Drug-Induced Renal Calculi

Spectral characterization of renal calculi collected from population in downtown Madrid (Spain)

This paper reports on a comprehensive approach to characterize a set of kidney stones through various analytical techniques including ESEM-EDS, XRD, Raman, and CL spectroscopy, linked to an assessment of the patient's lifestyle and dietary habits. The use of these techniques can provide valuable insights into the underlying causes of stone formation and guide strategies for prevention and treatment. ESEM-EDS and XRD are commonly used techniques for kidney stone characterization due to their complementary nature, enabling the identification of a wide range of renal calculi. However, these techniques may not be sensitive enough to determine the detailed composition of the samples. In such cases, Raman and CL techniques can be used to provide more precise information about the chemical and structural composition of the stones. Raman spectroscopy, for example, can identify molecular phases observed under an optical microscope characterizing chemical compositions through vibrational modes associated with specific bonds. The CL spectral emission within the 250-850 nm range can also yield valuable information about the mineral phases, including the identification of structural crystallinity, hydrated molecules, Ca-OH bonds, and oxygen defects. By correlating spectral analyses with patient habits, this study identifies potential exogenous factors contributing to stone formation, including excess protein consumption, urinary bacterial infections, and oxalate-rich diets. This comprehensive approach provides a more complete understanding of the composition of kidney stones helping to personalized prevention and treatment strategies.

Uroliths composed of antiviral compound GS-441524 in 2 cats undergoing treatment for feline infectious peritonitis

Feline infectious peritonitis (FIP) historically has been a fatal disease in cats. Recent unlicensed use of antiviral medication has been shown to markedly improve survival of this infection. An 8-month-old female spayed domestic short-haired cat undergoing treatment for presumptive FIP with the antiviral nucleoside analog GS-441524 developed acute progressive azotemia. Abdominal ultrasound examination identified multifocal urolithiasis including renal, ureteral, and cystic calculi. Unilateral ureteral obstruction progressed to suspected bilateral ureteral obstruction and subcutaneous ureteral bypass (SUB) was performed along with urolith removal and submission for analysis. A 2-year-old male neutered domestic medium-haired cat undergoing treatment for confirmed FIP with GS-441524 developed dysuria (weak urine stream, urinary incontinence, and difficulty expressing the urinary bladder). This cat also was diagnosed sonographically with multifocal urolithiasis requiring temporary tube cystostomy after cystotomy and urolith removal. In both cases, initial urolith analysis showed unidentified material. Additional testing confirmed the calculi in both cats to be 98% consistent with GS-441524. Additional clinical studies are required to determine best screening practices for cats presented for urolithiasis during treatment with GS-441524.

Hydration for Adult Patients with Nephrolithiasis: Specificities and Current Recommendations

Nephrolithiasis affects around 10% of the population and is frequently associated with impaired dietary factors. The first one is insufficient fluid intake inducing reduced urine volume, urine supersaturation, and subsequently urinary lithiasis. Kidneys regulate 24 h urine volume, which, under physiological conditions, approximately reflects daily fluid intake. The aim of this study is to synthesize and highlight the role of hydration in the treatment of nephrolithiasis. Increasing fluid intake has a preventive effect on the risk of developing a first kidney stone (primary prevention) and also decreases the risk of stone recurrence (secondary prevention). Current guidelines recommend increasing fluid intake to at least at 2.5 L/day to prevent stone formation, and even to 3.5-4 L in some severe forms of nephrolithiasis (primary or enteric hyperoxaluria or cystinuria). Fluid intake must also be balanced between day and night, to avoid urinary supersaturation during the night. Patients should be informed and supported in this difficult process of increasing urine dilution, with practical ways and daily routines to increase their fluid intake. The liquid of choice is water, which should be chosen depending on its composition (such as calcium, bicarbonate, or magnesium content). Finally, some additional advice has to be given to avoid certain beverages such as those containing fructose or phosphoric acid, which are susceptible to increase the risk of nephrolithiasis.

Causal effects of inflammatory bowel diseases on the risk of kidney stone disease: a two-sample bidirectional mendelian randomization

BACKGROUND

Existing epidemiological observational studies have suggested interesting but inconsistent clinical correlations between inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), and kidney stone disease (KSD). Herein, we implemented a two-sample bidirectional Mendelian randomization (MR) to investigate the causal relationship between IBD and KSD.

METHODS

Data on IBD and KSD were obtained from Genome-Wide Association Studies (GWAS) summary statistics and the FinnGen consortium, respectively. Strict selection steps were used to screen for eligible instrumental SNPs. We applied inverse variance weighting (IVW) with the fix-effects model as the major method. Several sensitivity analyses were used to evaluate pleiotropy and heterogeneity. Causal relationships between IBD and KSD were explored in two opposite directions. Furthermore, we carried out multivariable MR (MVMR) to obtain the direct causal effects of IBD on KSD.

RESULTS

Our results demonstrated that CD could increase the risk of KSD (IVW: OR = 1.06, 95% CI = 1.03-1.10, p < 0.001). Similar results were found in the validation group (IVW: OR = 1.05, 95% CI = 1.01-1.08, p = 0.013) and in the MVMR analysis. Meanwhile, no evidence of a causal association between UC and KSD was identified. The reverse MR analysis detected no causal association.

CONCLUSIONS

This MR study verified that CD plays a critical role in developing kidney stones and that the effect of UC on KSD needs to be further explored.

Lower Urinary Tract Disorders as Adverse Drug Reactions-A Literature Review

A potential complication of pharmacotherapy for a given patient is the possibility of various side effects of drugs, which are manifested in many ways and constitute iatrogenic causes of diseases. Among the systemic side effects of drugs, there are also those involving the urinary tract, although these are less reported in the literature. The use of numerous drugs-especially of anticholinergics or drugs with anticholinergic potential, opioid analgesics, non-steroidal anti-inflammatory drugs, antidepressants, first-generation antipsychotics (classic neuroleptics) and selected cardiovascular drugs (beta-blockers, thiazides potassium-sparing diuretics, statins), as well as others-may increase the risk of developing urological disorders, such as urinary retention or incontinence, urinary tract infections, urolithiasis, erectile dysfunction in men and retroperitoneal fibrosis. The purpose of this paper is to characterise the abovementioned drug-induced disorders of the lower urinary tract on the basis of a non-systematic literature review.

The effectiveness of citrates and pyridoxine in the treatment of kidney stones

The prevalence of nephrolithiasis is increasing across all demographic groups. Apart from the morbidity associated with an acute occurrence, preventative treatment is essential for stone disease, which can become a long-term problem. Simple interventions like fluid intake optimization and dietary modification are effective for most stone types. However, patients with specific metabolic abnormalities may require pharmaceutical therapy if lifestyle changes are insufficient to reduce the risk of stone recurrence. The treatment of citrates and/or pyridoxines may help eliminate or prevent recurrences of kidney stones, especially when they are composed of uric acid, calcium oxalate, calcium phosphate, or the latter two together. In cases of struvite stones, which often necessitate a surgical approach, acetohydroxamic acid emerges as a valuable second-line treatment option. Thiol-binding agents may be needed for cystinuria, as well as lifestyle modifications. Successful treatment reduces stone recurrence and the need to remove stones surgically.

Ceftriaxone Administration Associated with Lithiasis in Children: Guilty or Not? A Systematic Review

Lithiasis is a known side effect of ceftriaxone administration in children. Sex, age, weight, dosage, and duration of intake have been reported as risk factors for the formation of calcification or stones in the bile and urine excretory systems of children who received ceftriaxone. The purpose of this systematic review is to investigate the reported effects of ceftriaxone administration in pediatric patients who were admitted to a hospital due to infection, the likelihood of gallstones, nephroliths, or precipitations in both the biliary and urinary systems, as well as investigate the relationship with their mother's history during pregnancy. Original studies and literature reviews from the PubMed database were included in the study. No time limit related to research or publication was set for the articles. The results were evaluated, aiming to understand the outcomes and identify any predisposing factors relevant to this side effect. Of the 181 found articles, 33 were appropriate for inclusion in the systematic review. The administered dose of ceftriaxone presented variability. Symptoms, such as abdominal pain and vomiting, were associated with ceftriaxone-related lithiasis in many cases. It was noted that most of the results were the outcomes of retrospective observation and not of prospective randomized research. Definitively, more randomized control studies with long-term outcomes are needed to identify the exact association between ceftriaxone and lithiasis in children.

Acute Kidney Injury From Biopsy-Proven Renal Oxalosis From Excessive Intake of Vitamin C Leading to End-Stage Kidney Disease

We are presenting a case of a 55-year-old Caucasian female who presented with acute kidney injury requiring hemodialysis. Her native kidney biopsy showed extensive crystals in both the cortex and medulla, morphologically consistent with calcium oxalate crystals. The etiology was attributed to vitamin C-induced kidney hyperoxaluria. She has remained hemodialysis dependent for more than three months since the initial presentation, establishing a diagnosis of end-stage kidney disease.

The effect of Vitamin C and Zn supplementation on the immune system and clinical outcomes in COVID-19 patients

SARS-CoV-2 (Severe Acute Respiratory Syndrome-Coronavirus-2) is the most dangerous form of the coronavirus, which causes COVID-19. In patients with severe COVID-19, the immune system becomes markedly overactive. There is evidence that supplementation with select micronutrients may play a role in maintaining immune system function in this patient population. Throughout the COVID-19 pandemic, significant emphasis has been placed on the importance of supplementing critical micronutrients such as Vitamin C and Zinc (Zn) due to their immunomodulatory effects. Viral infections, like COVID-19, increase physiological demand for these micronutrients. Therefore, the purpose of this review was to provide comprehensive information regarding the potential effectiveness of Vitamin C and Zn supplementation during viral infection and specifically COVID-19. This review demonstrated a relation between Vitamin C and Zn deficiency and a reduction in the innate immune response, which can ultimately make patients with COVID-19 more vulnerable to viral infection. As such, adequate intake of Vitamin C and Zn, as an adjunctive therapeutic approach with any necessary pharmacological treatment(s), may be necessary to mitigate the adverse physiological effects of COVID-19. To truly clarify the role of Vitamin C and Zn supplementation in the management of COVID-19, we must wait for the results of ongoing randomized controlled trials. The toxicity of Vitamin C and Zn should also be considered to prevent over-supplementation. Over-supplementation of Vitamin C can lead to oxalate toxicity, while increased Zn intake can reduce immune system function. In summary, Vitamin C and Zn supplementation may be useful in mitigating COVID-19 symptomology.

How Do Drugs Affect the Skeleton? Implications for Forensic Anthropology

Simple Summary

Forensic anthropologists analyze human remains to assist in the identification of the deceased, predominantly by assessing age-at-death, sex, stature, ancestry and any unique identifying features. Whilst methods have been established to create this biological profile of the skeleton, these may be influenced by a number of factors. This paper, for the first time, provides an overview from a reading of the clinical and pharmacological literature to explore whether the intake of drugs can affect the skeleton and whether these may have implications for forensic anthropology casework. In effect, drugs such as tobacco, heroin, and prescription medications can alter bone mineral density, can increase the risk of fractures, destroy bone and changes to the dentition. By considering how drugs can affect the skeleton, forensic anthropologists can be aware of this when attempting to identify the deceased.

Abstract

Forensic anthropologists rely on a number of parameters when analyzing human skeletal remains to assist in the identification of the deceased, predominantly age-at-death, sex, stature, ancestry or population affinity, and any unique identifying features. During the examination of human remains, it is important to be aware that the skeletal features considered when applying anthropological methods may be influenced and modified by a number of factors, and particular to this article, prescription drugs (including medical and non-medical use) and other commonly used drugs. In view of this, this paper aims to review the medical, clinical and pharmacological literature to enable an assessment of those drug groups that as side effects have the potential to have an adverse effect on the skeleton, and explore whether or not they can influence the estimation of age-at-death, sex and other indicators of the biological profile. Moreover, it may be that the observation of certain alterations or inconsistencies in the skeleton may relate to the use of drugs or medication, and this in turn may help narrow down the list of missing persons to which a set of human remains could belong. The information gathered from the clinical and medical literature has been extracted with a forensic anthropological perspective and provides an awareness on how several drugs, such as opioids, cocaine, corticosteroids, non-steroidal anti-inflammatory drugs, alcohol, tobacco and others have notable effects on bone. Through different mechanisms, drugs can alter bone mineral density, causing osteopenia, osteoporosis, increase the risk of fractures, osteonecrosis, and oral changes. Not much has been written on the influence of drugs on the skeleton from the forensic anthropological practitioner perspective; and this review, in spite of its limitations and the requirement of further research, aims to investigate the current knowledge of the possible effects of both prescription and recreational drugs on bones, contributing to providing a better awareness in forensic anthropological practice and assisting in the identification process of the deceased.

OUP accepted manuscript

We report a rare case of urolithiasis induced by cefazolin sodium pentahydrate and review the relevant literature. A 12-year-old girl with right kidney injury was admitted to our hospital, a computed tomography scan revealed that no signs of disease in her left kidney but her right kidney was traumatized severely. After receiving cefazolin sodium pentahydrate, 2.0 g by intravenous infusion daily for 10 days, urolithiasis was found in the left urinary tract by computed tomography scan. Later, the patient complained of left back pain, nausea and vomiting, and a further computed tomography scan showed calculi persisted in the left urinary tract, and some of which had caused left hydronephrosis. A double-J catheter was placed in the left ureter, but no calculi were seen to drain with urine in the next 2 weeks, those calculi were removed by a flexible ureteroscope.

Correlation between Ion Composition of Oligomineral Water and Calcium Oxalate Crystal Formation

The ion content of drinking water might be associated with urinary stone formation, representing a keystone of conservative nephrolithiasis management. However, the effects of specific ions on calcium oxalate crystal formation and their mechanism of action are still highly controversial. We report an investigation of the effects of oligomineral waters with similar total salt amount but different ion composition on calcium oxalate (CaOx) precipitation in vitro, combining gravimetric and microscopic assays. The results suggest that the “collective” physicochemical properties of the aqueous medium, deriving from the ion combination rather than from a single ionic species, are of importance. Particularly, the ability of ions to strengthen/weaken the aqueous medium structure determines an increase/decrease in the interfacial energy, modulating the formation and growth of CaOx crystals.

Risk of Urolithiasis in Patients With Inflammatory Bowel Disease: A Nationwide Danish Cohort Study 1977-2018

BACKGROUND AND AIMS

Patients with inflammatory bowel disease (IBD) are suggested to be at increased risk of urolithiasis, but the magnitude of risk and the impact of medical and surgical treatment on this risk remain unknown. We therefore aimed to determine overall and treatment-related risk of urolithiasis in patients with IBD in a nationwide population-based cohort study.

METHODS

Using national registers, we identified all patients with IBD and all cases of urolithiasis in Denmark during 1977-2018. We obtained information on all IBD medications and surgical procedures during 1995-2018. IBD cases were matched 1:10 on age and sex to non-IBD individuals.

RESULTS

In total, 2,549 (3%) of 75,236 IBD patients and 11,258 (2%) of 767,403 non-IBD individuals developed urolithiasis, resulting in a 2-fold increased risk of urolithiasis (HR, 2.27; 95% CI, 2.17-2.38) in patients with IBD. The patients were also at increased risk of repetitive urolithiasis events (RR, 1.09; 95% CI: 1.04-1.15) and had increased risk of urolithiasis prior to IBD diagnosis (OR, 1.42; 95% CI: 1.34-1.50). After IBD diagnosis, risk of urolithiasis was associated with anti-TNF therapy and surgery.

CONCLUSION

Patients with IBD had a 2-fold increased risk of urolithiasis after IBD diagnosis and a 42% increased risk prior to IBD diagnosis. Risk was increased in anti-TNF exposed patients, and after surgery, suggesting that IBD severity per se and surgery, with altered intestinal absorption, increase risk of urolithiasis. Since stone formation is associated with adverse outcomes including sepsis, subpopulations of IBD patients, especially those undergoing strong immunosuppression might benefit from additional urolithiasis screening.

100% N4-acetyl-sulfamethoxazole stone induced by Trimethoprim-Sulfamethoxazole in an HIV patient being treated for toxoplasmosis

Trimethoprim-Sulfamethoxazole is a common antibiotic used to treat urinary tract infections, as well as a prophylactic agent in HIV patients with low CD4 counts. Exceedingly rare are stones consisting purely of its metabolite, N⁴-acetyl-sulfamethoxazole, and management strategies are not well documented in the literature. We present a case of a patient with HIV who was found to have obstructing ureteral calculi composed of 100% N⁴-acetyl-sulfamethoxazole. Our report contributes a unique case of a Bactrim-induced stone in an immunocompromised patient. Similar patients can be prophylactically treated with diuresis and urinary alkalinization, as well as consideration for alternative medication use.

Ceftazidime-related urinary calculi in a young boy: a case report

Certain drugs can cause kidney stones but as far as we are aware, ceftazidime-related urinary calculi have not been previously reported. We report here a case of an 8-year-old boy who developed hydronephrosis secondary to urinary calculi after receiving ceftazidime 2.0 g by intravenous infusion daily for two weeks. Previously, his left kidney showed no signs of disease. A retrograde double J ureteral stent was inserted, ceftazidime terminated, fluids increased and urine alkalised. On day 25, the patient showed no signs of kidney stones or hydronephrosis. Clinicians should be aware of the possibility of ceftazidime-related urinary calculi particularly if patients are receiving long-term treatment.

Antibiotic Use and Risk of Incident Kidney Stones in Female Nurses

RATIONALE & OBJECTIVE

The intestinal microbiome may affect urinary stone disease by modulating the amount of oxalate absorbed from the intestine and subsequently excreted in urine. This study sought to explore the association between antibiotics, which alter the intestinal microbiota, and risk for urinary stone disease.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

5,010 women in the Nurses' Health Study (NHS) I and II who had collected 24-hour urine samples.

EXPOSURES

Use of antibiotics during the age range of 40 to 49 (NHS II), 40 to 59 (NHS I), and 20 to 39 years (both cohorts).

OUTCOMES

Incident symptomatic urinary stone disease; urine composition.

ANALYTICAL APPROACH

Cause-specific hazards regression adjusted for age, body mass index, comorbid conditions, thiazide use, and dietary factors. Follow-up was censored at the time of asymptomatic kidney stones, cancer, or death.

RESULTS

Cumulative use of antibiotics for a total of 2 or more months during the age range of 40 to 49 years (NHS II) and 40 to 59 years (NHS II) was associated with significantly higher risk for developing incident stones compared with no use (pooled HR, 1.48; 95% CI, 1.12-1.96). Similar results were found for the period of 20 to 39 years (pooled HR, 1.36; 95% CI, 1.00-1.84). Results were unchanged after excluding participants who reported urinary tract infection with their stone event or as the most common reason for antibiotic use. Urine composition was generally similar across antibiotic groups except for marginally lower urine pH and citrate values among those taking antibiotics for 2 or more months.

LIMITATIONS

Observational design; lack of information for type of antibiotic used; relatively large span of time between antibiotic use and urine collection.

CONCLUSIONS

Use of antibiotics for more than 2 months in early adulthood and middle age is associated with higher risk for urinary stone disease in later life.

Adverse events associated with currently used medical treatments for cystinuria and treatment goals: results from a series of 442 patients in France

OBJECTIVE

To evaluate medical treatments, in terms of adverse events (AEs) and therapeutic goals, in a large series of patients with cystinuria.

PATIENTS AND METHODS

Data from 442 patients with cystinuria were recorded retrospectively. Crystalluria was studied in 89 patients. A mixed-effects logistic regression model was used to estimate how urine pH, specific gravity and cysteine-binding thiols (CBT) correlate with risk of cystine crystalluria.

RESULTS

Alkalizing agents and CBT agents were given to 88.8% (n = 381) and 55.3% (n = 238) of patients, respectively. Gastrointestinal AEs were reported in 12.3%, 10.4% and 2.6% of patients treated with potassium bicarbonate, potassium citrate and sodium bicarbonate, respectively (P = 0.008). The percentages of patients who experienced at least one AE with tiopronin (24.6%) and with D-penicillamine (29.5%) were similar (P = 0.45). Increasing urine pH and decreasing urine specific gravity significantly reduced the risk of cystine crystalluria, whereas D-penicillamine and tiopronin treatments did not reduce this risk (odds ratio [OR] 1 for pH ≤6.5; OR 0.52 [95% confidence interval {95% CI} 0.28-0.95] for 7.0 <pH ≤7.5, P = 0.03; OR 0.26 [95% CI 0.13-0.53] for 7.5 < pH ≤8.0, P <0.001; OR 1 for specific gravity ≤1.005 OR 5.76 [95% CI 1.45-22.85] for 1.006 ≤ specific gravity ≤1.010, P = 0.01; and OR 11.06 [95% CI 2.76-44.26] for 1.011 ≤ specific gravity ≤ 1.014, P < 0.001). Increased urine pH significantly increased the risk of calcium phosphate crystalluria (OR 1 for pH≤ 6.5; OR 6.09 [95% CI 2.15-17.25] for pH >8.0, P <0.001).

CONCLUSION

Adverse events were frequent with D-penicillamine and tiopronin. Alkaline hyperdiuresis was well tolerated and reduced cystine crystalluria. Urine specific gravity ≤1.005 and urine pH >7.5, while warning about calcium-phosphate crystallization, should be the goals of medical therapy.

Multidimensional Analysis of Urinary Stone Diseases in Pediatric Patients

Objectives:

Urinary tract stones are less common in children than in adults. Determining the etiology is the most important step to achieve successful treatment and prevent future recurrence. The aim of this study was to investigate the clinical characteristics and possible risk factors for urinary stone disease in pediatric patients.

Methods:

The data of 126 patients with urinary stone disease who were treated in a pediatric nephrology clinic between 2000 and 2014 were analyzed retrospectively. A total 126 patients were enrolled in the study: 70 (55%) male and 56 (45%) female patients were included. The complaints, age of diagnosis, family histories, and stone location were examined. Direct urine microscopic examination, complete urinalysis, and urine culture were performed for all of the patients. Calcium, uric acid, oxalate, citrate, magnesium, and cystine levels were measured in urine collected in a 24-hour period. Serum electrolyte, blood urea nitrogen, creatinine, calcium, phosphorus, uric acid, and albumin levels were measured. Urinary ultrasound was performed. Stone analysis was conducted using the X-ray diffraction method. The mean age of the patients was 55 months (range: 1-162 months) at presentation.

Results:

In all, 34% of the patients had a family history of urinary stone disease. The rate of previous urinary tract infection was 26%. It was determined that 34% of the patients had been taking vitamin D and 5% had been taking a high dose. Metabolic risk factors determined were: hypercalciuria in 41%, hypocitraturia in 30%, hyperoxaluria in 14%, hyperuricosuria in 10%, and cystinuria in 5%. Among the group, 81% of the patients had kidney stones, 6.5% had ureter stones, and 2.5% had bladder stones. Furthermore, it was determined that 45% of the stones were composed of calcium oxalate, 35% had calcium phosphate stones, 14.2% had uric acid stones, and 13.3% had cystine stones. In 52% of the cases, extracorporeal shock wave lithotripsy was performed, and 71% underwent surgical treatment.

Conclusion:

Metabolic evaluation and stone analysis should be performed to prevent future recurrences in children with urinary stone disease and lifelong follow-up should be emphasized.

Interest of URS-L in the Treatment of Ureterolithiasis in Preschool Children

Urolithiasis can affect all children even preschool ones. Diagnostic difficulties in the youngest children are due to the problems in locating pain and determining its character and severity. In keeping with the ALARA (As Low As Reasonably Achievable) protocol, the number of imaging tests possible to perform is very limited. Ultrasound is the first line exam of choice. After diagnosis of the presence of a stone, ESWL (Extracorporeal Shock Wave Lithotrypsy) should always be considered and offered to parents due to its high effectiveness and minimal invasiveness. If ESWL is contraindicated or not well-accepted by parents, authors suggest another minimal invasive approach: URS-L (Uretherorenoscopy-Lithotrypsy). Our study clinically analyzes 87 children, which were treated between 2009 and 2017 using the URS-L procedure. URS-L treatments were performed using Lithoclast until 2009, and after that time, using the holmium laser Ho:YAG. The overall effectiveness of treatments was 93.3%. There was no failure in the access to the stones. A macroscopic hematuria (Clavien-Dindo I grade) was observed through the second post-operative day in 9.2% of treated patients. No urosepsis was observed. Full metabolic evaluation was performed on all patients. Children remained under constant urological and nephrological observation. A recurrence of urolithiasis was observed in 35.6% of the cases. Treating ureteral lithiasis in young infants remains a big challenge. Our series shows that modern minimal invasive techniques used by very experienced pediatric urologists in high volume centers gives excellent results. In most cases, surgery should no longer need to be an option.

Oxalate transport by the mouse intestine in vitro is not affected by chronic challenges to systemic acid-base homeostasis

In rats, we recently showed how a chronic metabolic acidosis simultaneously reduced urinary oxalate excretion and promoted oxalate secretion by the distal colon leading to the proposition that acid-base disturbances may trigger changes to renal and intestinal oxalate handling. The present study sought to reproduce and extend these observations using the mouse model, where the availability of targeted gene knockouts (KOs) would offer future opportunities to reveal some of the underlying transporters and mechanisms involved. Mice were provided with a sustained load of acid (NH₄Cl), base (NaHCO₃) or the carbonic anhydrase inhibitor acetazolamide (ATZ) for 7 days after which time the impacts on urinary oxalate excretion and its transport by the intestine were evaluated. Mice consuming NH₄Cl developed a metabolic acidosis but urinary oxalate was only reduced 46% and not statistically different from the control group, while provision of NaHCO₃ provoked a significant 2.6-fold increase in oxalate excretion. For mice receiving ATZ, the rate of urinary oxalate excretion did not change significantly. Critically, none of these treatments altered the fluxes of oxalate (or chloride) across the distal ileum, cecum or distal colon. Hence, we were unable to produce the same effects of a metabolic acidosis in mice that we had previously found in rats, failing to find any evidence of the 'gut-kidney axis' influencing oxalate handling in response to various acid-base challenges. Despite the potential advantages offered by KO mice, this model species is not suitable for exploring how acid-base status regulates oxalate handling between the kidney and intestine.

Drug-Induced Kidney Stones and Crystalline Nephropathy: Pathophysiology, Prevention and Treatment

Drug-induced calculi represent 1-2% of all renal calculi. The drugs reported to produce calculi may be divided into two groups. The first one includes poorly soluble drugs with high urine excretion that favour crystallisation in the urine. Among them, drugs used for the treatment of patients with human immunodeficiency, namely atazanavir and other protease inhibitors, and sulphadiazine used for the treatment of cerebral toxoplasmosis, are the most frequent causes. Besides these drugs, about 20 other molecules may induce nephrolithiasis, such as ceftriaxone or ephedrine-containing preparations in subjects receiving high doses or long-term treatment. Calculi analysis by physical methods including infrared spectroscopy or X-ray diffraction is needed to demonstrate the presence of the drug or its metabolites within the calculi. Some drugs may also provoke heavy intra-tubular crystal precipitation causing acute renal failure. Here, the identification of crystalluria or crystals within the kidney tissue in the case of renal biopsy is of major diagnostic value. The second group includes drugs that provoke the formation of urinary calculi as a consequence of their metabolic effects on urinary pH and/or the excretion of calcium, phosphate, oxalate, citrate, uric acid or other purines. Among such metabolically induced calculi are those formed in patients taking uncontrolled calcium/vitamin D supplements, or being treated with carbonic anhydrase inhibitors such as acetazolamide or topiramate. Here, diagnosis relies on a careful clinical inquiry to differentiate between common calculi and metabolically induced calculi, of which the incidence is probably underestimated. Specific patient-dependent risk factors also exist in relation to urine pH, volume of diuresis and other factors, thus providing a basis for preventive or curative measures against stone formation.

Review of the Diagnosis and Treatment of Periodic Paralysis

Periodic paralyses (PPs) are rare neuromuscular disorders caused by mutations in skeletal muscle sodium, calcium, and potassium channel genes. PPs include hypokalemic paralysis, hyperkalemic paralysis, and Andersen‐Tawil syndrome. Common features of PP include autosomal dominant inheritance, onset typically in the first or second decades, episodic attacks of flaccid weakness, which are often triggered by diet or rest after exercise. Diagnosis is based on the characteristic clinic presentation then confirmed by genetic testing. In the absence of an identified genetic mutation, documented low or high potassium levels during attacks or a decrement on long exercise testing support diagnosis. The treatment approach should include both management of acute attacks and prevention of attacks. Treatments include behavioral interventions directed at avoidance of triggers, modification of potassium levels, diuretics, and carbonic anhydrase inhibitors. Muscle Nerve57: 522–530, 2018

Bridging the boundaries between scientists and clinicians-mechanistic hypotheses and patient stories in risk assessment of drugs

The cultural divide between scientists and clinicians has been described as undermining the advance of medical science, by hindering the production of practice-relevant research and of research-informed clinical decisions. Here, I consider the field of post-marketing risk assessment of drugs as an example of strict interdependence between basic biomedical research, clinical research, and clinical evaluation and show how it would benefit from a closer collaboration between scientists and clinicians. The risk assessment of drugs after their marketing relies on spontaneous adverse effect reports to drug agencies and on peer-reviewed case reports. I emphasize the importance of qualitative analysis of such reports for the improvement of mechanistic understanding of harmful effects of drugs. I argue that mechanistic explanations of drug effects are at least as important as determination of their frequency, in order to establish causation. An ideal risk assessment, then, verifies not only the frequency of undesired effects but also why and how the harm happens. For this purpose, the frequency or novelty of the unintended outcome, although contextually indicative, should not determine the epistemic value of a report. Details about the context that generated an unexpected outcome, instead, can offer the chance of improving causal understanding about how the intervention works. This is illustrated through examples from medical research. Mechanistic understanding is a domain of joint collaboration among (1) clinicians, in charge of detailed, qualitative reporting of patient stories about side effects, (2) qualitative clinical researchers, in charge of analyzing clinical contexts or harmful effects and formulating explanatory hypotheses, and (3) basic biomedical researchers, in charge of verifying such hypotheses. In addition, direct information flow can on one side focus clinicians' attention on knowledge gaps about drugs/effects where more research is needed, while on the other side create a more contextualized concept of mechanism among scientists.

Effect of Calcitriol Supplementation on Blood Pressure in Older Adults

Recent studies suggest that vitamin D plays an important role in the control of blood pressure. Unfortunately, because older adults are more likely to have low 25-hydroxyvitamin-D [25(OH)D] levels, this study investigated whether calcitriol supplementation reduces blood pressure in older adults with hypertension. The design was a double-blind placebo-controlled randomized clinical trial with 36 randomly assigned subjects (71.7 ± 10 years). Blood pressure and serum levels of 25(OH)D before and after calcitriol intervention (1,000 IU daily for 6 weeks; n = 22) or placebo (n = 23) for 6 weeks were analyzed. At the end of the study, the calcitriol group presented a significant decrease of systolic blood pressure [20.25 mmHg (p = 0.001)] and diastolic blood pressure [7 mmHg (p = 0.01)], compared with the placebo group. In conclusion, 1,000 IU/day of calcitriol for 6 weeks efficiently reduced systolic and diastolic blood pressure levels in this population of older adults presenting with high blood pressure (Clinical Trial Approbation NCT02047799).

Sulfadiazine-Induced Obstructive Nephropathy Presenting with Upper Urinary Tract Extravasation

Background: Obstructive nephropathy is an uncommon side effect of sulfadiazine, which is used for the treatment of toxoplasmosis. We present a case of acute renal colic and urine extravasation of a patient shortly after she was started on this medication. Case Presentation: A 31-year-old female presented with acute renal colic 2 weeks after starting treatment with sulfadiazine and pyrimethamine for ocular toxoplasmosis. Results: A noncontrast computed tomography revealed left hydronephrosis and fluid located around the kidney and in the left gutter. There were no urinary stones. Administration of intravenous contrast revealed significant urine extravasation at the level of the ureteropelvic junction. Intravenous contrast injection confirmed that the extravasation consisted of urine leakage at the ureteropelvic junction. Her clinical condition improved with the insertion of an internal stent, which was left in place for 4 weeks. A retrograde pyelography performed at the time of the internal stent removal ruled out persistent extravasation and filling defects in the left upper urinary tract. Considering the clinical circumstances and the imaging results, it appears that this is a first reported case of sulfadiazine-induced obstructive uropathy associated with urine extravasation. Conclusion: Although rare, obstructive uropathy related to sulfadiazine medication should be promptly suspected, diagnosed, and treated. Patients should be instructed to substantially increase their liquid intake while on that medication.

Comparative evaluation of ceftriaxone- and cefotaxime-induced biliary pseudolithiasis or nephrolithiasis: A prospective study in 154 children

Background:

Biliary lithiasis, or sludge, and nephrolithiasis have been reported as a possible complication of ceftriaxone therapy. However, no study related to cefotaxime-induced biliary pseudolithiasis or nephrolithiasis was observed in the literature. Therefore, we investigated the comparative formation of biliary pseudolithiasis and nephrolithiasis after cefotaxime and ceftriaxone therapies.

Methods:

The patients treated with ceftriaxone or cefotaxime were enrolled during the study period. Ultrasound imaging of the biliary and urinary tract was performed in all patients before and after the treatment. The patients with a positive sonographic finding at the end of treatment were followed up with monthly ultrasonography for 3 months.

Results:

The present study showed that abnormal biliary sonographic findings were demonstrated in 18 children (20.9%) treated with ceftriaxone, 13 (15.1%) had biliary lithiasis, 5 (5.8%) had biliary sludge and 1 (1.2%) had nephrolithiasis. Abnormal biliary sonographic findings were demonstrated in only four (5.9%) children treated with cefotaxime who had biliary sludge and only one (1.5%) had nephrolithiasis. It was observed that older age was at significantly higher risk of developing biliary sludge or stone formation. Receiver operating characteristic analysis was performed to determine the residual risk and analysis found that 4.5 years was the cut-off value for age.

Conclusions:

The present study is unique in the literature for reporting for the first time gall bladder sludge and nephrolithiasis associated with cefotaxime use. Therefore, patients treated with cefotaxime should be monitored for serious complications like patients treated with ceftriaxone. Nevertheless, if third-generation cephalosporin is used, cefotaxime is recommended to be used rather than ceftriaxone.

Structural characterization and vibrational studies of human urinary stones from Istanbul, Turkey

Seven human urinary stones were collected from urinary bladders of patients hailing from Istanbul, Turkey. Their XRD, EDX, FT-IR and FT-Raman spectra as well as SEM images have been recorded to determine their chemical compositions, morphologies, crystal structures, and crystallite sizes. XRD and vibrational (FT-IR and FT-Raman) analyses indicate that six out of the seven stones have identical contents. The ratios of organic and inorganic contents of the stones have been determined by their thermogravimetric analyses. The stones have been found to contain calcium oxalate monohydrate and apatite as the major components.

[Mineral-based alkaline waters' prescription in France: Patients are the key point for both nephrologists and urologists]

Alkali therapy is frequently used during chronic kidney disease and nephrolithiasis: nephrologists and urologists are the key operators. Very few is known about the underlying conditions of such a prescription: the aim of this study was to delineate those determinants. We conducted a prospective survey where French nephrologists and urologists were involved. Responders were without gender distinction and principally nephrologists. Prescription frequency was associated with gender (women), specialty (nephrologists), indications and perceived efficiency. Urologists prescribe more often during nephrolithiasis and nephrologists during chronic kidney disease. Urologists were more expert (by scoring on mineral-based alkaline waters compositions knowledge). By multivariate analysis, prescription frequency is associated with gender (women), indications and perceived efficiency by prescribers, which is itself influenced by feedback from patients. These results could have been influenced by a huge representation of nephrologists but foster physicians to go on listening to feedback from patients, due to a lack of clinical trials on the efficiency of mineral-based alkaline waters in such a field. Finally, physicians' education (especially young nephrologists) on mineral-based alkaline waters should be intensified.

Kidney stone analysis: "Give me your stone, I will tell you who you are!"

INTRODUCTION

Stone analysis is an important part in the evaluation of patients having stone disease. This could orientate the physician toward particular etiologies.

MATERIAL AND METHODS

Chemical and physical methods are both used for analysis. Unfortunately, chemical methods often are inadequate to analyze accurately urinary calculi and could fail to detect some elements into the stone. Physical methods, in counterpart, are becoming more and more used in high-volume laboratories. The present manuscript will provide a review on analytic methods, and review all the information that should be included into an appropriate morpho-constitutional analysis.

CONCLUSION

This report can supply an excellent summarization of the stone morphology and give the opportunity to find specific metabolic disorders and different lithogenic process into the same stone. Here, specific chemical types with their different crystalline phases are shown in connection with their different etiologies involved.

Is nephrolithiasis an unrecognized extra-articular manifestation in ankylosing spondylitis? A prospective population-based Swedish national cohort study with matched general population comparator subjects

Background

Ankylosing spondylitis (AS) is associated with several extra-articular manifestations. Nephrolithiasis (NL) has not been recognized as one of those, however, several factors known to increase the risk of NL are at play in AS patients. The objective was to estimate rates and predictors of NL in Swedish patients with AS compared to the general population.

Methods and Findings

We performed a prospective population-based nationwide cohort study based on linkage of data from Swedish registries. 8,572 AS patients were followed for 49,258 person-years (py) and 39,639 matched general population comparators were followed for 223,985 py. Patients were followed prospectively together with comparator subjects from January 2001 through December 2009. The first occurrence of NL during follow-up was the primary outcome. Hazard Ratios (HR) were used to compare these rates adjusting for comorbidities and treatment, and to assess predictors for NL. Mean age at study entry was 46 years (inter quartile range 36–56 years), 65% were males. Based on 250 vs. 466 NL events, the adjusted HR of NL in AS patients was 2.1 (95%CI 1.8 to 2.4). Predictors of NL within the AS group included prior diagnosis of inflammatory bowel disease (IBD) (HR 2.3; 95%CI 1.7 to 3.3), prior diagnosis of NL (HR 16.4; 95%CI 11.5 to 23.4), and patients receiving anti-TNF treatment (HR 1.6; 95%CI 1.2 to 2.1). Male sex was a risk factor for NL both in AS patients and in the general population.

Limitations

The risk for residual confounding and inability to study the chemical nature of NL were considered the main limitations of the study.

Conclusions

Patients with AS are at increased risk of NL, which may be considered a novel extra-articular manifestation. Previous history of NL, IBD, AS disease severity and male sex were identified as predictors of NL in AS.

Induced urinary crystal formation as an analytical strategy for the prediction and monitoring of urolithiasis and other metabolism-related disorders

Crystal formation reflects the entire composition of the surrounding solution. In case of urolithiasis, induced crystal formation in native urine has led to the development of the Bonn-Risk-Index (BRI), a valuable tool to quantify an individual's risk of calcium oxalate urolithiasis. If the progression of a disease is associated with characteristic changes in the activities of urinary components, this leads to an altered urinary crystallisation capacity. Therefore, the results of induced urinary crystal formation can be used to detect and monitor any disease linked to the altered urinary composition. Since crystal formation inherently takes into account the entire urinary composition, the influence of the disease on individual urinary parameters does not have to be known in order to monitor the consequent pathologic alterations. In this paper, we review the background of urinary crystal formation analysis and describe its established application in urolithiasis monitoring as well as potential further fields of clinical application.

Acute renal failure after ingestion of guaifenesin and dextromethorphan

BACKGROUND

Guaifenesin is a common nonprescription medication that has been implicated in drug-induced nephrolithiasis. Dextromethorphan, a nonprescription antitussive found in some guaifenesin-containing preparations, is increasingly recognized as a substance of abuse by many youth and young adults. Renally excreted medications known to have poor solubility in urine have the potential to precipitate when ingested in large quantity, leading to acute obstruction of the ureters and renal failure.

OBJECTIVE

We describe the case of a 22-year-old male who developed severe bilateral flank pain, hematuria, and oliguria after an isolated recreational ingestion of guaifenesin and dextromethorphan.

CASE REPORT

The patient was found to have bilateral ureteral obstruction and acute renal failure, suspected to be secondary to precipitation of medication metabolites in the urine.

CONCLUSIONS

This case highlights the potential for acute renal failure secondary to guaifenesin and dextromethorphan abuse.

HIV medication-based urolithiasis

Drug-induced renal calculi represent 1–2% of all renal calculi. In the last decade, drugs used for the treatment of HIV-infected patients have become the most frequent cause of drug-containing urinary calculi. Among these agents, protease inhibitors (PIs) are well known to induce kidney stones, especially indinavir and atazanavir, and more recently darunavir. Urolithiasis attributable to other PIs has also been reported in clinical cases such as those during non-PI use. Antiretroviral drug-induced calculi deserve consideration because most of them are potentially preventable. This article summarizes the diagnosis, epidemiology, prevention and management of antiretroviral drug-induced urolithiasis.