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

Sulfasalazine related nephrolithiasis in patients with rheumatoid arthritis and ankylosing spondylitis

Background Sulfasalazine (SSZ) is an anti-inflammatory and immunomodulatory drug used to treat many inflammatory diseases. Bacteria in the gut metabolize SSZ to active 5-aminosalicylic acid and inactive sulfapyridine. Sulfapyridine can crystallize in the kidney. We aimed to investigate the frequency of nephrolithiasis in patients who were diagnosed with rheumatoid arthritis (RA), ankylosing spondylitis (AS) and who received SSZ treatment retrospectively. Material and Methods We retrospectively analyzed the files of AS and RA patients in the rheumatology outpatient clinic between 2009 and 2018. We identified patients who underwent kidney ultrasonography at least six months after initiation of SSZ. One hundred six patients and 50 healthy adults were included in the study. Results Only eight patients (6 AS, 2 RA) had nephrolithiasis on ultrasonography, but none in the control group (p=0.046). In logistic regression analysis, no correlation was found between gender, age, vitamin D, parathyroid hormone, and urinary calcium excretion with SSZ use (p>0.05). Conclusion Although, it is noteworthy that these patients are prone to stone formation for various reasons. Therefore, paying attention to the patient’s hydration while using these drugs may prevent such side effects.

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.

Risks of solid cancers in elderly persons with osteoarthritis or ankylosing spondylitis

OBJECTIVES

Patients with osteoarthritis and ankylosing spondylitis have lower cancer-related mortality than the general population. We examined risks of solid cancers at 16 sites in elderly patients with knee or hip osteoarthritis (KHOA) or ankylosing spondylitis.

METHODS

In this population-based retrospective cohort study, we used US Medicare data from 1999 to 2010 to identify cohorts of persons with KHOA or ankylosing spondylitis, and a general population group without either condition, who were followed through 2015. We compared cancer incidence among groups, adjusted for age, sex, race, socioeconomic characteristics, geographic region, smoking and comorbidities.

RESULTS

We studied 2 701 782 beneficiaries with KHOA, 13 044 beneficiaries with ankylosing spondylitis, and 10 859 304 beneficiaries in the general population group. Beneficiaries with KHOA had lower risks of cancer of the oropharynx, oesophagus, stomach, colon/rectum, hepatobiliary tract, pancreas, larynx, lung, and ovary than the general population. However, beneficiaries with KHOA had higher risks of melanoma, renal cell cancer, and cancer of the bladder, breast, uterus and prostate. Associations were similar in ankylosing spondylitis, with lower risks of cancer of the oesophagus, stomach, and lung, and higher risks of melanoma, renal cell cancer, and cancer of the renal pelvis/ureter, bladder, breast, and prostate.

CONCLUSION

Lower risks of highly prevalent cancers, including colorectal and lung cancer, may explain lower cancer-related mortality in patients with KHOA or ankylosing spondylitis. Similarities in cancer risks between KHOA and AS implicate a common risk factor, possibly chronic NSAID use.

Spondyloarthritis Patients Suffer Increased Risk of Renal Complications Compared With General Population: A Retrospective Observational Study

The objective of this study was to identify the prevalence and risk factors of renal complications of spondyloarthritis (SpA) patients, and to assess increased risks compared to general people. We conducted a retrospective study enrolled with consecutive SpA patients from an inpatient department and age, sex-matched general population (GP). The renal disorders investigated in this study contained decreased estimated glomerular filtration rate (eGFR), hematuria, proteinuria and nephrolithiasis. A total of 350 admitted SpA patients with complete medical records and 323 age and sex-matched GP were enrolled. Most SpA patients were male (n = 283, 80.9%) and the mean age was 31.61 ± 10.73 years old. Among 350 SpA patients, 29 (8.8%) suffered from hematuria, six (1.8%) suffered from proteinuria, one (0.3%) had decreased eGFR, and 27 (13.0%) presented with nephrolithiasis. The relative risk (RR) of nephrolithiasis in SpA compared to the GP was 2.24 (95% CI, 1.00-4.98), and the RR of renal insufficiency was 2.04 (95% CI, 1.11-3.77). In a univariate analysis, nephrolithiasis was significantly associated with age, age of onset, smoking, extra-articular manifestation and a bamboo spine. Renal insufficiency was significantly associated with age, peripheral manifestation, serum albumin, C-reactive protein and erythrocyte sedimentation rate. In a multivariable analysis, only extra-articular manifestation (OR = 8.43, 95% CI, 1.65-43.06, p = 0.010) and bamboo spine (OR = 3.47, 95% CI, 1.01-12.06, p = 0.049) remained significantly associated with nephrolithiasis. However, no variable was recognized as an independent risk factor for renal insufficiency. Renal complications are more common in SpA patients, with more than two-fold increased risk compared with GP. Extra-articular manifestation and bamboo spine are independent risk factors of renal disease in SpA patients.

Body fatness, diabetes, physical activity and risk of kidney stones: a systematic review and meta-analysis of cohort studies

We conducted a systematic review and meta-analysis to clarify the association between adiposity, diabetes, and physical activity and the risk of kidney stones. PubMed and Embase were searched up to April 22nd 2018 for relevant studies. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random effects models. Thirteen cohort studies were included. The summary relative risk was 1.21 (95% CI 1.12-1.30, I2 = 76%, n = 8) per 5 unit increment in BMI, 1.16 (95% CI 1.12-1.19, I2 = 0%, n = 5) per 10 cm increase in waist circumference, 1.06 (95% CI 1.04-1.08, I2 = 67%, n = 3) per 5 kg increase in weight and 1.12 (95% CI 1.06-1.18, I2 = 86%, n = 3) per 5 kg of weight gain. The summary RR was 1.16 (95% CI 1.03-1.31, I2 = 51%, n = 10) for participants with diabetes compared to participants without diabetes, and 0.93 (95% CI 0.78-1.10, I2 = 80%, n = 4) for high vs. low physical activity. These results suggest a positive association between adiposity and diabetes and the risk of kidney stones, but no association with physical activity.

Nephrolithiasis in ankylosing spondylitis and its relationship with disease assessment scales

OBJECTIVE:

The aim of this study was to investigate the frequency of renal calculi in patients with ankylosing spondylitis (AS) and to determine its relationship with disease assessment variables.

METHODS:

The study was designed retrospectively, and it included a cohort of 320 patients with AS diagnosed using the Modified New York Criteria. A total of 119 patients who underwent renal ultrasonography (USG), in who the erythrocyte sedimentation rate, C-reactive protein, blood calcium, phosphorus, Vitamin D, parathormone, and urinary calcium excretion were measured, and who also had lateral cervical and lumbar radiography in the same time period were extracted from the cohort. All patients’ demographic characteristics and the results of blood and urine tests were recorded. The Ankylosing Spondylitis Disease Activity Index (BASDAI), Ankylosing Spondylitis Functional Index (BASFI), Ankylosing Spondylitis Mobility Index (BASMI), and Modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS) were evaluated in all patients.

RESULTS:

Thirteen of the 119 patients had renal calculi confirmed by USG data. The frequency of nephrolithiasis detected by USG was 10.9% in patients with AS. The disease lasted significantly longer in patients with renal calculi ([nephrolithiasis (+): 18.39±8.72 years; nephrolithiasis (−): 12.02±8.43 years, p=0.01]). The BASMI total score was significantly higher in the group of patients with renal calculi. There was not any significant difference in terms of blood samples, HLA-B27, BASDAI, BASFI, and mSASSS between groups.

CONCLUSION:

The frequency of renal stones is increased in patients with AS compared to healthy population. Especially patients who had AS for a long time and higher BASMI values are more susceptible to renal calculi. It is important to point out that the results of this type of studies would be more reliable if the study is conducted on large patient groups and population-based prevalence.

The Prevalence of Renal Impairment in Patients with Spondyloarthritis: Results from the International ASAS-COMOSPA Study

OBJECTIVE

To assess the prevalence and association of renal dysfunction in patients with spondyloarthritis (SpA).

METHODS

The ASAS-COMOSPA (Assessment of Spondyloarthritis international Society-COMOrbidities in SPondyloArthritis) was an international study (22 participating countries from 4 continents) investigating comorbidities in SpA. Renal function was assessed based on estimated glomerular filtration rate (eGFR) calculated using the Modification of Diet in Renal Disease equation. SpA characteristics and risk factors for renal impairment were collected. Nonsteroidal antiinflammatory drug (NSAID) use was assessed based on current intake (last 3 mos).

RESULTS

Of the 3984 patients recruited, 2098 (52.6%) were analyzed after excluding outliers and patients with no available eGFR measurement [male sex: 63.5%; age: 45.3 yrs; disease duration: 8.6 years; HLA-B27+: 73.1%; Bath Ankylosing Spondylitis Activity Index (BASDAI): 3.6/10]. Overall, 153 patients (5.2%, mean age: 53.6 yrs) exhibited an eGFR < 60 ml/min/1.73 m2. In univariate analysis, renal impairment was associated with age (p < 0.001), HLA-B27 positivity (p = 0.003), several cardiovascular (CV) risk factors (history of hypertension, p < 0.001; systolic blood pressure, p = 0.009; diabetes, p = 0.005; and Framingham risk score, p < 0.001), disease activity scores [BASDAI, p = 0.001; Ankylosing Spondylitis Disease Activity Score-C-reactive protein (ASDAS-CRP), p < 0.001], functional variables (Bath Ankylosing Spondylitis Functional Index, p < 0.001), inflammatory biomarkers (erythrocyte and CRP, both p < 0.001), and NSAID intake since onset of disease (percentage of days, p = 0.008). However, there was no association with disease duration, disease severity, or ASAS-NSAID score. In multivariate analysis, age (45-59 yrs: OR 1.9, > 60 yrs: OR 6.2), HLA-B27 positivity (OR 0.51), and CRP (OR 1.3) remained significantly associated with eGFR < 60 ml/min/1.73 m2.

CONCLUSION

Renal impairment was associated with age, HLA-B27 positivity, and inflammation, though not with CV risk factors, disease severity, or NSAID intake in patients with SpA.

Ankylosing Spondylitis: A Review

Ankylosing spondylitis is a chronic autoimmune inflammatory condition belonging to the spondyloarthropathy category of rheumatic diseases. It typically affects the axial skeleton but may also present with peripheral arthritis and extra-articular features. Ankylosing spondylitis tends to occur in patients under the age of 45 years, has a higher incidence in males, and can lead to disability and reduced quality of life if not adequately treated. Management consists of a multidisciplinary team approach. Although traditional disease modifying anti-rheumatic drugs are less effective for the axial component of this disease, biologic therapies do seem effective. In severe cases, surgery may be warranted.

Incidence of and risk factors for nephrolithiasis in patients with gout and the general population, a cohort study

BACKGROUND

Nephrolithiasis (NL) is known to be associated with gout, although there are few comparative studies on risk and risk factors for NL in gout compared to population cohorts. In this cohort study we investigated: (1) overall incidence of NL in gout (cases) and general population controls; (2) risk and risk factors (common comorbidities and medications) for first-time NL in cases and controls separately.

METHODS

Cases (n = 29,968) and age-matched and sex-matched controls (n = 138,678) were identified from the regional healthcare database in western Sweden (VEGA). The analyzed risk factors (comorbidities and current medication use) for first-time NL, and socioeconomic factors were retrieved from VEGA and other national Swedish registers. For cases, follow up began on 1 January 2006 or on the first diagnosis of gout if this occurred later, and for controls on their index patient's first diagnosis of gout. Follow up ended on death, emigration or 31 December 2012. Incidence rates (IR) per 1000 person-years and hazard ratios (HR) were calculated. The incidence calculations were performed for cases (regardless of prior NL) and their controls. HRs with first occurrence of NL as outcome were calculated only in those without previous NL.

RESULTS

In cases there were 678 NL events (IR: 6.16 events per 1000 person-years (95% CI: 5.70-6.64) and in controls 2125 NL events (IR 3.85 events per 1000 person-years (95% CI: 3.69-4.02), resulting in an age-sex-adjusted incidence rate ratio of 1.60 (95% CI:1.47-1.74). Point estimates for predictive factors were similar in cases and controls, except for a significant interaction for losartan which increased the risk of NL only in controls (HR = 1.49 (95% CI: 1.03-2.14). Loop diuretics significantly decreased the risk of NL by 30-34% in both cases and controls. Further significant predictors of NL in gout cases were male sex, diabetes and obesity and in controls male sex and kidney disease.

CONCLUSIONS

The risk (age and sex adjusted) of NL was increased by 60% in cases compared to controls. None of the commonly used medications increased the risk of NL in gout patients.

Clinical characteristics of importance to outcome in patients with axial spondyloarthritis: protocol for a prospective descriptive and exploratory cohort study

INTRODUCTION

Spondyloarthritis (SpA) is a heterogeneous spectrum of rheumatic diseases with either predominantly axial inflammatory symptoms of the spine and sacroiliac joints or predominantly peripheral arthritis. The two main entities of axial SpA (axSpA) are ankylosing spondylitis or non-radiographic axSpA (nr-axSpA). Tumour necrosis factor-α inhibitors have revolutionised the treatment of patients with axSpA who failed to respond to non-steroidal anti-inflammatory drugs and physical therapy. Chronic pain is common in patients with SpA and may still persist despite the lack of signs of inflammation. This has led researchers to hypothesise that central pain sensitisation may play a role in the generation of chronic pain in SpA. The painDETECT Questionnaire (PDQ) is a screening tool developed to detect neuropathic pain components. The primary objective is to explore the prognostic value of the PDQ regarding treatment response in patients with axSpA 3 months after initiating a biological agent. Secondary aim is to evaluate the impact of extra-articular manifestations, comorbidities and patient-reported outcomes and elucidate if these factors influence treatment response.

METHOD AND ANALYSIS

We will include 60 participants (≥18 years of age) diagnosed with axSpA independent of main entity, who initiate or switch treatment of a biologic. Data will be collected at baseline and at endpoint following Danish clinical practice (≥3 months) of treatment with biologics. We will explore whether the PDQ and other phenotypical patient characteristics are prognostically important for response to biological therapy according to established response criteria like 50% improvement in the Bath Ankylosing Spondylitis Disease Activity Index (50%) and Ankylosing Spondylitis Disease Activity Score.

ETHICS AND DISSEMINATION

The study is approved by the Region of Southern Denmark's Ethics committee (S-20160094) and has been designed in cooperation with patient representatives. The study is registered at clinicaltrials.gov (NCT02948608, pre-results). Dissemination will occur through publication(s) in international peer-reviewed journal(s).

The Risk of Nephrolithiasis Among Patients With Ankylosing Spondylitis: a Population-Based Cohort Study

Objectives

This study aims to investigate the correlation of ankylosing spondylitis (AS) with nephrolithiasis by performing a nationwide population- based cohort study.

Patients and methods

The data used in this retrospective cohort study were collected from the Taiwan National Health Insurance Research database. The study included a total of 3,334 AS patients (1,914 males, 1,420 females; mean age 44.51±16.83 years; range 22 to 79 years) and 13,336 non-AS patients (7,656 males, 5,680 females; mean age 44.27±17.01 years; range 21 to 78 years) who had been followed-up on an average of 6.78 years and 6.75 years, respectively, between January 2000 and December 2008.

Results

The percentage of newly diagnosed nephrolithiasis was 4.8% in all study subjects. However, the percentages of newly diagnosed nephrolithiasis were 5.76% and 4.58% in the AS and non-AS cohorts, respectively. After adjusting the patients' sex, age, urbanization level, and comorbidities, the hazard ratio obtained from our multivariable Cox model was 1.19.

Conclusion

Our study findings indicate that patients with AS are more likely to develop nephrolithiasis than non-AS patients.

Surgical interventions for nephrolithiasis in ankylosing spondylitis and the general population

OBJECTIVE

The aim of this study was to estimate rates and type of definitive surgical interventions for nephrolithiasis in Swedish patients with ankylosing spondylitis (AS) compared to the general population.

MATERIALS AND METHODS

This national prospective cohort study linked data from Swedish population and healthcare registries. Incidence rates and interventions for nephrolithiasis during follow-up in patients with AS were compared to general population comparator (GPC) subjects.

RESULTS

In total, 8572 AS patients were followed for 49,959 person-years and 39,639 matched GPCs were followed for 225,221 person-years. Mean age at study entry was 46 years [interquartile range (IQR) 36-56 years] and 65% were male. In AS patients with a diagnosis of nephrolithiasis during the study period, 29% (72/250) underwent similar intervention for nephrolithiasis compared to 24% (114/466) GPCs (p = 0.21). The incidence rate ratio (RR) in overall AS patients was 2.9 [95% confidence interval (CI) 2.1-3.8] during a median follow-up of 6.2 years (IQR 3.2-8.6 years). With prior diagnosis of nephrolithiasis, the RR for AS patients compared to GPCs was 3.7 (95% CI 1.8-7.7); without prior nephrolithiasis the RR was 2.1 (95% CI 1.5-3.0). Increasing age [odds ratio (OR) 1.02, 95% CI 1.01-1.03], prior nephrolithiasis diagnosis (OR 3.3, 95% CI 1.97-5.62) and atherosclerotic cardiac disease (OR 2.0, 95% CI 1.03-3.91) were identified as predictors of intervention for nephrolithiasis.

CONCLUSIONS

Patients with AS have an almost three-fold increased risk of surgical intervention for kidney stones, with similar management, compared to the general population.