Risk Factors of Renal Involvement Based on Different Manifestations in Patients with Ankylosing Spondylitis

The relationship between long-term use of nonsteroidal anti-inflammatory drugs and kidney function in patients with ankylosing spondylitis

Objective

Although nonsteroidal anti-inflammatory drugs (NSAIDs) are the first-line treatment for ankylosing spondylitis (AS), their effect on kidney function remains unclear. This longitudinal study investigated the correlation between long-term NSAID use and kidney function in patients with AS using electronic medical records.

Methods

The electronic medical records of 1,280 patients with AS collected from a single center between January 2001 and December 2018 were reviewed. The Assessment of Spondyloarthritis International Society (ASAS) NSAID Intake Score was used to determine the cumulative dose of all NSAIDs prescribed for a different time intervals. Each ASAS NSAID Intake Score was obtained for intervals of 6 months, 1 year, 2 years, 3 years, 5 years, and 10 years. The correlation between the ASAS NSAID Intake Score and final estimated glomerular filtration rate (eGFR) for each interval was investigated.

Results

The mean ASAS Intake Scores for 6-month, 1-year, 2-year, 3-year, 5-year, and 10-year intervals were 55.30, 49.28, 44.84, 44.14, 44.61, and 41.17, respectively. At each interval, the pearson correlation coefficients were -0.018 (95% CI -0.031 to -0.006, p=0.004), -0.021 (95% CI -0.039 to -0.004, p=0.018), -0.045 (95% CI -0.071 to -0.019, p=0.001), -0.069 (95% CI -0.102 to -0.037, p<0.001), -0.070 (95% CI -0.114 to -0.026, p=0.002), -0.019 (95% CI -0.099 to 0.062, p=0.645), respectively. There was a very weak negative relationship between ASAS Intake Score and eGFR at each interval.

Conclusion

Long-term NSAID use did not correlate with kidney function based on real-world data in patients with AS.

Investigating the Molecular Mechanism of Qianghuo Shengshi Decoction in the Treatment of Ankylosing Spondylitis Based on Network Pharmacology and Molecular Docking Analysis

Background: Qianghuo Shengshi decoction (QHSSD), a traditional Chinese medicine formula, is used to treat ankylosing spondylitis (AS) in China. The pharmacological mechanism of QHSSD for AS remains to be clarified. In this study, we investigated the molecular mechanisms of QHSSD in the treatment of AS using network pharmacology and molecular docking. Methods: To obtain the chemical components and potential targets of QHSSD, we used the Traditional Chinese Medicine Systematic Pharmacology Database and Analysis Platform (TCMSP) and SwissTargetPrediction. AS potential targets were found in the GeneCards, OMIM, and DisGenets databases. A Venn diagram was used to screen QHSSD and AS common potential targets. The STRING website and Cytoscape software were used to create and analyze protein–protein interactions and component–target networks. The DAVID database was used for the gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Molecular docking was used to visualize drug–target interactions. Results: The component–target network consisted of 119 chemical components and 193 potential targets. QHSSD was implicated in various biological processes, such as inflammation and angiogenesis, and mediated multiple signaling pathways, such as the MAPK signaling pathway. Molecular docking revealed good binding ability between medicarpin, notoptol, vitetrifolin E, and cnidilin and EGFR, TNF-α, ALB, and VEGFA. Conclusions: The chemical compositions, potential targets, and pathways involved in the QHSSD treatment of AS were successfully predicted in this study. This study provides a solid foundation for the selection of drugs to treat AS.

Kidney Disease in Ankylosing Spondylitis: a case series and review of the literature

Abstract Background Kidney disease is a rare manifestation of ankylosing spondylitis (AS) and its pathological alterations remain poorly described. The aim of this study was to investigate the clinical presentation and pathological alterations on kidney biopsy of AS patients and review and discuss the current literature on the issue. Methods: We retrospectively studied the clinical presentation and kidney pathological alterations of 15 Caucasian AS patients submitted to kidney biopsy between October 1985 and March 2021. Results: Patients were predominantly male (66.7%) with median age at the time of kideney biopsy of 47 years [IQR 34 - 62]. Median serum creatinine at presentation was 1.3 mg/dL [IQR 0.9 - 3] and most patients also had either proteinuria (85.7%) and/or hematuria (42.8%). The most common indication for kidney biopsy was nephrotic syndrome (33.3%), followed by acute or rapidly progressive kidney injury (20%) and chronic kidney disease of unknown etiology (20%). Chronic interstitial nephritis (CIN) (n=3) and AA amyloidosis (n=3) were the most common diagnosis. Others included IgA nephropathy (IgAN) (n=2), focal segmental glomerulosclerosis (n=2), membranous nephropathy (n=1), and immune complex-mediated membranoproliferative glomerulonephritis (IC-MPGN)(n=1). Conclusions: We present one of the largest series of biopsy-proven kidney disease in Caucasian AS patients. We found a lower prevalence of IgAN than previously reported in Asian cohorts. We found a higher prevalence of CIN and a lower prevalence of AA amyloidosis than that described in previous series of Caucasian patients. We also present the first case of AS-associated IC-MPGN.

Serum RANKL levels in Chinese patients with ankylosing spondylitis: a meta-analysis

Objective

We aimed to determine the association between serum receptor activator of nuclear factor-kappa B ligand (sRANKL) levels and ankylosing spondylitis (AS) in Chinese patients.

Methods

The PubMed, Cochrane Library, Embase, Chinese Biomedical Database, Web of Science, China National Knowledge Infrastructure, VIP, and Wan Fang databases were searched for studies conducted before October 1, 2020, without language restrictions. STATA version 12.0 and Revman version 5.3 were used to analyze the data. The standard mean differences (SMDs) and corresponding 95% confidence intervals (95% CIs) were calculated.

Results

Twelve clinical case–control studies, including 585 patients with AS and 423 healthy controls, were included. The combined SMD for sRANKL suggested that the sRANKL level was significantly higher in Chinese patients with AS than in healthy controls (SMD: 3.27, 95% CI 2.11–4.43, P < 0.00001). Serum RANKL-related factor osteoprotegerin (OPG) levels (SMD: 0.86, 95% CI 0.09–1.64, P < 0.03) were lower in the Chinese patients with AS than in healthy controls, and the RANKL/OPG ratio (SMD = 1.05, 95% CI 0.64–1.46, P < 0.00001) in Chinese patients with AS was approximately the same as that of healthy controls. Subgroup analysis indicated that patients from North and South China had higher sRANKL levels than controls; the sRANKL levels of patients from South China were higher in the subgroup with a Bath Ankylosing Spondylitis Functional Index (BASFI) of > 4 than those of patients in other subgroups. In terms of duration, patients with AS for > 8 years had higher sRANKL levels than health controls. Other subgroup analyses were conducted by region, language, source of control, age, and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). In these subgroups, the sRANKL levels were significantly higher in the patients with AS than in healthy controls. The BASFI and BASDAI were sources of heterogeneity.

Conclusions

The sRANKL levels are higher in Chinese patients with AS, especially among those from South China. sRANKL levels may be positively correlated with the pathogenesis of AS among Chinese patients.

Spectrums and Prognosis of Kidney Disease in Patients with Ankylosing Spondylitis

Background/Aims

Renal involvement was a common extra-articular manifestation of ankylosing spondylitis (AS). Few reports have investigated the pathological characteristics and renal outcomes of AS patients with kidney disease. The aim of this study was to investigate the pathological spectrums and the renal prognosis of AS patients with kidney disease.

Methods

This retrospective and observational study was conducted working on 62 patients (47 males and 15 females) with a diagnosis of AS (ACR, 1984) and renal biopsies between 2008 and 2017. The histopathological findings and associated clinical manifestations were collected, and the renal prognoses of patients with kidney disease were evaluated too. Multivariate binary logistic regression analysis was performed to identify risk factors for the occurrence of IgA nephropathy (IgAN).

Results

Renal biopsy revealed that IgAN accounted for a majority (74.2%) of the kidney disease with AS, while membranous nephropathies, minimal change disease, focal segmental glomerulosclerosis, and other lesions accounted for a small minority. Multivariate analysis revealed that serum immunoglobulin A >3.45 g/L and immunoglobulin G >9.06 g/L were risk factors for the occurrence of IgAN. With a median follow-up time of 24.3 months, 28 patients (50.9%) reached complete remission, 9 patients (16.4%) had partial remission, and 1 patient had an eGFR decline >30%. No difference was found in prognosis between IgAN and non-IgAN.

Conclusion

IgAN occurred in 76.4% of the kidney disease with AS, and higher serum immunoglobulin A and G increased the risk for the occurrence of IgAN. The renal prognosis of kidney disease in AS was good.

HLA-B27 Negativity Is Associated With Renal Function Decline in Patients With Ankylosing Spondylitis and Secondary IgA Nephropathy

This study aimed to determine the impact of HLA-B27 on clinical phenotype and renal function during follow-up periods in patients with ankylosing spondylitis (AS) and secondary IgA nephropathy (IgAN). This single-center retrospective study included 71 AS patients with secondary IgAN. Renal function decline was defined as a mean eGFR decline of more than 5 mL/min/1.73 m² per year or progression into the dialysis stage. The association between HLA-B27 status and renal function decline was evaluated by univariable and multivariable Cox regression analyses. The results showed that seven (9.85%) of the 71 included patients were HLA-B27-negative. The median follow-up period was 4.0 years. HLA-B27-negative patients showed higher levels of uric acid (UA) than those who were HLA-B27-positive. Pathologically, a higher percentage of globally sclerotic glomeruli was observed in HLA-B27-negative patients. Survival analysis indicated that HLA-B27 negativity was associated with a significantly higher probability of renal function decline than HLA-B27 positivity. This significant association was also found in subgroup analyses of patients with either substantial proteinuria (more than 1.0 g per day) or interstitial fibrosis and tubular atrophy. Multivariable analysis showed that HLA-27 negativity was independently associated with renal function decline (HR 6.58; 95% CI 1.65 to 26.21; p = 0.008). In conclusion, HLA-B27 negativity is associated not only with a higher level of UA and a higher percentage of globally sclerotic glomeruli in AS patients with secondary IgAN but with renal function decline during follow-up periods.

Gender and chronic kidney disease in ankylosing spondylitis: a single-center retrospectively study

BACKGROUND

Ankylosing spondylitis (AS) is a well-known male-predominant inflammatory disease. This study aimed to assess the gender disparity in chronic kidney disease (CKD) in AS patients in China.

METHODS

AS patients were retrospectively studied at Peking Union Medical College hospital between January 2002 and June 2018.

RESULTS

Among 616 patients with AS, 154 (25.0%) patients had CKD (age, 41.8 ± 14.2 years; male:female, 3.2:1). Overall, 80 (13.0%) patients had only microscopic hematuria, 62 (10.1%) had proteinuria with or without hematuria, and 33 (5.4%) exhibited a reduced estimated glomerular filtration rate (eGFR, ≤60 mL/min/1.73 m²). Male CKD patients had more frequent proteinuria (p < 0.01), less microscopic hematuria only (p < 0.01), and lower eGFR (p = 0.04) compared with females. CKD was independently associated with hyperuricemia and total cholesterol in females, and with hyperuricemia, hypertension, and serum albumin in males. After follow-up for 1-7 years, five patients required renal replacement therapy including two patients who were already at stage 5 CKD when enrolled and three patients whose creatinine doubled. One patient died in the male group. No patients in the female group showed progression of renal dysfunction.

CONCLUSIONS

CKD is a common comorbidity in patients with AS. Male patients are more likely to develop severe manifestations compared with female patients. Hyperuricemia was a strong independent risk factor for CKD in both genders, while hypertension and low serum albumin were risk factors for CKD only in males.

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.

Comparison of secondary IgA nephropathy in patients with ankylosing spondylitis and rheumatoid arthritis

Objectives: The aim of the present study was to investigate the differences in clinic-pathological features of secondary IgA nephropathy (SIgAN) between patients with ankylosing spondylitis (AS) and rheumatoid arthritis (RA).Methods: Forty-six patients with SIgAN related to AS (SIgAN-AS) and 26 patients with SIgAN related to RA (SIgAN-RA) were enrolled in this retrospective study. The two groups were compared for their clinic-pathological characteristics.Results: The 10-year prevalence of SIgAN-AS and SIgAN-RA were 167 per 1000 and 51.3 per 1000, respectively. Compared with SIgAN-RA patients, SIgAN-AS patients had lower incidences of edema and nephrotic syndrome, but higher levels of eGFR, serum C3, and CD3- and CD8-positive T-cell counts, but less incidences of acute tubulointerstitial lesions and interlobular arterial lesions. IgM was the most familiar co-depositing immune complex on tissue with significantly different frequencies. In SIgAN-AS patients, those with positive HLA-B27 presented with lower levels of proteinuria, higher levels of serum IgG and C3, and less incidence of renal insufficiency, crescents >14.5%, glomerular sclerosis >32.6% and segmental sclerosis >5.2%.Conclusion: SIgAN was more prevalent in AS than in RA. SIgAN-AS patients differed from SIgAN-RA patients in certain clinic-pathological characteristics. HLA-B27 likely protected SIgAN-AS patients from renal insufficiency.