM, Dalm VASH, Brkic Z, Versnel MA, van Hagen PM, van Daele PLA. Prevalence of distal renal tubular acidosis in primary Sjögren's syndrome. Rheumatology (Oxford) 2014; 54:933-9. [PMID: 25354755 DOI: 10.1093/rheumatology/keu401] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES Our objectives were to analyse the prevalence of distal renal tubular acidosis (dRTA) in primary SS (pSS) and to compare a novel urinary acidification test with furosemide and fludrocortisone (FF) with the gold standard ammonium chloride (NH4Cl) to detect dRTA. METHODS Urinary acidification was assessed in 57 pSS patients using NH4Cl and FF. A urinary acidification defect was defined as an inability to reach a urinary pH of <5.3 after NH4Cl. RESULTS The prevalence of complete dRTA (urinary acidification defect with acidosis) was 5% (3/57). All three patients had positive SSA/Ro and SSB/La autoantibodies and impaired kidney function. The prevalence of incomplete dRTA (urinary acidification defect without acidosis) was 25% (14/57). Compared with patients without dRTA, patients with incomplete dRTA had significantly lower venous pH and serum bicarbonate and higher urinary pH. SSB/La antibodies were more prevalent in the dRTA groups (P < 0.05). Compared with NH4Cl, the positive and negative predictive values of FF were 46% and 82%, respectively. Vomiting occurred more often during the urinary acidification test with NH4Cl than with FF (9 vs 0, P < 0.05). CONCLUSION Incomplete dRTA is common in pSS and causes mild acidaemia and higher urinary pH, which may contribute to bone demineralization and kidney stone formation. FF cannot replace NH4Cl in testing urinary acidification in pSS, but may be considered as a screening tool, given its reasonable negative predictive value and better tolerability.
Collapse
Affiliation(s)
- Tim Both
- Division of Clinical Immunology and Division of Nephrology and Transplantation, Department of Internal Medicine and Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Ewout J Hoorn
- Division of Clinical Immunology and Division of Nephrology and Transplantation, Department of Internal Medicine and Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Robert Zietse
- Division of Clinical Immunology and Division of Nephrology and Transplantation, Department of Internal Medicine and Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Jan A M van Laar
- Division of Clinical Immunology and Division of Nephrology and Transplantation, Department of Internal Medicine and Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands Division of Clinical Immunology and Division of Nephrology and Transplantation, Department of Internal Medicine and Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Virgil A S H Dalm
- Division of Clinical Immunology and Division of Nephrology and Transplantation, Department of Internal Medicine and Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands Division of Clinical Immunology and Division of Nephrology and Transplantation, Department of Internal Medicine and Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Zana Brkic
- Division of Clinical Immunology and Division of Nephrology and Transplantation, Department of Internal Medicine and Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Marjan A Versnel
- Division of Clinical Immunology and Division of Nephrology and Transplantation, Department of Internal Medicine and Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - P Martin van Hagen
- Division of Clinical Immunology and Division of Nephrology and Transplantation, Department of Internal Medicine and Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands Division of Clinical Immunology and Division of Nephrology and Transplantation, Department of Internal Medicine and Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Paul L A van Daele
- Division of Clinical Immunology and Division of Nephrology and Transplantation, Department of Internal Medicine and Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands Division of Clinical Immunology and Division of Nephrology and Transplantation, Department of Internal Medicine and Department of Immunology, Erasmus Medical Center, Rotterdam, The Netherlands
| |
Collapse
|
20
|
Zhang J, Fuster DG, Cameron MA, Quiñones H, Griffith C, Xie XS, Moe OW. Incomplete distal renal tubular acidosis from a heterozygous mutation of the V-ATPase B1 subunit. Am J Physiol Renal Physiol 2014; 307:F1063-71. [PMID: 25164082 DOI: 10.1152/ajprenal.00408.2014] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Congenital distal renal tubular acidosis (RTA) from mutations of the B1 subunit of V-ATPase is considered an autosomal recessive disease. We analyzed a distal RTA kindred with a truncation mutation of B1 (p.Phe468fsX487) previously shown to have failure of assembly into the V1 domain of V-ATPase. All heterozygous carriers in this kindred have normal plasma HCO3- concentrations and thus evaded the diagnosis of RTA. However, inappropriately high urine pH, hypocitraturia, and hypercalciuria were present either individually or in combination in the heterozygotes at baseline. Two of the heterozygotes studied also had inappropriate urinary acidification with acute ammonium chloride loading and an impaired urine-blood Pco2 gradient during bicarbonaturia, indicating the presence of a H+ gradient and flux defects. In normal human renal papillae, wild-type B1 is located primarily on the plasma membrane, but papilla from one of the heterozygote who had kidney stones but not nephrocalcinosis showed B1 in both the plasma membrane as well as diffuse intracellular staining. Titration of increasing amounts of the mutant B1 subunit did not exhibit negative dominance over the expression, cellular distribution, or H+ pump activity of wild-type B1 in mammalian human embryonic kidney-293 cells and in V-ATPase-deficient Saccharomyces cerevisiae. This is the first demonstration of renal acidification defects and nephrolithiasis in heterozygous carriers of a mutant B1 subunit that cannot be attributable to negative dominance. We propose that heterozygosity may lead to mild real acidification defects due to haploinsufficiency. B1 heterozygosity should be considered in patients with calcium nephrolithiasis and urinary abnormalities such as alkalinuria or hypocitraturia.
Collapse
Affiliation(s)
- Jianning Zhang
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Daniel G Fuster
- Department of Nephrology and Hypertension and Institute of Biochemistry and Molecular Medicine, Inselspital, University of Bern, Bern, Switzerland
| | - Mary Ann Cameron
- Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Henry Quiñones
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Carolyn Griffith
- Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Xiao-Song Xie
- McDermott Center of Human Development, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Orson W Moe
- Charles and Jane Pak Center of Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas;
| |
Collapse
|
21
|
Everything you need to know about distal renal tubular acidosis in autoimmune disease. Rheumatol Int 2014; 34:1037-45. [PMID: 24682397 PMCID: PMC4107275 DOI: 10.1007/s00296-014-2993-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 03/14/2014] [Indexed: 11/24/2022]
Abstract
Renal acid–base homeostasis is a complex process, effectuated by bicarbonate reabsorption and acid secretion. Impairment of urinary acidification is called renal tubular acidosis (RTA). Distal renal tubular acidosis (dRTA) is the most common form of the RTA syndromes. Multiple pathophysiologic mechanisms, each associated with various etiologies, can lead to dRTA. The most important consequence of dRTA is (recurrent) nephrolithiasis. The diagnosis is based on a urinary acidification test. Potassium citrate is the treatment of choice.
Collapse
|
22
|
Siener R, Netzer L, Hesse A. Determinants of brushite stone formation: a case-control study. PLoS One 2013; 8:e78996. [PMID: 24265740 PMCID: PMC3827110 DOI: 10.1371/journal.pone.0078996] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 09/25/2013] [Indexed: 11/25/2022] Open
Abstract
Purpose The occurrence of brushite stones has increased during recent years. However, the pathogenic factors driving the development of brushite stones remain unclear. Methods Twenty-eight brushite stone formers and 28 age-, sex- and BMI-matched healthy individuals were enrolled in this case-control study. Anthropometric, clinical, 24 h urinary parameters and dietary intake from 7-day weighed food records were assessed. Results Pure brushite stones were present in 46% of patients, while calcium oxalate was the major secondary stone component. Urinary pH and oxalate excretion were significantly higher, whereas urinary citrate was lower in patients as compared to healthy controls. Despite lower dietary intake, urinary calcium excretion was significantly higher in brushite stone patients. Binary logistic regression analysis revealed pH>6.50 (OR 7.296; p = 0.035), calcium>6.40 mmol/24 h (OR 25.213; p = 0.001) and citrate excretion <2.600 mmol/24 h (OR 15.352; p = 0.005) as urinary risk factors for brushite stone formation. A total of 56% of patients exhibited distal renal tubular acidosis (dRTA). Urinary pH, calcium and citrate excretion did not significantly differ between patients with or without dRTA. Conclusions Hypercalciuria, a diminished citrate excretion and an elevated pH turned out to be the major urinary determinants of brushite stone formation. Interestingly, urinary phosphate was not associated with urolithiasis. The increased urinary oxalate excretion, possibly due to decreased calcium intake, promotes the risk of mixed stone formation with calcium oxalate. Neither dietary factors nor dRTA can account as cause for hypercalciuria, higher urinary pH and diminished citrate excretion. Further research is needed to define the role of dRTA in brushite stone formation and to evaluate the hypothesis of an acquired acidification defect.
Collapse
Affiliation(s)
- Roswitha Siener
- University Stone Centre, Department of Urology, University of Bonn, Bonn, Germany
- * E-mail:
| | - Linda Netzer
- University Stone Centre, Department of Urology, University of Bonn, Bonn, Germany
| | - Albrecht Hesse
- University Stone Centre, Department of Urology, University of Bonn, Bonn, Germany
| |
Collapse
|
23
|
Tekçe H, Aktaş G, Öztürk S. A distal (type 1) renal tubular acidosis case that mimic coronary ischemia. Ren Fail 2013; 35:1289-91. [PMID: 23906332 DOI: 10.3109/0886022x.2013.820662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
24
|
Abstract
Kidney stones composed predominantly (50% or more) of calcium phosphate constitute up to 10% of all stones and 15%-20% of calcium stones, 80% of which are composed of calcium oxalate. Calcium phosphate is a minor component of up to 30% of calcium oxalate stones as well. The cause of calcium phosphate stones is often obscure but most often related to a high urine pH. Some patients with calcium phosphate stones may have incomplete renal tubular acidosis. Others have distal renal tubular acidosis characterized by hyperchloremic acidosis, hypocitraturia, and high urine pH. The use of carbonic anhydrase inhibitors such as acetazolamide, topiramate, and zonisamide leads to a similar picture. Treatment options to specifically prevent calcium phosphate stone recurrence have not been tested in clinical trials. Increases in urine volume and restriction of sodium intake to limit calcium excretion are important. Citrate supplementation is probably effective, although the concomitant increase in urine pH may increase calcium phosphate supersaturation and partially offset the inhibition of crystallization resulting from the increased urine citrate excretion and the alkali-associated reduction in urine calcium excretion. Thiazides lower urine calcium excretion and may help ensure the safety of citrate supplementation.
Collapse
Affiliation(s)
- David S Goldfarb
- Nephrology Section, New York Harbor Department of Veterans Affairs Healthcare System, New York, NY 10010, USA.
| |
Collapse
|
25
|
Metaphylaxis, diet and lifestyle in stone disease. Arab J Urol 2012; 10:240-9. [PMID: 26558032 PMCID: PMC4442949 DOI: 10.1016/j.aju.2012.03.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 03/16/2012] [Accepted: 03/19/2012] [Indexed: 02/06/2023] Open
Abstract
Objective The most common urinary stones (calcium salts, uric acid) form due to genetic factors and lifestyle. This review describes why, if and how medication and lifestyle changes can reduce the risk of formation. Methods Previous reports were reviewed to obtain information on three aspects of urolithiasis, i.e. epidemiology, mechanisms linking lifestyle and urolithiasis and lifestyle intervention for preventing urolithiasis. Results Epidemiological evidence links the prevalence of urinary stone formation to general lifestyle factors. Detailed analysis has identified individual lifestyle elements that affect the risk of urinary stone formation. Currently there are several concepts that explain the mechanism of stone formation. Urinary markers like calcium, oxalate, phosphate, uric acid and urinary pH are involved in all these concepts. Many studies show that changing (combinations of) specific lifestyle elements has a favourable effect on these urinary markers. Based on this evidence, protocols have been developed that use a combination of these lifestyle changes and medication to prevent stone formation. In well-controlled studies where patients are optimally informed and continuously motivated, these protocols clearly reduce the stone formation rate. In general practice the result is less clear, because the time and tools are insufficient to maintain long-term patient compliance in the use of medication and lifestyle advice. Conclusion The risk of stone formation can be reduced in general practice when the patient’s compliance is optimised by providing individualised advice, continuous information, and feedback and incorporation of the advice into a regular lifestyle. The use of ‘e-tools’ might enable this without increasing the time required from the physician.
Collapse
|
26
|
Choi JS, Kim CS, Park JW, Bae EH, Ma SK, Kim SW. Incomplete distal renal tubular acidosis with nephrocalcinosis. Chonnam Med J 2012; 47:170-2. [PMID: 22247918 PMCID: PMC3252506 DOI: 10.4068/cmj.2011.47.3.170] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 11/28/2011] [Indexed: 11/23/2022] Open
Abstract
We report the case of a female patient with incomplete distal renal tubular acidosis with nephrocalcinosis. She was admitted to the hospital because of acute pyelonephritis. Imaging studies showed dual medullary nephrocalcinosis. Subsequent evaluations revealed hypokalemia, hypocalcemia, hypercalciuria, and hypocitraturia with normal acid-base status. A modified tubular acidification test with NH4Cl confirmed a defect of urine acidification, which is compatible with incomplete distal tubular acidosis. We treated our patient with potassium citrate, which corrects hypokalemia and prevents further deposition of calcium salts.
Collapse
Affiliation(s)
- Joon Seok Choi
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
| | | | | | | | | | | |
Collapse
|