Clinical and Pathological Features of Renal Involvement in Propylthiouracil-Associated ANCA-Positive Vasculitis

Propylthiouracil-induced vasculitis with alveolar hemorrhage after 31 years of treatment: a case report

BACKGROUND

Propylthiouracil is an antithyroid medication that is associated with ANCA positivity, often in the absence of clinically overt vasculitis. Propylthiouracil-induced ANCA-associated vasculitis (AAV) is characterized by multiple antigenicity and presents similarly to other forms of drug-induced vasculitis.

CASE PRESENTATION

We report a case of a 49-year-old woman who developed propylthiouracil-induced AAV after 31 years of intermittent therapy. The patient presented with progressive respiratory and generalized symptoms. She was diagnosed with propylthiouracil-induced AAV with alveolar hemorrhage based on detection of ANCA and anti-MPO antibodies, exclusion of primary vasculitis, and symptom resolution following propylthiouracil withdrawal. The patient was treated with intravenous methylprednisolone, followed by oral prednisolone. Her symptoms resolved, and her laboratory and radiological tests improved within one week.

CONCLUSIONS

Research linking the duration of propylthiouracil use to the development of vasculitis is restricted by multiple methodological limitations. Maintaining a high index of clinical suspicion is a more reliable approach to detecting propylthiouracil-induced AAV than regular laboratory monitoring, given that patients with Graves' disease may show ANCA positivity in the absence of medication use. Therefore, clinicians should remain vigilant for the varied presentations of propylthiouracil-induced AAV. Moreover, further research is recommended to investigate the possible link between the duration of PTU use and the onset of clinically overt vasculitis.

Characteristics and outcome of ANCA-associated vasculitides induced by anti-thyroid drugs: a multicentre retrospective case-control study

OBJECTIVE

Data on ANCA-associated vasculitis (AAV) induced by anti-thyroid drugs (ATD) are scarce. We aimed to describe the characteristics and outcome of these patients in comparison to primary AAV.

METHODS

We performed a retrospective multicentre study including patients with ATD-induced AAV. We focused on ATD-induced microscopic polyangiitis (MPA) and compared them with primary MPA by matching each case with four controls by gender and year of diagnosis.

RESULTS

Forty-five patients with ATD-induced AAV of whom 24 MPA were included. ANCA were positive in 44 patients (98%), including myeloperoxidase (MPO)-ANCA in 21 (47%), proteinase 3 (PR3)-ANCA in six (13%), and double positive MPO- and PR3-ANCA in 15 (33%). Main clinical manifestations were skin involvement (64%), arthralgia (51%) and glomerulonephritis (20%). ATD was discontinued in 98% of cases, allowing vasculitis remission in seven (16%). All the remaining patients achieved remission after glucocorticoids, in combination with rituximab in 11 (30%) or cyclophosphamide in four (11%). ATD were reintroduced in seven cases (16%) without any subsequent relapse. Compared with 96 matched primary MPA, ATD-induced MPA were younger at diagnosis (48 vs 65 years, P < 0.001), had more frequent cutaneous involvement (54 vs 25%, P = 0.007), but less frequent kidney (38 vs 73%, P = 0.02), and a lower risk of relapse (adjusted HR 0.07; 95% CI 0.01, 0.65, P = 0.019).

CONCLUSION

ATD-induced AAV were mainly MPA with MPO-ANCA, but double MPO- and PR3-ANCA positivity was frequent. The most common manifestations were skin and musculoskeletal manifestations. ATD-induced MPA were less severe and showed a lower risk of relapse than primary MPA.

Propylthiouracil-Induced Antineutrophil Cytoplasmic Antibody-Associated Vasculitis with Overlap IgA Nephropathy: A Case Report

Background

The anti-thyroid medication propylthiouracil (PTU) is a recognised cause of drug-induced antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Pauci-immune crescentic glomerulonephritis is the characteristic feature of this condition on renal biopsy. We present a case of PTU-induced AAV with the unusual histological finding of overlap IgA nephropathy (IgAN) in a young female with treatment-resistant Graves' disease.

Case Report

A 26-year-old female presented with an acute kidney injury, macroscopic haematuria, and proteinuria 14 months after starting PTU for Graves' disease. She had a history of established thyroid eye disease and a previous severe adverse reaction to carbimazole. Her autoantibodies were strongly positive for myeloperoxidase-ANCA (199 U/mL). Renal biopsy demonstrated both necrotising crescentic glomerulonephritis and prominent (3+) mesangial deposition of IgA. She was treated with glucocorticoids and rituximab with sustained improvement in her renal function but persisting mild proteinuria and microscopic haematuria. PTU was ceased following a dose of radioactive iodine (RAI). Twelve months post-RAI, her Graves' orbitopathy remained stable, and her thyroid function was gradually normalising.

Conclusion

This was a case of drug-induced AAV with histological features of overlap IgAN. We suggest that this patient had pre-existing subclinical IgAN and then developed AAV secondary to PTU. The management of her thyroid disease was complex given the PTU-induced vasculitis, previous reaction to carbimazole, the risks of a thyroidectomy on immunosuppression, and the possible worsening of her eye disease with RAI. The glucocorticoids and Rituximab prescribed for vasculitis may have prevented the progression of her Graves' orbitopathy after RAI.

The Role of Neutrophils in ANCA-Associated Vasculitis: The Pathogenic Role and Diagnostic Utility of Autoantibodies

Recent years have brought progress in understanding the role of the neutrophil, dispelling the dogma of homogeneous cells mainly involved in the prime defence against pathogens, shedding light on their pathogenic role in inflammatory diseases and on the importance of antineutrophil-cytoplasmic antibodies' pathogenic role in ANCA-associated vasculitides vasculitis (AAV). Myeloperoxidase (MPO) and proteinase 3 (PR3) expressed in neutrophil granulocytes are the most common targets for ANCAs and contribute to the formation of MPO-ANCAs and PR3-ANCAs which, released to the bloodstream, become an excellent diagnostic tool for AAV. In this study, we focus on increasing the clinical and experimental evidence that supports the pathogenic role of ANCAs in AAV. Additionally, we discuss the diagnostic utility of ANCAs for disease activity and prognosis in AAV. Understanding the central role of ANCAs in AAV is crucial for advancing our knowledge of these complex disorders and developing targeted therapeutic strategies in the era of personalized medicine.

Plasma exchange as an adjunctive therapy in anti-neutrophil cytoplasm antibody-associated vasculitis

INTRODUCTION

We summarize evidence for the role of therapeutic plasma exchange (TPE) in the treatment of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV). TPE rapidly removes ANCA IgG, complement and coagulation factors important in the pathogenesis of AAV. TPE has been used in patients with rapidly deteriorating renal function to achieve early disease control, allowing time for immunosuppressive agents to prevent resynthesis of ANCA. The PEXIVAS trial challenged the utility of TPE in AAV, as it did not show benefit of adjunctive TPE on a combined end point of end stage kidney disease (ESKD) and death.

AREAS COVERED

We analyze data from PEXIVAS and other trials of TPE in AAV, an up-to-date meta-analysis, and recently published large cohort studies.

EXPERT OPINION

There remains a role for the use of TPE in AAV in certain groups of patients, in particular those with severe renal involvement (Cr >500 μmol/L or dialysis-dependent). It should be considered in patients with Cr >300 μmol/L and rapidly deteriorating function, or with life-threatening pulmonary hemorrhage. A separate indication is patients double positive for anti-GBM antibodies and ANCA. TPE may have the greatest benefit as part of steroid-sparing immunosuppressive treatment strategies.

Old known and possible new biomarkers of ANCA-associated vasculitis

Antineutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) comprises a group of multisystem disorders involving severe, systemic, small-vessel vasculitis with short- and long term serious and life-threating complications. Despite the simplification of treatment, fundamental aspects concerning assessment of its efficacy and its adaptation to encountered complications or to the relapsing/remitting/subclinical disease course remain still unknown. The pathogenesis of AAV is complex and unique, and despite the progress achieved in the last years, much has not to be learnt. Foremost, there is still no accurate marker enabling us to monitoring disease and guide therapy. Therefore, the disease management relays often on clinical judgment and follows a" trial and error approach". In the recent years, an increasing number of new molecules s have been explored and used for this purpose including genomics, B- and T-cell subpopulations, complement system factors, cytokines, metabolomics, biospectroscopy and components of our microbiome. The aim of this review is to discuss both the role of known historical and clinically established biomarkers of AAV, as well as to highlight potential new ones, which could be used for timely diagnosis and monitoring of this devastating disease, with the goal to improve the effectiveness and ameliorate the complications of its demanding therapy.

A worldwide pharmacoepidemiological update of drug-associated ANCA-associated vasculitis at the time of targeted therapies

OBJECTIVE

The literature data supporting the role of a drug in the onset of drug-associated anti-neutrophil cytoplasmic antibody-associated vasculitis (DA-AAV) mainly rely on case reports or short series and implicate old treatments. The advent of new treatments may have modified the epidemiology of these adverse drug reactions (ADRs). We therefore aimed to update this list by using a pharmacovigilance-based data mining approach.

METHODS

We collected data on ADRs reported with the MedDRA preferred term "Anti-neutrophil cytoplasmic antibody positive vasculitis" up to November 2020 from the World Health Organization pharmacovigilance database (VigiBase^® ). For each retrieved drug, a case/noncase analysis was performed, and disproportionate reporting was calculated by using the information component (IC). A positive IC₀₂₅ value, which is the lower end of the 95% credibility interval, was considered significant.

RESULTS

A total of 483 deduplicated individual case safety reports of DA-AAV involving 15 drugs with an IC₀₂₅ >0 were retrieved. DA-AAV occurred in 264 (71.2%, n=371) women, the median age at onset was 62 years [45-72], and the median time to onset between the introduction of the suspected drug and DA-AAV was 9 months [1-36]. DA-AAV occurrence was considered serious in 472 (97.7%, n=481) cases and fatal in 43 (8.9%) cases. The drugs associated with the highest disproportionate reporting were hydralazine, propylthiouracil, thiamazole, sofosbuvir, minocycline, carbimazole, mirabegron, and nintedanib.

CONCLUSION

This study strengthens the previously suspected association but also identifies 3 new drugs that may cause DA-AAV. Particular attention should be given to these drugs by prescribers and in experimental studies.

Complement Components C3 and C4 Indicate Vasculitis Manifestations to Distinct Renal Compartments in ANCA-Associated Glomerulonephritis

Acute kidney injury (AKI) is a common and severe complication of antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) causing progressive chronic kidney disease (CKD), end-stage renal disease (ESRD) or death. Pathogenic ANCAs, in particular proteinase 3 (PR3) and myeloperoxidase (MPO), trigger a deleterious immune response resulting in pauci-immune necrotizing and crescentic glomerulonephritis (GN), a common manifestation of glomerular injury in AAV. However, there is growing evidence that activation of the complement pathway contributes to the pathogenesis and progression of AAV. We here aimed to compare glomerular and tubulointerstitial lesions in ANCA GN and extrarenal manifestation of AAV in association with levels of circulating complement components C3c and C4.

METHODS

Plasma levels of C3c and C4 in a total number of 53 kidney biopsies with ANCA GN were retrospectively included between 2015 and 2020. Glomerular and tubulointerstitial lesions were evaluated according to established scoring systems for ANCA GN and analogous to the Banff classification.

RESULTS

We here show that circulating levels of C3c and C4 in ANCA GN were comparable to the majority of other renal pathologies. Furthermore, hypocomplementemia was only detectable in a minor subset of ANCA GN and not correlated with renal or extrarenal AAV manifestations. However, low levels of circulating C3c correlated with AKI severity in ANCA GN independent of systemic disease activity or extrarenal AAV manifestation. By systematic scoring of glomerular and tubulointerstitial lesions, we provide evidence that low levels of circulating C3c and C4 correlated with vasculitis manifestations to distinct renal compartments in ANCA GN.

CONCLUSIONS

We here expand our current knowledge about distinct complement components in association with vasculitis manifestations to different renal compartments in ANCA GN. While low levels of C4 correlated with glomerulitis, our observation that low levels of circulating complement component C3c is associated with interstitial vasculitis manifestation reflected by intimal arteritis implicates that C3c contributes to tubulointerstitial injury in ANCA GN.

Comorbidities and health-related quality of life in Patients with Antineutrophil Cytoplasmic Antibody (ANCA) - associated vasculitis

BACKGROUND AND OBJECTIVES

The optimization of immunosuppressive therapies has led to a marked improvement in the survival of ANCA-associated vasculitides (AAV). The main issue now appears to be the management of comorbidities and the improvement of quality of life. The objective of this review was to investigate the incidence and the impact of AAV-associated comorbidities, as well as the determinants of health-related quality of life (HRQoL).

METHODS

We performed a systematic literature review of articles published in Medline from 2001 to 04/28/2020. We selected relevant articles about AAV-associated comorbidities as well as HRQoL and fatigue. For each selected article, data on the incidence of comorbidity were extracted, and factors associated with the Mental component score (MCS) and the Physical component score (PCS) were identified.

RESULTS

Among the 10,993 references identified, 103 were retained for the final analysis. A significant increase in cardiovascular risk was evidenced, particularly for coronary artery disease and thromboembolic events, especially during the active phase of the disease. AAV was also associated with bronchiectasis, thyroid diseases and osteoporosis. A marked decrease in HRQoL and an increase in fatigue and anxiety were reported. Decrease in PCS and MCS was associated with fatigue, mood disorders, sleep disturbance, and/or unemployment.

CONCLUSION

The excess mortality of AAV is still a concern, partly in connection with cardiovascular and thromboembolic comorbidities. AAV patients also experiment a reduction in their HRQoL that requires integrated management. Patients with AAV need comorbidity management strategies to improve their quality of life and outcomes.

An unusual presentation of propylthiouracil-induced anti-MPO and PR3 positive ANCA vasculitis with associated anti-GBM antibodies, IgA nephropathy and an IgG4 interstitial infiltrate: a case report

Background

A number of disease processes can culminate in rapidly progressive glomerulonephritis, including pauci-immune focal segmental necrotising glomerulonephritis, usually seen with positive serum antineutrophil cytoplasmic antibodies (ANCA). Propylthiouracil (PTU) has been associated with drug-induced ANCA-associated vasculitis (AAV), with antibodies against myeloperoxidase (MPO) and proteinase 3 (PR3) present individually and together having been recognised. ‘Double-positive’ vasculitis with ANCA and anti-glomerular basement membrane (GBM) antibodies has also been reported in association with PTU treatment. We present a case of PTU-induced anti-MPO and PR3 positive ANCA vasculitis with associated anti-GBM antibodies, IgA nephropathy and an IgG4 interstitial infiltrate.

Case presentation

A 51-year-old man presented 2 weeks after re-commencing propylthiouracil (PTU) treatment for Graves’ disease, with a severe acute kidney injury and haemato-proteinuria. He demonstrated positive titres for autoantibodies to PR3 (76.9 IU/mL), MPO (28.8 IU/mL) and GBM (94 IU/mL). Renal biopsy demonstrated numerous glomerular crescents, widespread IgG4-positive lymphoplasmacytic infiltrate and mesangial positivity for IgA. PTU was stopped and he was treated with steroids, plasma exchange and cyclophosphamide with sustained improvement in his renal function.

Conclusions

This case of drug-induced AAV presented a unique and intriguing collection of serological and histological features. We propose that the PTU-induced AAV resulted in epiphenomena of anti-GBM antibody production and an IgG4-cell-rich tubulointerstitial infiltrate. It is uncertain whether the mesangial IgA deposition preceded or resulted from the AAV.

Complement, infection, and autoimmunity

PURPOSE OF REVIEW

Complement system dysfunction in terms of upregulation, downregulation, or dysregulation can create an imbalance of both host defense and inflammatory response leading to autoimmunity. In this review, we aimed at describing the role of complement system in host defense to inflection and in autoimmunity starting from the evidence from primary and secondary complement system deficiencies.

RECENT FINDINGS

Complement system has a determinant role in defense against infections: deficiencies of complement components are associated with increased susceptibility to infections. Primary complement system deficiencies are rare disorders that predispose to both infections and autoimmune diseases. Secondary complement system deficiencies are the result of the complement system activation with consumption. Complement system role in enhancing risk of infective diseases in secondary deficiencies has been demonstrated in patients affected by systemic autoimmune disorders, mainly systemic lupus erythematosus and vasculitis.

SUMMARY

The relationship between the complement system and autoimmunity appears paradoxical as both the deficiency and the activation contribute to inducing autoimmune diseases. In these conditions, the presence of complement deposition in affected tissues, decreased levels of complement proteins, and high levels of complement activation fragments in the blood and vessels have been documented.

Anti-neutrophil cytoplasmic antibodies (ANCA): Antigen interactions and downstream effects

Neutrophils are the most abundant leukocytes in circulation and are key "first responders" in the immune response to infectious and non-infectious stimuli. Unlike other immune cells, neutrophils can mount a robust response (including a change in surface markers and the production of extracellular traps and reactive oxygen species) just minutes after sensing a disturbance. It has been speculated that, in some individuals, the activation of neutrophils inadvertently leads to the generation of anti-neutrophil cytoplasmic autoantibodies (ANCA) against particular neutrophil proteins (antigens) such as myeloperoxidase (MPO) and proteinase 3 (PR3). In these individuals, continuous ANCA-antigen interactions are thought to drive persistent activation of neutrophils, chronic immune activation, and disease, most notably, small vessel vasculitis. There are significant gaps however in our understanding of the underlying mechanisms and even the pathogenicity of ANCA given that vasculitis can develop in the absence of ANCA, and that ANCA have been found in circulation in other conditions with no apparent contribution to disease. These gaps are particularly evident in the context of human studies. Herein, we review knowledge on neutrophil-derived ANCA antigens PR3 and MPO, ANCA generation, and ANCA-antigen interaction(s) that may promote immune activation and disease.

Smoking Is a Risk Factor for Relapse of Antimyeloperoxidase Antibodies-Associated Vasculitis

BACKGROUND/OBJECTIVE

Several studies have identified predictors of relapse in antineutrophil cytoplasmic antibody-associated small-vessel vasculitis. However, the role of smoking as a risk factor of relapse has not been elucidated. Therefore, this study aimed to evaluate whether a history of smoking is a dose-dependent independent risk factor for antineutrophil cytoplasmic antibody-associated small-vessel vasculitis relapse.

METHODS

This multicenter retrospective cohort study included 122 patients with granulomatosis with polyangiitis and microscopic polyangiitis (MPA) from 9 nephrology centers in Japan. Dose-response relationships between cigarette smoking and outcomes were assessed using multivariate Cox proportional hazards models, adjusted for clinically relevant factors. The primary outcome was the time from remission to first relapse.

RESULTS

During the observation period (median, 41 months; interquartile range, 23-66 months), 118 (95.8%) and 34 (21.7%) patients experienced at least 1 remission and 1 relapse, respectively. A log-rank test showed that smoking was significantly associated with relapse (p = 0.003). Multivariate Cox proportional hazards models found current smoking to be associated with relapse (adjusted hazard ratio, 7.48; 95% confidence interval, 2.73-21.0). An association between the risk of relapse and cumulative pack-years of smoking was also noted (p = 0.004). Smoking, however, was not associated with remission.

CONCLUSIONS

Smoking is a significant and dose-dependent risk factor for relapse of MPA. All patients with MPA who smoke should be encouraged to quit.

Incidentally Diagnosed Alport Syndrome in a Patient with Drug-Induced Vasculitis

A 53-year-old woman is admitted with a serum creatinine of 16 mg/dl. Seven months earlier, she was diagnosed with heart failure and started on several medications, including Hydralazine. Laboratory studies revealed the presence of dual Anti-Neutrophil Cytoplasmic Antibodies (anti-MPO and anti-PR3), anti-nuclear and anti-histone antibodies. The clinical diagnosis was Drug-Induced ANCA Vasculitis (DIAV). Kidney histology, however, did not reveal crescents, but showed characteristic features of Alport's syndrome.

Pathogenesis of ANCA-Associated Pulmonary Vasculitis

Antineutrophil cytoplasmic antibodies (ANCAs) are autoantibodies specific for antigens located in the cytoplasmic granules of neutrophils and lysosomes of monocytes. ANCAs are associated with a spectrum of necrotizing vasculitis that includes granulomatosis with polyangiitis, microscopic polyangiitis, and eosinophilic granulomatosis with polyangiitis. Pulmonary vasculitis and related extravascular inflammation and fibrosis are frequent components of ANCA vasculitis. In this review, we detail the factors that have been associated with the origin of the ANCA autoimmune response and summarize the most relevant clinical observations, in vitro evidence, and animal studies strongly indicating the pathogenic potential of ANCA. In addition, we describe the putative sequence of pathogenic mechanisms driven by ANCA-induced activation of neutrophils that result in small vessel necrotizing vasculitis and extravascular granulomatous necrotizing inflammation.

Recent advances in understanding of the pathogenesis of ANCA-associated vasculitis

Anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitides (AAV) are rare systemic autoimmune diseases characterised by inflammation of small blood vessels. Recent developments have been made in our understanding of the pathogenesis of these diseases, including the pathogenic role of ANCA, neutrophils and monocytes as mediators of injury, dysregulation of the complement system, and the role of T and B cells. Current treatment strategies for AAV are based on broad immunosuppression, which may have significant side effects. Advances in understanding of the pathogenesis of disease have led to the identification of new therapeutic targets which may lead to treatment protocols with less-toxic side effects. The aim of this review is to summarise current information and recent advances in understanding of the pathogenesis of AAV.

Propylthiouracil-Associated Leukocytoclastic Necrotizing Cutaneous Vasculitis: A Case Report and Review of the Literature

The purpose of this case report and review of the literature is to provide an exploration of the clinical symptoms, diagnosis, prevention, and management of propylthiouracil (PTU)-associated vasculitis in the intensive care setting. A PubMed search of the available literature was conducted using the MeSH search terms "propylthiouracil" and "vasculitis." The literature search returned 121 articles. Twenty-five were excluded because they were not in English. Fifty-nine case reports or case studies describing PTU-associated vasculitis were included. Data extracted from each case study included patient age, sex, autoimmune markers, laboratory tests, length of time on PTU, treatment for vasculitis, and patient outcomes. The authors reviewed 128 cases of PTU-associated vasculitis. The majority were women (8.8:1 F:M ratio), and the most common presenting symptoms were rash (51.6%), fever (46.9%), and arthralgia (43.8%). In addition to discontinuing PTU, the most common treatment was steroids (71.9%). Eight patients (6.3%) progressed to end-stage renal disease; two (1.6%) required intubation for respiratory failure; and five (3.9%) died of various organ systems failure related to vasculitis development. A high index of suspicion for vasculitis should be maintained, especially when presented with skin manifestations in the presence of PTU therapy. Screening with myeloperoxidase-antinuclear cytoplasmic antibodies is most sensitive. Positive screening should prompt a thorough clinical investigation. In cases of severe skin manifestations, the focus should be on aggressive wound care. Our case report is unique, not only in the size and extent of cutaneous involvement, but also as the first description of mortality secondary to cutaneous manifestations.

ANCA-positive vasculitis: Clinical implications of ANCA types and titers

INTRODUCTION

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is an autoimmune disease that can affect multiple organs, the kidney being one of the most affected. Apart from the diagnostics value of ANCA, they have also been advocated as biomarkers of the disease activity. Recently, the genetic changes found in polyangiitis associated with serine-protease proteinase 3 (PR3)-ANCA or myeloperoxidase (MPO)-ANCA raised the possibility of immune-pathogenic and therapeutic differences.

OBJECTIVE

To identify differences in the number of relapses, inflammatory markers, outcomes and renal histology related to the types of ANCA. To analyze the implications of ANCA titers in prognosis.

METHOD

A retrospective observational study in a Portuguese tertiary hospital.

RESULTS

There were no differences in the progression of renal function, histological pattern and initial treatment with regard to ANCA subtypes. As for the evaluated parameters, there were no significant differences according to the types of ANCA, except for mean CRP values within the normal range, which was 6.3±1.3 mg/L for MPO-ANCA and 12.4±10.14 mg/L for PR3-ANCA (p=0.04). We found that 66.7% of the MPO-ANCA-positive showed no relapses versus 40% in the case of PR3-ANCA-positive. There was no correlation between the ANCA titers at presentation, during remission, and in the last evaluation, and the number of relapses.

CONCLUSION

PR3-ANCA patients have a mean CRP value within the normal range significantly higher than that of MPO-ANCA patients (p=0.04), which seems to reveal greater inflammatory activity in the first.

Anti-Nuclear Cytoplasmic Antibody-Associated Vasculitis: A Probable Adverse Effect of Sofosbuvir Treatment in Chronic Hepatitis C Patients

Background: Egypt has the largest hepatitis C virus (HCV) epidemic worldwide. Sofosbuvir is an antiviral drug acting by inhibition of the HCV NS5B polymerase. It has shown high efficacy in combination with several other drugs and has a low reported rate of side effects. Objective: The aim of this prospective cohort study was to assess the safety of sofosbuvir-based treatment regimens used to treat chronic hepatitis C infections and to detect any side effects of sofosbuvir not previously reported. Methods: We studied treatment side effects in 3,000 patients with chronic HCV infection treated with sofosbuvir and ribavirin for 24 weeks or treated by pegylated interferon, sofosbuvir, and ribavirin triple therapy for 12 weeks. The endpoint of the study was the end of treatment. Results: Hyperbilirubinemia occurred frequently during treatment in both groups. Treatment was discontinued in 72 cases due to hepatic decompensation and drug complications; 8 of the cases had deep vein thrombosis (DVT) and 7 had cerebral ischemia. Surprisingly, 177/3,000 (5.9%) patients presented with abnormal bleeding, 85 of whom had a vasculitic skin rash. Conclusion: We report the occurrence of previously nonrecorded side effects with sofosbuvir, namely DVT and bleeding disorders associated with anti-nuclear cytoplasmic antibody (ANCA)-associated vasculitis (AAV).We believe this to be the first report of sofosbuvir-induced AAV skin lesions and bleeding disorders.

Complement in ANCA-associated vasculitis: mechanisms and implications for management

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of potentially life-threatening autoimmune diseases. The main histological feature in the kidneys of patients with AAV is pauci-immune necrotizing crescentic glomerulonephritis with little immunoglobulin and complement deposition in the glomerular capillary walls. The complement system was not, therefore, initially thought to be associated with the development of AAV. Accumulating evidence from animal models and clinical observations indicate, however, that activation of the complement system - and the alternative pathway in particular - is crucial for the development of AAV, and that the complement activation product C5a has a central role. Stimulation of neutrophils with C5a and ANCA not only results in the neutrophil respiratory burst and degranulation, but also activates the coagulation system and generates thrombin, thus bridging the inflammation and coagulation systems. In this Review, we provide an overview of the clinical, in vivo and in vitro evidence for a role of complement activation in the development of AAV and discuss how targeting the complement system could provide opportunities for therapy.

Thyroid dysfunction and kidney disease: An update

Thyroid hormones influence renal development, kidney hemodynamics, glomerular filtration rate and sodium and water homeostasis. Hypothyroidism and hyperthyroidism affect renal function by direct renal effects as well as systemic hemodynamic, metabolic and cardiovascular effects. Hypothyroidism has been associated with increased serum creatinine and decreased glomerular filtration rate. The reverse effects have been reported in thyrotoxicosis. Most of renal manifestations of thyroid dysfunction are reversible with treatment. Kidney disease may also cause thyroid dysfunction by several mechanisms. Nephrotic syndrome has been associated to changes in serum thyroid hormone concentrations. Different forms of glomerulonephritis and tubulointerstitial disease may be linked to thyroid derangements. A high prevalence of thyroid hormone alteration has been reported in acute kidney injury. Thyroid dysfunction is highly prevalent in chronic kidney disease patients. Subclinical hypothyroidism and low triiodothyronine syndrome are common features in patients with chronic kidney disease. Patients treated by both hemodialysis and peritoneal dialysis, and renal transplantation recipients, exhibit thyroid hormone alterations and thyroid disease with higher frequency than that found in the general population. Drugs used in the therapy of thyroid disease may lead to renal complications and, similarly, drugs used in kidney disorders may be associated to thyroid alterations. Lastly, low thyroid hormones, especially low triiodothyronine levels, in patients with chronic kidney disease have been related to a higher risk of cardiovascular disease and all-cause mortality. Interpretation of the interactions between thyroid and renal function is a challenge for clinicians involved in the treatment of patients with thyroid and kidney disease.

The Prevalence and Management of Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis in China

BACKGROUND

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) comprises microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA) and eosinophilic GPA (EGPA). Myeloperoxidase (MPO) and proteinase 3 (PR3) are the main antigens for ANCA. AAV is a common multisystem autoimmune disease and most of the studies on AAV have been conducted in Western countries. Nowadays in China many efforts are made to investigate this disease.

SUMMARY

This review highlights the progress in the prevalence, management and outcomes of AAV in Chinese patients. With respect to the prevalence of AAV, though there are no precise data, AAV is not rare in the Chinese population. In Chinese patients with AAV there is a striking preponderance of MPA, and MPO-ANCA is much more common than PR3-ANCA. Even in patients with GPA there is a predominance of MPO-ANCA over PR3-ANCA. Propylthiouracil-induced AAV and ANCA-negative pauci-immune glomerulonephritis are stated in this review as well. With respect to the management of AAV, glucocorticoids in combination with cyclophosphamide remain the mainstay of induction therapy. Besides, we describe predictors of different outcomes in Chinese patients, including mortality, relapse, treatment resistance and end-stage renal disease.

KEY MESSAGES

AAV is not rare in the Chinese population. The disease spectrum and subtypes of ANCA are different between patients with AAV in China and Western countries. The treatment strategy for AAV in China is in consistency with that in Western countries. Predictors of different clinical outcomes are provided.

FACTS FROM EAST AND WEST

Treatment options for AAV are shared between the East and West, with corticosteroid combined with cyclophosphamide being the standard regimen for inductive therapy and switching to azathioprine after remission. The major cause of death in treated patients is infection related to immunosuppressive therapy within the first year after diagnosis, and this rate might be higher in China than in Western countries. Western studies demonstrated the efficacy and safety of rituximab for induction of remission in cases with relatively mild disease and maintenance therapy, but this agent is rarely used in China.

Classification, epidemiology and clinical subgrouping of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis

It is now 25 years since the first European studies on vasculitis--the anti-neutrophil cytoplasmic antibody (ANCA) standardization project. Over that period of time, there have been major developments in the classification of the vasculitides, which has permitted the conduct of high-quality epidemiology studies. Studying the epidemiology of rare diseases such as the ANCA-associated vasculitides (AAV) poses considerable challenges to epidemiologists. The first is the need for a clear definition of a case with good differentiation from similar disorders. The second is case capture. The vasculitides are rare, and therefore, a large population is required to determine the incidence and prevalence, and this poses questions of feasibility. A large population increases the risk of incomplete case detection but permits a reasonable number of cases to be collected in a practicable time frame, whereas a smaller population requires a much longer time frame to collect the necessary cases, which may also not be feasible. Statistical methods of capture-recapture analysis enable estimates to be made of the number of missing cases. The third is case ascertainment. The AAV are virtually always managed in secondary care, and therefore, hospital-based case ascertainment may be appropriate. Fourthly, the rarity of the conditions makes prospective case-control studies investigating risk factors difficult to conduct because the population size required to achieve statistical confidence is in excess of that which is readily available. Thus, much of the data on risk factors are derived from retrospective studies with inherent potential bias.

Clinical features of children with pulmonary microscopic polyangiitis: report of 9 cases

Kidneys and lungs are the most common organs involved in microscopic polyangiitis (MPA). A retrospective analysis of pediatric MPA patients with pulmonary lesions over the past 10 years was performed to investigate clinical features of MPA in children with pulmonary lesions. There were 9 patients enrolled in our study, including 2 boys and 7 girls, with a median age of 6.6 years at the time of disease onset and a median disease course of 2 months. All of the patients exhibited tachypnea, and 7 exhibited cough and hemoptysis. The most common presentation on pulmonary imaging was ground glass or patchy shadows, which were observed in 6 cases. Seven patients manifested with hematuria and proteinuria, with renal histopathology of fibrinoid necrosis/exudation of the glomerular capillaries. All of the patients presented with normocytic normochromic anemia. Of the 9 patients, 7 were positive for perinuclear antineutrophil cytoplasmic antibody (p-ANCA) and/or myeloperoxidase (MPO), and 2 were positive for p-ANCA/MPO and cytoplasmic ANCA/proteinase 3. Eight patients had normal complement 3 (C3) levels, and one had an elevated C3 level. Five of the 9 patients were positive for antinuclear antibody ANA, and 4 were positive for double strand DNA (ds-DNA) antibody (3 were positive for both). The 7 patients who exhibited renal involvement received steroid plus cyclophosphamide (CTX) treatment. Of these patients, 4 achieved various degrees of remission, 2 were at the beginning of induction therapy, and one was lost to follow-up. Two patients with isolated pulmonary involvement received steroid plus leflunomide treatment and achieved complete remission. Diffuse alveolar hemorrhage was the most frequent presentation of lung involvement in children with MPA, and tachypnea, cough, hemoptysis and anemia were the common clinical symptoms. The majority of these patients exhibited hematuria, proteinuria and renal insufficiency. The efficacy of steroid plus CTX or leflunomide was evident in these patients.

A Case of Concurrent MPO-/PR3-Negative ANCA-Associated Glomerulonephritis and Membranous Glomerulopathy

We report a case in which antineutrophil cytoplasmic antibody- (ANCA-) associated glomerulonephritis and membranous glomerulopathy (MGN) were detected concurrently. The patient showed rapidly progressive renal deterioration. A renal biopsy showed crescentic glomerulonephritis, together with marked thickening and spike and bubbling formations in the glomerular basement membranes. Indirect immunofluorescence examination of the patient's neutrophils showed a perinuclear pattern. Enzyme-linked immunosorbent assays revealed that the ANCA in this case did not target myeloperoxidase (MPO) or proteinase 3 (PR3) but bactericidal-/permeability-increasing protein, elastase, and lysosome. The relationship between these two etiologically distinct entities, MPO-/PR3-negative ANCA-associated glomerulonephritis and MGN, remains unclear.

Bucillamine-induced membranous nephropathy with crescent formation in a patient with rheumatoid arthritis: case report and literature review

Bucillamine is a disease-modifying antirheumatic drug that is structurally similar to D-penicillamine. The major renal side effect of bucillamine and D-penicillamine is proteinuria caused by membranous nephropathy (MN). In addition to MN, combined crescent formation has been occasionally reported in D-penicillamine-induced MN, while crescent formation has been rarely reported in bucillamine-treated cases. Here, we describe a 76-year-old female who presented with nephrotic syndrome and rapidly progressive glomerulonephritis. She was receiving bucillamine as initial treatment for recently diagnosed rheumatoid arthritis, and renal biopsy showed MN with crescent formation. To the best of our knowledge, this is the first report of bucillamine-induced MN with crescent formation in the English literature.

Propylthiouracil-associated rapidly progressive crescentic glomerulonephritis with double positive anti-glomerular basement membrane and antineutrophil cytoplasmic antibody: the first case report

We report a case of propylthiouracil (PTU)-induced double antineutrophil cytoplasmic antibody (ANCA) and anti-glomerular basement membrane antibody (anti-GBM antibody) disease causing pulmonary-renal syndrome in a 35-year-old Thai woman with 10-year history of PTU treatment for thyrotoxicosis. She developed clinical symptoms of vasculitis upon receiving long-term PTU treatment. Prednisolone treatment and the switching from PTU to methimazole resulted to short-term clinical improvement. Nevertheless following termination of steroid treatment, she developed recurrent pulmonary hemorrhage and rapidly progressive glomerulonephritis. The kidney biopsy showed crescentic glomerulonephritis with linear IgG deposit on the glomerular basement membrane although transbronchial lung biopsy showed no immune deposit along the alveolar basement membrane. Serum testing for p-ANCA was positive and western blot showed positive antibody to the alpha-3 chain of collagen type IV. Both ANCA and anti-GBM antibody may play a role in the development of end organ damage. To facilitate early and specific intervention, clinicians should be aware of the propensity of PTU to cause lupus-like syndromes with renal involvement. In patients with PTU-induced ANCA-associated glomerulonephritis, serum anti-GBM antibody test may be useful in the early diagnosis of double positive antibodies disease and plasmapheresis should be performed without delay.

ANCA Associated Vasculitis and Renal Failure Related to Propylthiouracil and Hyperthyroidism Induced Cholestasis in the Same Case

Introduction. Liver involvement due to hyperthyroidism and also ANCA positive vasculitis related renal failure cases were reported separately several times before. However, to our knowledge, these two complications together in the same case had never been observed before. Case Presentation. The case of an ANCA positive 71-year-old Caucasian male with renal failure and lung involvement, subclinical hyperthyroidism, and intrahepatic cholestatic jaundice was presented in this paper. After exclusion of all of the other possibilities, cholestatic hepatitis was explained by subclinical hyperthyroidism; renal failure and lung involvement were interpreted as ANCA related vasculitis which might be a side effect of propylthiouracil use. Conclusion. The coexistence of these rare conditions in the same patient deserves emphasis and it is worth reporting. This case demonstrates that following the clinical course of the patient is essential after prescribing any medications to see whether any complication occurs or not. If the complications of this case were noticed earlier, it would be possible to treat and to prevent the permanent damages.

Clinical and Pathological Features of Microscopic Polyangiitis in 20 Children

Objective.

To explore the clinical and pathological features of microscopic polyangiitis (MPA) in children.

Methods.

A retrospective analysis was performed of patients with pediatric MPA in our hospital over 10 years.

Results.

Data for 20 patients were collected; 16 patients had primary MPA (4 boys, 12 girls), with a median age of 8.9 years at the time of disease onset; 4 patients, all female, had antithyroid drug (ATD)-associated MPA, with an age range of 12.5 to 16.2 years at the time of disease onset. All patients exhibited renal involvement. Renal biopsies were performed in 14 patients. Fibrinoid exudation and necrosis of the glomerular capillaries were observed in all biopsy specimens. Crescents and scleroses were noted in 92.9% and 85.7% of these cases, respectively. The most frequent extrarenal organs involved were lungs, followed by the central nervous system (CNS), skin, and digestive system. Ninety percent of patients were positive for perinuclear antineutrophil cytoplasmic antibody, 94.1% were positive for myeloperoxidase, and 88.2% were positive for both. Forty-five percent of the patients had received steroid plus cyclophosphamide (CTX) pulse therapy for more than 3 months, and varying degrees of remission had been achieved in 88.9% of the patients.

Conclusion.

Both primary and ATD-associated MPA showed a female predisposition. Renal involvement was the most frequently observed condition, followed by involvement of lungs. CNS involvement was not rare in these pediatric patients. The efficacy of steroid plus CTX as induction therapy was evident in these patients.

Clinico-pathological features and outcomes of patients with propylthiouracil-associated ANCA vasculitis with renal involvement

OBJECTIVE

To retrospectively investigate clinico-pathological features and outcomes of patients with renal involvement in propylthiouracil (PTU)-associated antineutrophil cytoplasmic autoantibody (ANCA) vasculitis (PTU-AAV).

METHODS

Clinico-pathological features and outcomes of 12 patients (female 11, average age 32.4 ± 13.8 years) who developed AAV after treatment with PTU were collected and analyzed. ANCA was detected by both immunofluorescence (IF) and enzyme linked immunosorbent assay (ELISA). All patients had renal biopsy.

RESULTS

Twelve patients received PTU for 2-264 months (median 42 months) when PTUAAV was diagnosed. All patients had positive serum P-ANCA, 11 of them were MPO-ANCA, 1 was MPO and PR3-ANCA double positive. All patients presented with hematuria and proteinuria, 5 of them had gross hematuria, urine protein was 1.9 ± 1.6 g/24 h, 7 of 12 (58.3%) patients had renal dysfunction, among them 3 needed initial renal replacement therapy. Renal biopsy showed pauci-immune segmental necrotizing crescentic glomerulonephritis in ten patients, segmental necrotizing glomerulonephritis superimposed on membranous nephropathy in two patients. All patients withdrew PTU and received steroid and immunosuppressive therapy. After a median follow-up of 42 months (range 21-86), 3 patients developed to ESRD, 7 patients entered complete renal remission. Serum ANCA turned negative only in 2 patients, 10 patients had persistent positive serum ANCA. Three patients relapsed with the elevation of serum ANCA level.

CONCLUSION

Renal damage of PTU-AAV could be pauci-immune necrotizing crescentic glomerulonephritis, and necrotizing glomerulonephritis coexisted with membranous nephropathy. Most patients had persistent positive serum ANCA and had a risk of relapse and progression to ESRD even after PTU withdrawal and immunosuppressive therapy.

The thyroid and the kidney: a complex interplay in health and disease

Thyroid hormones may directly affect the kidney and altered kidney function may also contribute to thyroid disorders. The renal manifestations of thyroid disorders are based on hemodynamic alterations or/and to direct effects of thyroid hormones. The renin-angiotensin system plays a crucial role in the cross-talk between the thyroid and the kidney. Hypothyroidism may be accompanied by an increase of serum creatinine and reduction of glomerular filtration rate (GFR), whereas hyperthyroidism may increase GFR. Treatment of thyroid disorders may lead to normalization of GFR. Primary and subclinical hypothyroidism and low triiodothyronine (T3) syndrome are common features in patients with chronic kidney disease (CKD). In addition low levels of thyroid hormones may predict a higher risk of cardiovascular and overall mortality in patients with end-stage renal disease. The causal nature of this correlation remains uncertain. In this review, special emphasis is given to the thyroid pathophysiology, its impact on kidney function and CKD and the interpretation of laboratorial findings of thyroid dysfunction in CKD.

Clinical study of renal impairment in patients with propylthiouracil-induced small-vessel vasculitis and patients with primary ANCA-associated small-vessel vasculitis

The aim of this study was to compare renal impairment in patients with propylthiouracil (PTU)-induced small-vessel vasculitis and patients with primary anti-neutrophil cytoplasmic antibody (ANCA)-induced small-vessel vasculitis. The study compared the pathology and clinical conditions of 10 patients with PTU-associated small-vessel vasculitis and 18 patients with primary ANCA-associated small-vessel vasculitis. All patients showed manifestations of renal impairment. Compared with the primary ANCA-induced small-vessel vasculitis, patients with PTU-induced small-vessel vasculitis were mostly female (P<0.05) and deleloped the disease at a younger age (P<0.05). They had a higher positive rate of perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA; P<0.05), lower 24 h proteinuria content, lower serum creatinine (P<0.05) and milder histopathological lesions (P<0.05). A number of them had gross hematuria (P<0.05). They rarely used hormone and cytotoxic drugs (P<0.05) during treatment and had a better prognosis (P<0.05). In conclusion, PTU-induced small-vessel vasculitis has a milder pathology and clinical manifestations with a better prognosis.

Propylthiouracil-induced antineutrophil cytoplasmic antibody-associated vasculitis

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) refers to a group of potentially life-threatening autoimmune diseases. A recent development in this field is the recognition that certain drugs can induce AAV. Among these agents, the drug most often implicated in causing disease is the commonly used antithyroid agent propylthiouracil (PTU). This Review provides an update on PTU-induced AAV. Clinical characteristics of PTU-induced AAV are similar to that of primary AAV, but usually have a milder course and better prognosis, provided early cessation of the disease-causing drug. PTU-induced ANCAs usually react to several components of myeloid granules, which is helpful in differentiating PTU-induced AAV from primary AAV. Early cessation of PTU is crucial in the treatment of PTU-induced AAV. The duration of immunosuppressive therapy might be shorter than in primary AAV, depending on the severity of organ damage, and maintenance therapy is not always necessary.

Interactions between thyroid disorders and kidney disease

There are several interactions between thyroid and kidney functions in each other organ's disease states. Thyroid hormones affect renal development and physiology. Thyroid hormones have pre-renal and intrinsic renal effects by which they increase the renal blood flow and the glomerular filtration rate (GFR). Hypothyroidism is associated with reduced GFR and hyperthyroidism results in increased GFR as well as increased renin - angiotensin - aldosterone activation. Chronic kidney disease (CKD) is characterized by a low T3 syndrome which is now considered a part of an atypical nonthyroidal illness. CKD patients also have increased incidence of primary hypothyroidism and subclinical hypothyroidism. The physiological benefits of a hypothyroid state in CKD, and the risk of CKD progression with hyperthyroidism emphasize on a conservative approach in the treatment of thyroid hormone abnormalities in CKD. Thyroid dysfunction is also associated with glomerulonephritis often by a common autoimmune etiology. Several drugs could affect both thyroid and kidney functions. There are few described interactions between thyroid and renal malignancies. A detailed knowledge of all these interactions is important for both the nephrologists and endocrinologists for optimal management of the patient.

Propylthiouracil-induced antineutrophil cytoplasmic antibody (ANCA)-associated renal vasculitis versus primary ANCA-associated renal vasculitis: a comparative study

OBJECTIVE

Renal involvement is frequently present in primary antineutrophil cytoplasmic antibody-associated small-vessel vasculitis (AAV) as well as propylthiouracil (PTU)-induced AAV. We analyzed the characteristics of patients with PTU-induced AAV with renal involvement and investigated the differences of the 2 diseases.

METHODS

Thirty-six patients with PTU-induced AAV, diagnosed from 1997 to 2010, were enrolled for study. Their data were compared with those of 174 patients with primary AAV diagnosed at the same time. Renal involvement was present in all patients.

RESULTS

There was a prominent proportion of young women with PTU-induced AAV (p < 0.01). They had lower levels of proteinuria and serum creatinine and higher estimated glomerular filtration rate (p < 0.01, p < 0.01, and p < 0.01, respectively). Clinical immunological abnormalities were less severe in patients with PTU-induced AAV. Patients with PTU-induced AAV had less organ involvement and lower Birmingham Vasculitis Assessment Score than patients with primary AAV (p < 0.01). Renal biopsies showed a lower proportion of glomeruli with crescents (p < 0.01). Interstitial inflammation was less severe in patients with PTU-induced AAV (p < 0.05). Similarly, interstitial fibrosis and tubular atrophy were less severe in patients with PTU-induced AAV (p < 0.01, p < 0.05, respectively). Renal survival and total survival were better in patients with PTU-associated vasculitis (p < 0.05, p = 0.01).

CONCLUSION

Clinical and histopathological abnormalities were less severe in patients with PTU-induced AAV and most of them had a good prognosis.

PTU-induced ANCA-positive vasculitis: an innocent or a life-threatening adverse effect?

Antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitides are rare, but they can be triggered by chemicals, infections and drugs; among them, antithyroid drugs are common. Autoimmune disorders, such as vasculitis, are unusual, but serious complications of antithyroid therapy. Both propylthiouracil (PTU) and methimazole may induce ANCA-associated vasculitis. PTU-induced vasculitides may have different organ involvement patterns. Herein, we report four cases with ANCA-associated vasculitis with different clinical manifestations.

Novel nephrotoxins

Drug and xenobiotic toxicity is an important cause of kidney injury, especially in vulnerable patients. Nephrotoxic syndromes include functional disorders; vascular injury, such as thrombotic microangiopathy; glomerular injury resulting in nephrotic syndrome or glomerulonephritis; acute tubular necrosis; acute interstitial nephritis; and crystalopathy/nephrolithiasis. Recently reported nephrotoxins are reviewed in the context of these syndromes of kidney injury.

Differential deposition of C4d and MBL in glomeruli of patients with ANCA-negative pauci-immune crescentic glomerulonephritis

OBJECTIVE

Our previous study suggested involvement of alternative pathway activation of complement in ANCA-positive pauci-immune crescentic glomerulonephritis (CrGN). This study was to investigate the evidence of complement activation in renal biopsy specimens of patients with ANCA-negative pauci-immune CrGN.

METHODS

Renal biopsy specimens from 12 patients with ANCA-negative pauci-immune CrGN were used to detect the staining of membrane attack complex (MAC), C3d, C4d, mannose-binding lectin (MBL), factor B by immunohistochemistry, and/or immunofluorescence. Renal tissue from eight patients with minimal change disease (MCD) and renal tissue obtained from a normal kidney and the normal parts of a nephrectomized kidney due to renal carcinoma was used as disease and normal controls, respectively.

RESULTS

MAC and C3d could be detected in the active renal lesions of cellular crescents in each of the 12 ANCA-negative CrGN patients but not or scarcely detected in patients with MCD and in normal renal tissue. The deposition of other complement components in the 12 patients was heterogeneous. Although none of them had C1q staining, eight of the 12 were C4d positive and six out of the eight were MBL positive. The remaining four only had evidence of the alternative pathway activation by positive staining of C3d, factor B, and MAC. The staining intensity of C4d and MBL was much higher in dialysis-dependent patients than that in dialysis-independent patients.

CONCLUSION

Complement activation was involved in renal damage of human ANCA-negative pauci-immune CrGN but with heterogeneous activation pathways. Positive staining of C4d and MBL might be associated with poor renal outcome.

Thyroid dysfunction and kidney disease

Thyroid hormones (TH) are essential for an adequate growth and development of the kidney. Conversely, the kidney is not only an organ for metabolism and elimination of TH, but also a target organ of some of the iodothyronines' actions. Thyroid dysfunction causes remarkable changes in glomerular and tubular functions and electrolyte and water homeostasis. Hypothyroidism is accompanied by a decrease in glomerular filtration, hyponatremia, and an alteration of the ability for water excretion. Excessive levels of TH generate an increase in glomerular filtration rate and renal plasma flow. Renal disease, in turn, leads to significant changes in thyroid function. The association of different types of glomerulopathies with both hyper- and hypofunction of the thyroid has been reported. Less frequently, tubulointerstitial disease has been associated with functional thyroid disorders. Nephrotic syndrome is accompanied by changes in the concentrations of TH due primarily to loss of protein in the urine. Acute kidney injury and chronic kidney disease are accompanied by notable effects on the hypothalamus-pituitary-thyroid axis. The secretion of pituitary thyrotropin (TSH) is impaired in uremia. Contrary to other non-thyroidal chronic disease, in uraemic patients it is not unusual to observe the sick euthyroid syndrome with low serum triodothyronine (T(3)) without elevation of reverse T(3) (rT(3)). Some authors have reported associations between thyroid cancer and kidney tumors and each of these organs can develop metastases into the other. Finally, data from recent research suggest that TH, especially T(3), can be considered as a marker for survival in patients with kidney disease.

Drug-induced Kidney Disease – Pathology and Current Concepts

The kidneys can be damaged by a large number of therapeutic agents. The aim of this article is to discuss the pathological features of drug-induced renal disease as diagnosed by kidney biopsy. The literature is reviewed and cases seen by the authors that have a known drug association are analysed. Mechanisms of injury are varied and all renal structures may be affected. The tubulointerstitial compartment is most frequently involved, but glomerular and vascular lesions are seen in a significant proportion of cases. Key words: Drug, Kidney, Nephrotoxicity, Pathology

Churg-Strauss Syndrome following PTU Treatment

Propylthiouracil (PTU) is a frequently prescribed drug in the treatment of hyperthyroidism. The use of PTU is, however, accompanied by numerous potentially serious side effects including vasculitis. PTU-related vasculitides can present as haematuria, pulmonary haemorrhage, or cutaneous lesion together with aspecific symptoms such as fever, myalgia, arthralgia, and fatigue. Cerebral involvement is seldom observed. We present a 49-year-old female with Graves' disease and asthma, who developed paresis of the proximal extremities, eosinophilia, pulmonary, and cutaneous lesions following treatment with PTU. A cerebral vasculitis consistent with Churg-Strauss syndrome (CSS) was suspected. Although cerebral involvement is seldom observed with PTU treatment, cerebral vasculitis should be considered in patients developing CNS symptoms.