Renal diseases in ankylosing spondylitis: review of the literature illustrated by case reports

Rituximab as possible therapy in TNF inhibitor-induced IgA vasculitis with severe renal involvement

BACKGROUND

We observe the increasing use of tumor necrosis factor (TNF) inhibitors in patients affected by chronic inflammatory diseases. These drugs provide good control of symptoms, contributing to significant improvement in the quality of life in individuals with high disease burden. On the other hand, along with their wider use and longer follow-up periods the number of reports regarding their adverse effects is also increasing. The reported complications include drug-induced vasculitis with possible kidney involvement. In the literature we can distinguish more frequently described ANCA-associated vasculitis and more rarely occurring immunoglobulin A vasculitis. Although uncommon, such complications may present with potentially life-threatening vital organ dysfunction; therefore, adequate monitoring and effective therapy are necessary.

CASE PRESENTATION

We report two cases of TNF inhibitor-induced vasculitis with severe acute worsening of renal function and significant proteinuria. The first patient was receiving golimumab therapy for ankylosing spondylitis and the second patient was treated with adalimumab for psoriasis and psoriatic arthritis. In the second case dialysis treatment was necessary and the patient presented recurrence of vasculitis after rechallenge with adalimumab. Both patients underwent renal biopsy which showed findings compatible with drug-induced IgA vasculitis and both were treated successfully with corticosteroids and rituximab.

CONCLUSIONS

To the best of our knowledge this is the first report of rituximab use in drug-induced IgA vasculitis with renal involvement. Combination of corticosteroids and rituximab can be an effective therapy in case of vasculitis with kidney failure and a preferable option for selected patients with drug-induced IgA vasculitis compared to cyclophosphamide. More studies are necessary to establish suitable short- and long-term treatment. Given the rarity of this disorder, case reports and case series can provide practical guidance until additional studies become available.

Increased risk of stroke among patients with ankylosing spondylitis: A systematic review and meta-analysis

BACKGROUND

Ankylosing spondylitis is a chronic inflammatory disease that is associated with adverse cardiovascular events. This study aimed to determine the relationship between ankylosing spondylitis and the risk of stroke.

METHODS

A systematic literature search in PubMed/MEDLINE, Scopus, and Web of Science were conducted from inception to December 2021 to identify relevant articles investigating the risk of stroke in patients with ankylosing spondylitis. A random-effects model (DerSimonian and Laird) was used to estimate a pooled hazard ratio (HR) and 95% confidence intervals (CI). Meta-regression based on the length of follow-up and subgroup analysis based on the type of stroke, study location, and year of publication to investigate the source of heterogeneity.

RESULTS

A total of eleven studies comprising 1.7 million participants were included in this study. Pooled analysis showed a significantly increased stroke risk (56%) among patients with ankylosing spondylitis (HR: 1.56, 95% CI 1.33-1.79). Subgroup analysis revealed a higher risk of ischemic stroke among patients with ankylosing spondylitis (HR: 1.46, 95% CI: 1.23-1.68). However, meta-regression analysis showed no association between the duration of ankylosing spondylitis and stroke incidence (Coef=-0.0010, P=0.951).

CONCLUSION

This study reveals that ankylosing spondylitis was associated with an increased risk of suffering a stroke. Management of cerebrovascular risk factors and the control of systemic inflammation should be considered in patients with ankylosing spondylitis.

[Renal manifestations in rheumatoid arthritis and spondylarthritis]

As systemic diseases it is not uncommon for inflammatory rheumatic diseases to exhibit renal involvement. In contrast to connective tissue diseases and vasculitis, in rheumatoid arthritis and spondylarthritis direct inflammatory manifestations in the sense of glomerulonephritis (GN) and autoimmune interstitial nephritis are rare. In these groups of diseases renal biopsies usually show mesangial proliferative GN and IgA nephropathy or less commonly membranous GN. These and secondary amyloid A (AA) amyloidosis are regularly associated with longer lasting disease activity and a poor prognosis; however, clinically more frequent and more relevant are other sequelae of chronic systemic inflammation, namely endothelial function disorder and the premature development of atherosclerosis, resulting in progressive kidney failure. This is accompanied by the undesired effects of antirheumatic treatment and renal complications of comorbidities.

The effect of anti-TNF on renal function in patients with ankylosing spondylitis: a prospective cohort study

BACKGROUND

Biologicals, such as anti-tumor necrosis factor (anti-TNF), reduce cardiovascular disease (CVD) in patients with inflammatory rheumatic diseases. Impaired renal function is a known predictor of CVD and elevated in ankylosing spondylitis (AS).

OBJECTIVE

To assess the effect of anti-TNF on renal function in patients with AS and whether anti-TNF use is safe in AS patients with pre-existing risk factors for renal decline.

METHOD

Biological-naïve consecutive AS patients treated with etanercept or adalimumab were prospectively followed from 2005 to 2014. Renal function was determined by calculation of the estimated glomerular filtration rate (eGFR), estimated with the abbreviated modification of diet in renal disease (MDRD) formula. The effect of anti-TNF on eGFR was analyzed using mixed model analysis.

RESULTS

211 AS patients were followed for a median of 156 (36-286) weeks. Overall mixed model analyses showed a significant decrease of eGFR over time (β =  - 0.040, p = 0.000), although this association did not remain significant after adjustment for responding to anti-TNF, alcohol use, disease duration, body mass index (BMI), C-reactive protein (CRP), and disease activity (β =  - 0.018, p = 0.094). However, patients with pre-existing risk factors for renal decline did have a significant change in eGFR over time (β =  - 0.029, p = 0.006).

CONCLUSIONS

We found a significant change in eGFR over time, although this small decrease was not clinically relevant. This study further demonstrates that anti-TNF does not affect renal function in AS patients with and without existing risk factors for renal decline, which means that use of anti-TNF is safe concerning renal function in patients with AS. Key Points • Previous studies showed that biologicals, such as anti-tumor necrosis factor (anti-TNF), reduce cardiovascular disease (CVD) in patients with inflammatory rheumatic diseases, such as ankylosing spondylitis (AS). • Impaired renal function is a known predictor of CVD, and also a known concern for many AS patients. • Use of anti-TNF is safe with regard to renal function in patients with AS. • The effect of anti-TNF on CVD in AS patients does not seem to be mediated by changes in renal function.

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.

Glomerulonephritis in Two Patients with SpA Treated with TNF-α Blockers and a Review of the Literature

Renal failure or acute/chronic kidney damage may present as a clinical manifestation of rheumatic diseases. In addition treatment with DMARDs or biologic drugs may induce nephrotoxicity. In this case-based review, we present two patients with SpA under anti-TNF-α treatment admitted to our hospital because of renal failure and proteinuria. We review previously published yet isolated cases of TNF-α blocker-induced glomerular disease in patients with SpA. Renal manifestations are occasionally seen in patients with ankylosing spondylitis and psoriatic arthritis with IgA nephropathy being the most common of them. Anti-TNF-α agents although reportedly used for the treatment of glomerular nephropathy as a disease manifestation, they have been considered responsible for provoking renal damage in some cases. A diagnostic approach for patients with SpA treated with anti-TNF-α agents presenting with renal manifestations is proposed herein.

Onset of IgA nephropathy in a patient treated with infliximab for ankylosing spondylitis

We report the case of a 43-year-old man, suffering from ankylosing spondylitis and treated with Infliximab 5 mg/kg every 2 months, with an excellent disease control. During a follow-up consultation, an incipient renal insufficiency is detected. A urine analysis showed haematuria and proteinuria and a renal puncture-biopsy revealed an image of IgA nephropathy.Several cases of IgA nephropathy have been reported in the literature associated with ankylosing spondylitis. Some of them occur in patients treated with antitumour necrosis factor, but it is unclear whether this pathology is caused by the treatment or whether treatment failed to prevent its occurrence.Our clinical case highlights the importance of regular monitoring of renal function in patients with ankylosing spondylitis, as well as urinary spotting.The question of whether the disease itself, the treatment or other factors such as immune dysregulation could be held responsible for kidney disease will be addressed in the discussion.

Secondary Membranous Nephropathy. A Narrative Review

Membranous nephropathy (MN) is a common cause of proteinuria and nephrotic syndrome all over the world. It can be subdivided into primary and secondary forms. Primary form is an autoimmune disease clinically characterized by nephrotic syndrome and slow progression. It accounts for ~70% cases of MN. In the remaining cases MN may be secondary to well-defined causes, including infections, drugs, cancer, or autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), urticarial vasculitis, sarcoidosis, thyroiditis, Sjogren syndrome, systemic sclerosis, or ankylosing spondylitis. The clinical presentation is similar in primary and secondary MN. However, the outcome may be different, being often related to that of the original disease in secondary MN. Also, the treatment may be different, being targeted to the etiologic cause in secondary MN. Thus, the differential diagnosis between primary and secondary MN is critical and should be based not only on history and clinical features of the patient but also on immunofluorescence and electron microscopy analysis of renal biopsy as well as on the research of circulating antibodies. The identification of the pathologic events underlying a secondary MN is of paramount importance, since the eradication of the etiologic factors may be followed by remission or definitive cure of MN. In this review we report the main diseases and drugs responsible of secondary MN, the outcome and the pathogenesis of renal disease in different settings and the possible treatments.

Membranous nephropathy and thymoma in a patient with ankylosing spondylitis: A case report

RATIONALE

We report a rare case with ankylosing spondylitis (AS), thymoma, and membranous glomerulonephritis. The pathogenic mechanisms of these 3 diseases may be associated with each other. Here, we discuss the course of diagnosis and treatment.

PATIENT CONCERNS

A 64-year-old woman with bilateral pain of the sacroiliac joints for 10 years and anasarca for 10 days.

DIAGNOSES

A diagnosis of AS by HLA-B27 and pelvic X-ray tests, thymoma based on computed tomography and pathological diagnosis, and membranous glomerulonephritis based on renal biopsy.

INTERVENTIONS

We administered methylprednisolone 500 mg/d for 3 consecutive days, followed by methylprednisolone 40 mg oral QD, for a month.

OUTCOMES

The patient was followed up once a month. In the sixth month, the patient's serum creatinine had decreased to 0.96 mg/dL, urine microalbumin/creatinine decreased to 173.3 mg/g, and albumin had risen to 33.1 g/L. Pain and morning stiffness were relieved, and the Bath Ankylosing Spondylitis Disease Activity Index score dropped to 4.0.

LESSONS

Although the causal relationship between AS, thymoma, and membranous nephropathy in this patient still needs to be established, the pathogenesis between the 3 diseases may have some association. In clinical practice, patients with AS need to be screened for tumors and renal complications.

Spondyloarthritis-Associated IgA Nephropathy

Introduction

IgA nephropathy (IgAN) can be associated with spondyloarthritis (SpA). The course of SpA-associated IgAN remains largely unknown due to the absence of large cohorts.

Methods

This retrospective study included patients with biopsy-proven IgAN and definite SpA. Kidney biopsies were centrally examined and scored according to the IgAN Oxford Classification. Thirty-two patients fulfilled the inclusion criteria, with a male:female ratio of 9:1 and median age of 27 and 37 years at SpA and IgAN diagnosis, respectively. HLA-B27 was positive in 90% of cases, and most patients (60%) presented with ankylosing spondylitis. The mean baseline estimated glomerular filtration rate (eGFR) was 84 ± 26 ml/min per 1.73 m², and the urine protein-to-creatinine ratio was 0.19 g/mmol.

Results

Renal biopsy revealed frequent presence of crescents (33%) and interstitial inflammation (18%). Despite almost constant use of renin-angiotensin system inhibitors, combined with steroids in 13 of 32 patients, renal outcome was particularly poor. After a median follow-up of 5.9 years, 4 patients (12.5%) reached end-stage renal disease and 41% of patients experienced a >50% decrease of eGFR. The mean annual eGFR decline rate was -4.3 ± 6.7 ml/min per 1.73 m². The risk of reaching class IV or V chronic kidney disease (CKD) stage during follow-up was associated with the presence of hypertension, level of proteinuria, and baseline S- and T-scores of the Oxford.

Conclusion

SpA-associated IgAN is associated with a poor renal outcome, despite frequent use of steroids. Tumor necrosis factor (TNF)-α blockade did not appear to influence the rate of eGFR decline in this setting.

Infliximab-associated focal segmental glomerulosclerosis in a patient with ankylosing spondylitis

The introduction of tumor necrosis factor-alpha (TNF-α)-targeting drugs has given new opportunities in the treatment of various inflammatory rheumatic diseases and has been the most important development in the treatment of spondyloarthritis (SpA). However, the increasing use and longer follow-up periods of treatment also pose risks of developing various adverse effects ranging from common ones including infections to uncommon renal complications. This report describes a case of infliximab-induced focal segmental glomerulosclerosis (FSGS) in a 40-year-old female patient with ankylosing spondylitis (AS) who presented with asymptomatic proteinuria and microscopic hematuria. To the best of our knowledge, this is the second reported case of FSGS attributed to infliximab (IFX). A review of the English literature was conducted for cases of possible IFX-associated renal disorders in patients with SpA and SpA spectrum diseases. In this respect, the reported renal pathologies were IgA nephropathy, crescentic glomerulonephritis, acute renal artery occlusion, acute tubulointerstitial nephritis (ATIN), FSGS, and membranous glomerulopathy. Furthermore, partial or complete resolution was reported after cessation of therapy. In conclusion, although renal complications of TNF inhibitors (TNFi) are uncommon, spot urine evaluation may be recommended in the follow-up of patients treated with TNFi.

The prevalence of comorbidity and predictors in ankylosing spondylitis

Objectives

The aim of the present study was to investigate the prevalence of comorbidities and related factors in patients with ankylosing spondylitis (AS).

Patients and methods

Between June 2013 and January 2014, a total of 100 patients with AS (64 males, 36 females; mean age 43.1±10.7 years; range, 25 to 73 years) who were under routine follow-up in the outpatient clinic were included in this cross-sectional study. The demographic characteristics of the patients were recorded. The Ankylosing Spondylitis Disease Activity Scale (ASDAS), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), and Bath Ankylosing Spondylitis Metrology Index (BASMI) scores were calculated. Comorbidities were evaluated using the modified Cumulative Illness Rating Scale (CIRS). Both the number and severity of the affected systems were scored.

Results

The mean amount of cigarette consumption was 17.3±13.5 pack/year. The mean disease duration was 191.3±122.4 months. The BASFI, BASDAI, BASMI, and ASDAS-C-reactive protein scores were 3.4±2.3, 3.7±2.0, 4.5±1.8, and 2.5±0.9, respectively. The mean number of system-related problems was 4.3 (range, 1 to 11). The mean CIRS scores for the severity of comorbidities were 7.36±3.48 (range, 3 to 23). The most frequent system combinations were hematopoietic, eye, ear, nose and throat, and upper gastrointestinal in 11 patients, hematopoietic, respiratory and upper gastrointestinal in 11 patients, and hematopoietic, respiratory and eye, ear, nose and throat in 10 patients. When the estimated total CIRS scores was assessed in the multivariate reduced model, age, disease duration, and BASFI values showed a significant independent effect.

Conclusion

Our study results showed that the frequency of comorbidities was more than four, although the severity of system problems were mild in AS patients as measured by CIRS. The most frequently involved systems included hematopoietic, upper gastrointestinal, lower gastrointestinal, renal, and musculoskeletal-skin systems. Age, disease duration, and BASFI scores were found to be predictors of comorbidities in our patients.

Gender Is a Risk Factor for Annual Decline in Estimated Glomerular Filtration Rate in Patients Treated with Biological DMARDs in Rheumatoid Arthritis and Ankylosing Spondylitis: a Retrospective Observational Study

BACKGROUND

This study identified the risk factors of changes in renal function in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS) treated with biological disease-modifying anti-rheumatic drugs (bDMARDs).

METHODS

We retrospectively enrolled patients with RA (n = 293) and AS (n = 125) treated with bDMARDs. The estimated glomerular filter rate (eGFR) using the Modification of Diet in Renal Disease equation was applied for assessment of annual changes in renal function between initiation and last visit after bDMARD therapy. The annual change in eGFR was used as an indicator for change in renal function. Statistical significance was assessed by Mann-Whitney test, Spearman's correlation coefficient, and multivariate linear regression analysis.

RESULTS

The positive annual change in eGFR in women was significantly noted, compared to that in men (P = 0.004). The annual change in eGFR was different between men and women (P = 0.038) in RA, but not in AS patients (P = 0.126). In multivariate linear regression analysis, women patients and increased serum creatinine at baseline were closely associated with positive annual change in eGFR in both RA and AS patients. In RA patients, younger age and lower ESR level were considered risk factors of positive annual change in eGFR (P = 0.013 and P = 0.022, respectively). However, disease duration and duration of bDMARD use were not associated with annual change in eGFR.

CONCLUSION

This study found that gender, especially men, might be responsible for annual decline in eGFR in RA and AS patients treated with bDMARDs.

Axial Spondyloarthritis and Autosomal Dominant Polycystic Kidney Disease in Two Siblings: A Rare Cooccurrence

Autosomal dominant polycystic kidney disease (ADPKD) is the most frequently occurring hereditary kidney disease, and axial spondyloarthritis (SpA) is one of the most frequently occurring rheumatic diseases. Treatment-related decisions for axial SpA may pose a challenge in case of renal involvement. The authors describe two siblings with cooccurrence of these two diseases. The association of these two diseases is not well known. Practitioners should monitor renal function in SpA patients and take treatment-related decisions regarding renal involvement. Antitumor necrosis factor-alpha (anti-TNF-α) agents may be used in case nonsteroidal anti-inflammatory drugs (NSAIDs) cannot be utilized.

[IgA nephropathy: Unusual forms]

IgA nephropathy can have various initial presentation and evolutive characteristics. In this article, specific forms of IgA nephropathy are described, such as hypertensive emergency, nephrotic syndrome, rapidly progressive glomerulonephritis, monotypic IgA deposits, or IgA nephropathy associated with inflammatory diseases. Identification of these specific forms is needed to better characterize and treat these rare pathologies.

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

BACKGROUND/AIMS

Renal involvement is one of the most common extra-articular complications caused by ankylosing spondylitis (AS). Most studies have focused on the incidence rate, clinical manifestation and pathology, while risk factors have hardly been investigated. Therefore, the objective of this study was to assess the risk factors of renal involvement in patients with AS.

METHODS

Clinical and biochemical data of 926 AS patients were collected. Based on the manifestations of renal involvement, patients were divided into three groups and the differences in clinical and biochemical characteristics were compared. A group with non-renal involvement served as a control. Multivariable logistic regression was used for analyzing risk factors of renal involvement in AS.

RESULTS

Of the 926 AS patients, 201 patients suffered from renal involvement. Moreover, female AS patients faced a higher risk of hematuria compared to male patients. As indicated by the data obtained from multivariate logistic regression analysis, gender, uric acid (UA), immunoglobulin A (IgA), and serum albumin (ALB) were found to be risk factors of renal involvement in AS. An increase in UA or IgA levels, or a decrease in ALB level can increase the risk of renal involvement with multiple manifestations (more than one manifestation of renal damage). According to our findings, no definite variable was identified as a risk factor of proteinuria in AS patients.

CONCLUSION

In AS patients, UA, IgA, and ALB levels can indicate the risk of renal involvement in AS patient and need to be paid special attention. Furthermore, women are subjected to a higher risk of hematuria.

Membranous nephropathy in a patient with ankylosing spondylitis: A case report

RATIONALE

Renal complications in ankylosing spondylitis (AS) were rarely observed, and proteinuria associated with AS can be seen often due to amyloidosis in this kind of complications, while membranous nephropathy (MN) is seldom considered. This article reports a case of coexistence of AS and MN, to provide the exact relationship of these 2 entities and recognized some causes of renal involvement in AS.

PATIENT CONCERNS

A 44-year-old female presented with pain of the left leg for 4 years and pedal edema for 2 weeks.

DIAGNOSES

AS was diagnosed according to the patient's clinical manifestation and sacroiliitis observed on computed tomography (CT) scan. Nephrotic syndrome was found and MN was diagnosed according to kidney biopsy in which thickened capillary loops were observed with light microscopy, granular deposits of IgG along the capillary wall were observed using immunofluorescence staining, and subepithelial electron-dense deposits were observed with electron microscopy. No other secondary causes of MN were found on extensive investigations.

INTERVENTION

Given the diagnoses, the patient received nonimmunosuppressive therapy for MN and adalimumab for AS.

OUTCOMES

The patient got pain relief, as well as urinary protein reduction.

LESSONS

This case suggested a secondary MN in association with AS and the relationship between these 2 diseases needed more concern and further illumination.

Prevalence of comorbidities and evaluation of their screening in spondyloarthritis: results of the international cross-sectional ASAS-COMOSPA study

BACKGROUND

Increased risk of some comorbidities has been reported in spondyloarthritis (SpA). Recommendations for detection/management of some of these comorbidities have been proposed, and it is known that a gap exists between these and their implementation in practice.

OBJECTIVE

To evaluate (1) the prevalence of comorbidities and risk factors in different countries worldwide, (2) the gap between available recommendations and daily practice for management of these comorbidities and (3) the prevalence of previously unknown risk factors detected as a result of the present initiative.

METHODS

Cross-sectional international study with 22 participating countries (from four continents), including 3984 patients with SpA according to the rheumatologist.

STATISTICAL ANALYSIS

The prevalence of comorbidities (cardiovascular, infection, cancer, osteoporosis and gastrointestinal) and risk factors; percentage of patients optimally monitored for comorbidities according to available recommendations and percentage of patients for whom a risk factor was detected due to this study.

RESULTS

The most frequent comorbidities were osteoporosis (13%) and gastroduodenal ulcer (11%). The most frequent risk factors were hypertension (34%), smoking (29%) and hypercholesterolaemia (27%). Substantial intercountry variability was observed for screening of comorbidities (eg, for LDL cholesterol measurement: from 8% (Taiwan) to 98% (Germany)). Systematic evaluation (eg, blood pressure (BP), cholesterol) during this study unveiled previously unknown risk factors (eg, elevated BP (14%)), emphasising the suboptimal monitoring of comorbidities.

CONCLUSIONS

A high prevalence of comorbidities in SpA has been shown. Rigorous application of systematic evaluation of comorbidities may permit earlier detection, which may ultimately result in an improved outcome of patients with SpA.

[Prognosis and therapy of inflammatory rheumatic diseases : Impact of renal manifestations]

BACKGROUND

Inflammatory rheumatic diseases and their treatment cause various renal manifestations requiring modification of treatment.

OBJECTIVES

Discussion of renal manifestations in selected rheumatic diseases, including their impact on general prognosis and therapy.

MATERIALS AND METHODS

Basic literature and expert opinions are analyzed and discussed.

RESULTS

Inflammatory rheumatic diseases and their treatment cause various renal manifestations, including glomerular, tubular, interstitial, and vascular damage. The type of damage determines both, associated clinical symptoms (i.e. hematuria, proteinuria, loss of kidney function) and the renal and overall survival as will be discussed here for rheumatoid arthritis, systemic lupus erythematosus, scleroderma, Sjögrens syndrome, cryoglobulinemia and ANCA-associated vasculitis.

CONCLUSION

Renal manifestations are generally indicators of high disease activity and usually require more intensive treatment of the underlying rheumatic disease. Early and rigorous treatment, which has to be adapted to renal function, is capable of improving renal and overall survival in many of the affected patients.

Pulmonary, renal and neurological comorbidities in patients with ankylosing spondylitis; implications for clinical practice

Ankylosing spondylitis (AS) is associated with several comorbidities which contribute significantly to morbidity and mortality and add to the complexity of management. In addition to the well known extra-articular manifestations and increased cardiovascular risk, several pulmonary, renal, and neurological complications which have been associated with AS deserve equal attention. Whereas a clear link has been established for some manifestations, the evidence for other associations is less clear. Interstitial lung disease, apical fibrosis, secondary infection, and ventilatory restriction from reduced chest wall movement are well known pulmonary complications; more recently an association with sleep apnoea has been suggested. Renal amyloidosis and IgA nephropathy remain a treatment challenge which may respond to anti-TNF therapy. Atlanto axial subluxation and vertebral fractures can result in serious neurological complications and are notoriously difficult to diagnose unless a high level of suspicion is maintained. Despite several reports linking AS with demyelination a true link remains to be proved. This review discusses the prevalence, pathophysiology, and management of pulmonary, renal, and neurological complications, and implications for clinical practice.

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.

Etanercept-induced Henoch-Schönlein purpura in a patient with ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory disease that primarily affects the axial skeleton. Extra-articular manifestations are less common relative to other rheumatic diseases, and vasculitic complications typically involve the ascending aorta and aortic valve. The use of tumor necrosis factor inhibitors is efficacious in the treatment of patients with AS. Since their routine use, however, tumor necrosis factor inhibitors have been associated with the development of drug-induced complications including the induction of lupus and both cutaneous and systemic vasculitis. In this report, we describe a patient with severe longstanding AS, who developed Henoch-Schönlein purpura after commencing therapy with etanercept. Tumor necrosis factor inhibitor-induced Henoch-Schönlein purpura has been very rarely reported and has been mostly recognized in patients with rheumatoid arthritis.

Secondary amyloidosis in ankylosing spondylitis

We evaluated the frequency of secondary amyloidosis, associated clinical features, and outcomes in ankylosing spondylitis (AS) patients diagnosed in the last decade. The medical records of AS patients diagnosed at single academic medical center were reviewed for clinical evidence of amyloidosis. During routine follow-up, routine urinalysis was performed at each visit; patients with significant proteinuria underwent rectal biopsy. We diagnosed 8 clinically apparent amyloidosis patients (1.1 %) in our cohort of 730 AS patients (508 males, 222 females). Four patients undergoing hemodialysis were diagnosed secondary amyloidosis. Three patients had nephrotic syndrome and renal dysfunction and one patient had non-nephrotic proteinuria. When AS patients with amyloidosis were compared to AS controls, it was observed that the amyloidosis group was older, had longer disease duration, higher initial BASDAI scores, and ESR values, and more frequent peripheral arthritis (p < 0.05). Logistic regression analysis revealed that the initial BASDAI level was an independent predictor for the development of secondary amyloidosis (OR:2.36). Six patients were administered anti-TNF therapy. The clinical findings resolved in these. In 2 patients with nephrotic syndrome and renal dysfunction, in addition to clinical improvement, there was a decrement in proteinuria; renal function improved or remained stable. Anti-TNF therapy is safe and effective in patients with renal failure, and at an earlier stage, appears effective in improving renal function. The development of proteinuria in AS patients should occasion a search for underlying amyloidosis.

Renal involvement in ankylosing spondylitis: prevalence, pathology, response to TNF-a blocker

Ankylosing spondylitis (AS) is a chronic inflammatory disease primarily involving the spine and sacroiliac joint and rarely the kidneys. This study aimed to define the clinical and histological features and biology of renal disease in AS. We reviewed the medical records of 681 patients diagnosed with AS from November 2008 to November 2009. Baseline characteristics and laboratory and urinalysis results were reviewed. We identified patients with proteinuria or hematuria and analyzed their risk factors. After providing informed consent, 6 patients underwent a renal biopsy to determine the cause of proteinuria or hematuria. Of the 681 enrolled patients, 547 were men and 134 were women; 81 % were HLA B27 positive, and 8 % had abnormal urinalysis findings (proteinuria, 5.9 %; hematuria, 2.8 %; both, 0.7 %). Incidences of peripheral arthritis and uveitis were 29 % and 18.6 %, respectively. Immunoglobulin (Ig)A and uric acid levels were significantly different between patients with and without proteinuria. Erythrocyte sedimentation rate (ESR), total cholesterol, creatinine, and C-reactive protein (CRP) levels were not statistically significantly different between the 2 groups nor were there any significant differences in IgA, uric acid, ESR, total cholesterol, creatinine, and CRP levels between patients with and without hematuria. Six patients who had >1 g/day proteinuria underwent a renal biopsy; 2 were diagnosed with IgA nephropathy, 1 with amyloidosis, and 3 with non-specific glomerulonephropathy. In the amyloidosis patient, severe proteinuria was the dominant feature. For patients with renal amyloidosis and other forms of glomerulonephritis who initially had normal creatinine levels, tumor necrosis factor (TNF)-alpha blocker therapy resolved proteinuria, but this was not the case for patients with initial renal insufficiency. Renal involvement is not a rare complication of AS, and prognoses differ depending on kidney pathology. Serum levels of uric acid and IgA may predict renal involvement in AS. In cases where abnormal urine sediment is identified, renal biopsy is required to determine prognosis and decide the treatment protocol. Baseline serum creatinine level is important for predicting treatment response.

Mortality in spondylarthritis

Ankylosing spondylitis (AS) is a chronic inflammatory joint disease that can lead to chronic pain in axial and peripheral joints and to functional impairments after several years. Excess mortality has been reported in patients with AS. We reviewed recent studies of patients with AS who were treated and monitored according to the improved methods developed in the past few years, without radiation therapy. Our results do not support excess mortality in these patients. Long-term follow-up data from patients enrolled in biologics registries will provide additional information. Cardiovascular disease is the leading cause of death in patients with AS, as in the general population. However, the cardiovascular mortality rate may be slightly increased in patients with AS, probably as a result of dyslipidemia and early endothelial dysfunction. Similarly, and as expected, there is excess mortality related to the spinal disease itself and to renal and gastrointestinal disease. More surprisingly, alcohol abuse and injury or suicide cause excess mortality compared to the general population. In the absence of radiation or radium-224 therapy, and regardless of the other treatments used, the evidence does not support an increased rate of lymphoma or other malignancies compared to the general population. In this review, we discuss the causes and rates of mortality in patients with AS.

Systemic amyloidosis: a challenge for the rheumatologist

Amyloidosis comprises a group of diseases characterized by the extracellular deposition of insoluble fibrillar proteins. This mechanism generates different clinical syndromes depending on the site and extent of organ involvement. Amyloidosis is classified into categories of systemic and localized disease. Systemic amyloidosis is further subdivided into a hereditary familial form (for example, ATTR amyloidosis), a reactive form (AA amyloidosis), dialysis-related (Abeta(2)M) amyloidosis and immunoglobulin light chain (AL) amyloidosis. Treatment can be symptomatic, directed at the affected organ, or can be directed at reducing the production of the abnormal proteins with different strategies. Despite advances in treatment, the prognosis is still poor and depends on the underlying disease as well as the type and degree of dysfunction in involved organs. Early diagnosis is essential because patients with advanced disease are generally unable to undergo intensive therapy. Patients with systemic amyloidosis often present to a rheumatologist not only because the disease can include musculoskeletal and articular symptoms but also because it can be associated with chronic rheumatic diseases. This Review discusses the clinical features of amyloidosis and its rheumatic manifestations. The various types of amyloidosis, as well their prognosis and treatment, are also presented.

IgA nephropathy associated with ankylosing spondylitis is not controlled by infliximab therapy

The association between seronegative spondyloarthro- pathies and IgA nephropathy is well documented, mainly in cases of ankylosing spondylitis (AS). However, although these diseases have been associated, the physiopathological links between each other appear unclear. Anti-TNFalpha agents have transformed the outcome of axial forms of AS resistant to conventional anti-inflammatory therapies. Infliximab, a monoclonal anti-TNFalpha antibody, has greatly improved the evolution of AS although several adverse events have been described. On the other hand, infliximab has been demonstrated to reduce renal symptoms associated with chronic inflammatory rheumatological diseases, such as amyloid A (AA) amyloidosis, but few data are available on its efficacy in controlling IgA nephropathy associated with AS [1,2]. We report here a case of IgA nephropathy associated with AS that became symptomatic, whereas infliximab therapy efficiently controlled the rheumatological disease. This suggests that even though infliximab therapy effectively controls rheumatological manifestations, it may not be able to prevent IgA nephropathy associated with AS. Thus, this case report illustrates the complexity of the physiopathology of both diseases.

Ankylosing spondylitis and spinal cord injury: origin, incidence, management, and avoidance

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease that primarily affects the vertebral column and sacroiliac joints. Over time, the disease process promotes extensive remodeling of the spinal axis via ligamentous ossification, vertebral joint fusion, osteoporosis, and kyphosis. These pathological changes result in a weakened vertebral column with increased susceptibility to fractures and spinal cord injury (SCI). Spinal cord injury is often exacerbated by the highly unstable nature of vertebral column fractures in AS. A high incidence of missed fractures in the ankylosed spine as well as an increased incidence of spinal epidural hematoma also worsens the severity of SCI. Spinal cord injury in AS is a complex problem associated with high morbidity and mortality rates, which can be attributed to the severity of the injury, associated medical comorbidities, and the advanced age of most patients with AS who suffer an SCI. In this paper the authors outline the factors that increase the incidence of vertebral column fractures and SCI in AS and discuss the management of SCI in patients with AS. Primary prevention strategies for SCI in patients with AS are outlined as well.

[Renal manifestations in rheumatic diseases]

Inflammatory rheumatic diseases other than systemic vasculitides and systemic lupus erythematosus are frequently associated with renal abnormalities, which are clinically less apparent due to the subtle course and the often only moderate impairment of renal function. These abnormalities include vascular, glomerular and tubulointerstitial changes. Renal manifestations in the course of rheumatoid arthritis influence the prognosis of the disease. Renal involvement due to AA amyloidosis following long-standing inflammatory joint disease can lead slowly, over years, to end-stage renal disease. A scleroderma renal crisis in the course of systemic sclerosis can potentially result in end-stage renal disease within days. The differential diagnosis of renal abnormalities in a rheumatic patient should include drug induced renal impairment as well as infection.

Ankylosing Spondylitis: A Contemporary Perspective on Diagnosis and Treatment

OBJECTIVES

In recent years, great progress has been made in the development of diagnostic tools, therapeutic approaches, and validated outcome measures in the understanding of the pathogenesis of ankylosing spondylitis (AS). The purpose of this review was to summarize these developments.

METHODS

We performed a PubMed search for the period 1978 to 2005, using the keyword, "ankylosing spondylitis," resulting in a total of 4878 publications, including 778 reviews. Articles were then selected based on their discussion of recent diagnostic tools and new treatment approaches in the pathogenesis of AS, leading to a final total of 104 articles.

RESULTS

In recent years, there have been 2 major developments in the management of AS that make earlier diagnosis possible and offer the hope of alleviating pain and preventing structural changes that result in loss of function. These developments include the use of magnetic resonance imaging to visualize the inflammatory changes in the sacroiliac joint and the axial spine, and the demonstration that tumor necrosis factor blocking agents are highly efficacious in reducing spinal inflammation and possibly in slowing radiographic progression.

CONCLUSIONS

There have been major advances in both the diagnostic tools and the therapeutic regimens available for patients with AS.

Bone and stone in ankylosing spondylitis: osteoporosis and urolithiasis

Ankylosing spondylitis (AS) has well-defined renal complications, but urolithiasis has not been studied in detail. We aimed to evaluate the relation between AS and urolithiasis presence and the effect of this coexistence on the bone mineral status of patients. By dual-energy x-ray absorptiometry measurements at the femoral neck and lumbar vertebrae, we assessed the influence of urolithiasis, disease activity, and duration on bone mineral density (BMD) at different sites. Fifty-three AS patients and 25 control subjects were enrolled in the study. Mean age was 39.49+/-13.01 years for the AS group and 43.80+/-10.69 years for the control group, with no statistically significant difference. Patients were accepted as having active disease if two of the following were present: (1) symptomatic peripheral arthritis, (2) erythrocyte sedimentation rate greater than 30 mm/h, (3) C-reactive protein greater than 5 mg/L, and (4) dorsal-lumbar morning stiffness more than 60 min. The ratios of urinary stone presence were 11.32 and 12% for AS and control groups, respectively. We observed that a statistically significant difference in femur neck BMD between AS patients with or without urolithiasis was apparent. The lumbar BMD values were also lower in the urolithiasis subgroup but could not reach the statistical significance. There were no significant BMD alterations in the control group due to stone presence. Comparison of active-inactive disease groups revealed significantly low T scores in either the femur neck or L2-4 regions of patients with higher activity indices, but this difference was more prominent in the femur neck. In the early AS group (23 patients), 18 patients (78.26%) had L2-4 T scores lower than -1 SD, and in the advanced AS population, 19 of 30 patients (63.33%) had either osteopenia or osteoporosis (OP). We conclude that severe disease and concomitant urolithiasis might increase bone loss and fracture risk especially at the femur neck.

Les manifestations rénales de la spondylarthrite ankylosante : à propos de 210 cas

PURPOSE

To define the epidemiology, clinical, biological and histological features of renal diseases in ankylosing spondylitis, ginving special attention to unusual forms.

METHODS

We retrospectively reviewed the medical record of 28 cases with renal involvement among 210 cases of ankylosing spondylitis seen over a 27 year period who met the Amor criteria.

RESULTS

Twenty-eight of 210 patients (13,3%) presented one or more signs of renal involvement: macroscopic hematuria (4 patients), microscopic hematuria (8 patients), proteinuria (15 patients), nephrotic syndrome (6 patients), decreased renal function (13 patients). Secondary renal amyloidosis and nephrolithiasis (8 patients) were the most common cause of renal involvement in ankylosing spondylitis followed by IgA nephropathy (3 patients).

CONCLUSION

The funding of renal abnormalities in 13,3% of our patients suggests that in this illness evidence of renal involvement should be actively investigated in ankylosing spondylitis.

[Extra-articular manifestations and complications of ankylosing spondylitis]

Extra-articular manifestations can be defined as all symptoms and signs etiopathogenically related, at least in part, to ankylosing spondylitis (AS) that arise in the various organs and tissues of the locomotor apparatus. Thus, ocular, intestinal and cardiac manifestations, which are common to all spondylarthritides through their association with HLA-B27, are grouped under this heading. Complications include clinical manifestations that result from persistent spondylitic activity and/or treatment. Table 1 provides a list and the main characteristics of these manifestations. Obviously, this classification is far from perfect since, among other factors, knowledge of the etiopathogenesis of AS is still fairly limited.

Renale Manifestationen rheumatischer Erkrankungen

Inflammatory rheumatic diseases are frequently complicated by subclinical or overt renal manifestations. This is well known for the connective tissue diseases and vasculitides in which renal disease can be of significant prognostic value and therapeutic implication. However, rheumatoid arthritis and the spondyloarthritides can also be associated with direct renal manifestation or with secondary renal AA-amyloidosis. The clinician should be aware of the different glomerular (i. e. nephritic or nephritic syndrome, rapidly progressive renal disease) and tubulo-interstitial syndromes. In any case of renal dysfunction in a rheumatic patient, the differential diagnosis should include renal disease independent from the rheumatic condition, infection, and drug-induced renal toxicity.

Clinical aspects, outcome assessment, and management of ankylosing spondylitis and postenteric reactive arthritis

The cause of ankylosing spondylitis remains unclear. Proof that this disorder is an autoimmune disease attributable to crossreactivity between bacteria and HLA-B27 is still lacking. Differences in endogenous peptide presentation by HLA-B27 subtypes might be relevant in the etiopathogenesis. Fractures of the osteoporotic spine contribute to morbidity. Spinal cord injury may occur. MR imaging enables identifying sacroiliitis earlier than plain radiography. Sweet syndrome has now been described in patients with ankylosing spondylitis and Crohn disease. Progress has been made in the assessment of ankylosing spondylitis. There are now core sets for different settings and validated instruments for functioning and disease activity that will enable demonstrating efficacy of new therapeutic interventions. The debate continues on classification of postinfectious and reactive arthritis. Bacterial antigens may be found in the inflamed joints; occasionally 16S ribosomal RNA is also demonstrated. Antibiotics seem not to be effective in postenteric reactive arthritis. More than 25 years have now elapsed since the association between ankylosing spondylitis and HLA-B27 was first described in 1973. The cause of this disease is still unknown, but a lot of progress has been made regarding the molecular structure of HLA-B27, the spectrum of disease, the clinical and radiographic assessment of ankylosing spondylitis, and its treatment. Recent advances in research on ankylosing spondylitis are reviewed here.