Risk of Symptomatic Kidney Stones During and After Pregnancy

Urinary Oxalate Excretion During Pregnancy in Primary Hyperoxaluria Type 1: A Report of 4 Cases

Primary hyperoxaluria (PH) is a rare genetic disorder characterized by excessive oxalate production because of specific gene defects. PH1 is the most prevalent type, causing recurrent kidney stone disease and often leading to chronic kidney disease and kidney failure. Our previous study suggested that pregnancy did not adversely affect kidney function in female patients with PH. In this study, we identified 4 PH1 cases with urinary oxalate (UOx) measurements during pregnancy from the Rare Kidney Stone Consortium and Oxalosis and Hyperoxaluria Foundation PH registry to investigate UOx levels during pregnancy in patients with PH1. The PH Registry is approved by the Institutional Review Board of Mayo Clinic (Rochester, MN). All 4 showed a decrease in UOx during pregnancy when compared with before pregnancy and after delivery. These findings contrast with those of the general population, in which the UOx tends to increase during pregnancy because of a simultaneous physiological increase in the glomerular filtration rate. Elucidating the mechanism underlying reduced UOx during pregnancy in PH1 could suggest novel PH therapies. These findings could also affect the clinical management and have implications regarding the safety of withholding novel PH1-directed molecular therapies that currently have uncertain safety profiles during pregnancy. We highlight the need for additional data on urinary changes in patients with PH and other populations while pregnant to clarify changes in UOx throughout pregnancy.

In focus: perplexing increase of urinary stone disease in children, adolescent and young adult women and its economic impact

Background

Urinary stone disease (USD) historically has affected older men, but studies suggest recent increases in women, leading to a near identical sex incidence ratio. USD incidence has doubled every 10 years, with disproportionate increases amongst children, adolescent, and young adult (AYA) women. USD stone composition in women is frequently apatite (calcium phosphate), which forms in a higher urine pH, low urinary citrate, and an abundance of urinary uric acid, while men produce more calcium oxalate stones. The reasons for this epidemiological trend are unknown.

Methods

This perspective presents the extent of USD with data from a Canadian Province and a North American institution, explanations for these findings and offers potential solutions to decrease this trend. We describe the economic impact of USD.

Findings

There was a significant increase of 46% in overall surgical interventions for USD in Ontario. The incidence rose from 47.0/100,000 in 2002 to 68.7/100,000 population in 2016. In a single United States institution, the overall USD annual unique patient count rose from 10,612 to 17,706 from 2015 to 2019, and the proportion of women with USD was much higher than expected. In the 10-17-year-old patients, 50.1% were girls; with 57.5% in the 18-34 age group and 53.6% in the 35-44 age group. The roles of obesity, diet, hormones, environmental factors, infections, and antibiotics, as well as the economic impact, are discussed.

Interpretation

We confirm the significant increase in USD among women. We offer potential explanations for this sex disparity, including microbiological and pathophysiological aspects. We also outline innovative solutions - that may require steps beyond typical preventive and treatment recommendations.

Associations of exposure to heavy metal mixtures with kidney stone among U.S. adults: A cross-sectional study

Assessing the effects of heavy metals (HMs) on kidney stone is often limited to analyzing individual metal exposures, with studies on the effects of exposure to mixtures of HMs being scarce. To comprehensively evaluate the relationship between exposure to mixed HMs and kidney stones, we analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 2007-2016, which included 7809 adults. We used multiple statistical methods, including multiple logistic regression models, weighted quantile sum (WQS) regression, quantile g-computation (qgcomp) and bayesian kernel machine regression (BKMR), to assess the association between single HM and mixed exposure to HMs and kidney stones. Firstly, in single exposure analysis, urinary cadmium (Cd) and cobalt (Co) demonstrated a positive association with the risk of kidney stones. Secondly, various other approaches consistently revealed that mixed exposure to HMs exhibited a positive association with kidney stone risk, primarily driven by Cd, Co, and barium (Ba) in urine, with these associations being particularly notable among the elderly population. Finally, both BKMR and survey-weighted generalized linear models consistently demonstrated a significant synergistic effect between urinary Co and urinary uranium (Ur) in elevating the risk of kidney stones. Overall, this study provides new epidemiological evidence that mixed exposure to HMs is associated with an increased risk of kidney stones. Further prospectively designed studies are needed to confirm these findings.

Care plan for individuals at risk for preeclampsia: shared approach to education, strategies for prevention, surveillance, and follow-up

Preeclampsia is a multisystemic disorder of pregnancy that affects 250,000 pregnant individuals in the United States and approximately 10 million worldwide per annum. Preeclampsia is associated with substantial immediate morbidity and mortality but also long-term morbidity for both mother and offspring. It is now clearly established that a low dose of aspirin given daily, beginning early in pregnancy modestly reduces the occurrence of preeclampsia. Low-dose aspirin seems safe, but because there is a paucity of information about long-term effects on the infant, it is not recommended for all pregnant individuals. Thus, several expert groups have identified clinical factors that indicate sufficient risk to recommend low-dose aspirin preventive therapy. These risk factors may be complemented by biochemical and/or biophysical tests that either indicate increased probability of preeclampsia in individuals with clinical risk factors, or more importantly, identify increased likelihood in those without other evident risk. In addition, the opportunity exists to provide this population with additional care that may prevent or mitigate the short- and long-term effects of preeclampsia. Patient and provider education, increased surveillance, behavioral modification, and other approaches to improve outcomes in these individuals can improve the chance of a healthy outcome. We assembled a group with diverse, relevant expertise (clinicians, investigators, advocates, and public and private stakeholders) to develop a care plan in which providers and pregnant individuals at risk can work together to reduce the risk of preeclampsia and associated morbidities. The plan is for care of individuals at moderate to high risk for developing preeclampsia, sufficient to receive low-dose aspirin therapy, as identified by clinical and/or laboratory findings. The recommendations are presented using the GRADE methodology with the quality of evidence upon which each is based. In addition, printable appendices with concise summaries of the care plan's recommendations for patients and healthcare providers are provided. We believe that this shared approach to care will facilitate prevention of preeclampsia and its attendant short- and long-term morbidity in patients identified as at risk for development of this disorder.

Outpatient Antibiotic Use is Not Associated with an Increased Risk of First-Time Symptomatic Kidney Stones

SIGNIFICANCE STATEMENT

Antibiotics modify human microbiomes and may contribute to kidney stone risk. In a population-based case-control study using 1247 chart-validated first-time symptomatic kidney stone formers and 4024 age- and sex-matched controls, the risk of kidney stones was transiently higher during the first year after antibiotic use. However, this risk was no longer evident after adjustment for comorbidities and excluding participants with prior urinary symptoms. Findings were consistent across antibiotic classes and the number of antibiotic courses received. This suggests that antibiotics are not important risk factors of kidney stones. Rather, kidney stones when they initially cause urinary symptoms are under-recognized, resulting in antibiotic use before a formal diagnosis of kidney stones ( i.e. , reverse causality).

BACKGROUND

Antibiotics modify gastrointestinal and urinary microbiomes, which may contribute to kidney stone formation. This study examined whether an increased risk of a first-time symptomatic kidney stone episode follows antibiotic use.

METHODS

A population-based case-control study surveyed 1247 chart-validated first-time symptomatic kidney stone formers with a documented obstructing or passed stone (cases) in Olmsted County, Minnesota, from 2008 to 2013 and 4024 age- and sex-matched controls. All prescriptions for outpatient oral antibiotic use within 5 years before the onset of symptomatic stone for the cases and their matched controls were identified. Conditional logistic regression estimated the odds ratio (OR) of a first-time symptomatic kidney stone across time after antibiotic use. Analyses were also performed after excluding cases and controls with prior urinary tract infection or hematuria because urinary symptoms resulting in antibiotic prescription could have been warranted because of undiagnosed kidney stones.

RESULTS

The risk of a symptomatic kidney stone was only increased during the 1-year period after antibiotic use (unadjusted OR, 1.31; P = 0.001), and this risk was attenuated after adjustment for comorbidities (OR, 1.16; P = 0.08). After excluding cases and controls with prior urinary symptoms, there was no increased risk of a symptomatic kidney stone during the 1-year period after antibiotic use (unadjusted OR, 1.04; P = 0.70). Findings were consistent across antibiotic classes and the number of antibiotic courses received.

CONCLUSIONS

The increased risk of a first-time symptomatic kidney stone with antibiotic use seems largely due to both comorbidities and prescription of antibiotics for urinary symptoms. Under-recognition of kidney stones that initially cause urinary symptoms resulting in antibiotic use may explain much of the perceived stone risk with antibiotics ( i.e. , reverse causality).

A comparison of adverse pregnancy events between ureteral stents and percutaneous nephrostomy tubes in the treatment of nephrolithiasis during pregnancy: A propensity score-matched analysis of a large multi-institutional research network

PURPOSE

To investigate rates of adverse pregnancy events associated with the use of percutaneous nephrostomy tubes (PCN) versus ureteral stents in the treatment of nephrolithiasis during pregnancy.

METHODS

We queried the TriNetX Diamond Network database to evaluate pregnant women (ICD-10 Z34, O09) with a history of nephrolithiasis (N20-23) who underwent a PCN (CPT 50432) or ureteral stent (52332) placement up to 6 months before delivery (O80-82). We controlled for the following potentially confounding variables through propensity score matching: age, race, ethnicity, acute pyelonephritis (N10), infections of the genitourinary tract in pregnancy (O23.0), and other sepsis (A41) at the time of stent or PCN placement.

RESULTS

We identified 2,999 pregnant women who underwent ureteral stent placement and 321 who underwent PCN. Following propensity score matching, we found there to be no significant difference in the rate of premature labor or delivery (aOR 1.08, 95% CI 0.735-1.588), premature rupture of membranes (0.889, 0.453-1.743), intrauterine infection (0.906, 0.379-2.165), or c-Sect. (0.825, 0.408-1.667). Within 6 months of their initial procedure, women with a ureteral stent experienced a significantly decreased rate of subsequent urinary tract infection (UTI) or pyelonephritis (0.52, 0.38-0.71), inpatient hospital stay (0.40, 0.26-0.64), emergency department visit (0.65, 0.48-0.89), and repeat exchange procedure (0.70, 0.51-0.96).

CONCLUSION

In the treatment of nephrolithiasis during pregnancy, PCN versus ureteral stent placement does not confer a significant difference in rates of adverse pregnancy events. However, ureteral stent placement was associated with a lower incidence of hospital admissions, emergency department visits, exchange procedures, and new UTIs or pyelonephritis.

Ureteroscopic lithotripsy of ureteric stone using thulium fiber laser in a pregnant patient, case report

Nephrolithiasis represents a common cause of non-obstetrical abdominal pain during pregnancy with 1 out of 200 pregnancies being affected. 20%-30% of patients require ureteroscopy. Many studies were done on safety of holmium:yttrium-aluminium-garnet (YAG) during pregnancy but none on Thulium Fiber Laser (TFL). To our knowledge, this is the first reported case of pregnant patient with nephrolithiasis that was treated using ureteroscopy and TFL. We present a 28 years old pregnant woman that presented to our hospital with a left distal ureteric stone. Patient underwent URS and lithotripsy using TFL. The procedure was tolerated with no complications.

Detection of Cadmium and Lead in Kidney Stones. Associations with Patient Demographics, Stone Composition, and Smoking

BACKGROUND

Kidney stones are a highly prevalent disease worldwide. Additionally, both environmental and occupational exposure to Pb and Cd continue to be prevalent globally and can result in renal toxicity. The objective of this study was to examine the potential presence of Pb and Cd in kidney stones, and to assess for correlation with demographic factors including smoking, gender, age, and kidney stone matrix composition.

METHODS

Patient kidney stones (n = 96) were analyzed using Fourier transform infrared spectroscopy to identify the stone constituents. Cd and Pb concentrations (µg/g) were determined by inductively coupled plasma mass spectrometry. Cd and Pb concentrations were correlated using bivariable and multivariable statistical analysis with demographic factors (age, gender, smoking status), and kidney stone composition.

RESULTS

Kidney stone Cd (median 0.092 µg/g, range 0.014 to 2.46) and Pb concentrations (median 0.95 µg/g, range 0.060 to 15.4) were moderately correlated (r = 0.56, P < 0.0001). Cd concentrations were positively associated with patient history of smoking, patient age, and calcium oxalate monohydrate levels while negatively associated with struvite and uric acid/uric acid dihydrate. Pb concentrations were positively associated with females and apatite levels while negatively associated with uric acid/uric acid dihydrate. After holding constant other stone type composition levels, smoking status, and age, both Pb and Cd were positively associated with apatite and negatively associated with uric acid/uric acid dihydrate, struvite, and calcium carbonate.

CONCLUSIONS

Cd and Pb kidney stone concentrations are associated with specific kidney stone types. Cd and Pb kidney stone concentrations are both associated with smoking.

Subcutaneous infusion of rhPTH 1-34 during pregnancy and nursing in a woman with autosomal dominant hypoparathyroidism 1

We report a successful pregnancy in a young woman with autosomal dominant hypoparathyroidism type 1 (ADH1) due to an activating mutation of the calcium sensing receptor (CASR) (c.2519C>T; p.Ala840Val) who was treated with recombinant human parathyroid hormone (rhPTH)^1-34 delivered via continuous subcutaneous infusion using an OmniPod pump. She experienced no tetany or hospitalizations during the pregnancy. Serum calcium levels ranged from 7.2 to 9.8 mg/dL. Due to mild preeclampsia, her infant was delivered at 37 weeks. There were no physical anomalies. The patient continued pump therapy while nursing her daughter, who was ultimately confirmed to have the same CASR mutation. Breastfeeding appeared to protect the infant from significant hypocalcemia without the need for calcium or calcitriol supplementation until weaning at a year of age. A role for parathyroid hormone-related protein (PTHrP) is suggested.