The relationship between chikungunya virus and the kidneys: A scoping review.

Several atypical forms of chikungunya fever (CHIK) have been described, including neurological, cardiac and renal involvement. These forms may be related to high morbidity and mortality rates. This scoping review based on the PubMed, Scopus, and WOS databases aims to identify and summarise all the available evidence regarding the clinical and histopathological presentations and risk factors associated with kidney injury related to CHIK, as well as the clinical impact. Thus, a total of 54 papers were selected from 1606 initial references after applying the defined inclusion criteria. Data on the association between kidney injury and CHIK are scarce, with studies only conducted in the acute phase of the disease, lacking further characterisation. Kidney injury incidence in hospitalised patients using the Kidney Disease Improving Global Outcomes criteria varies from 21% to 45%, being higher among patients with atypical and severe manifestations. Although acute kidney injury does not seem to be related to viraemia, it may be related to higher mortality. Few studies have described the renal histopathological changes in the acute phase of CHIK, with prevalent findings of acute interstitial nephritis with mononuclear infiltrate, glomerular congestion and nephrosclerosis. Only one study assessed the kidney function of patients in the subacute and chronic phases of CHIK. Additionally, individuals with comorbidities, including chronic kidney disease, may be among those with a greater risk of presenting worse outcomes when affected by CHIK. The results described herein may contribute to better understand the relationship between the kidneys and chikungunya virus.

ANCA-associated glomerulonephritis and lupus nephritis following COVID-19 vaccination: a case report and literature review.

With the coverage of COVID-19 vaccination, it has been possible to observe the potential side effects of SARS-CoV-2 vaccines, with the most common ones being fever, myalgia, headache, and fatigue. However, an association has been observed between new and recurrent kidney injuries, mainly glomerulonephritis and lupus nephritis associated with ANCA, with the Pfizer-BioNTech, Moderna, Sinovac, and AstraZeneca vaccines, although the relationship between them is not clear. We report a case of ANCA-related vasculitis and lupus glomerulonephritis after the second dose of the AstraZeneca vaccine. The elderly patient presented significant worsening of kidney function after immunosuppression and complications after a new onset COVID-19 infection that led to death. We provide a literature review about kidney damage related to ANCA vasculitis after COVID-19 vaccine, aiming for a better understanding of the pathophysiological mechanism of kidney injury, its presentation, and treatment.

Kidney injury associated with COVID-19 infection and vaccine: A narrative review.

The respiratory tract is the main infection site for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), resulting in many admissions to intensive care centers in several countries. However, in addition to lung involvement, kidney injury caused by the novel coronavirus has proven to be a significant factor related to high morbidity and mortality, alarming experts worldwide. The number of deaths has drastically reduced with the advent of large-scale immunization, highlighting the importance of vaccination as the best way to combat the pandemic. Despite the undeniable efficacy of the vaccine, the renal side effects associated with its use deserve to be highlighted, especially the emergence or reactivation of glomerulopathies mentioned in some case reports. This study aimed to identify the main renal morphological findings correlated with COVID-19 infection and its vaccination, seeking to understand the pathophysiological mechanisms, main clinical features, and outcomes.

Long-Term Persistence of Serum-Specific Anti-Chikungunya IgM Antibody - A Case Series of Brazilian Patients.

The persistence of serum-specific anti-chikungunya IgM antibodies (CHIKV-IgM) can vary after chikungunya fever (CHIK) infection. However, the factors related to its production are not yet known. We described a case series drawn up from data collected from 57 patients between 12 and 36 months after the acute phase of CHIK infection in Northeastern Brazil. CHIKV-IgM was detectable in 7/57 (12.3%) patients after 28.3 months of infection. No frequency differences in chronic musculoskeletal manifestations and underlying conditions were detected between patients with or without CHIKV-IgM. CHIKV-IgM was detected for up to 35 months in Brazilian patients after CHIK infection.

Long-Term Persistence of Serum-Specific Anti-Chikungunya IgM Antibody - A Case Series of Brazilian Patients

Abstract The persistence of serum-specific anti-chikungunya IgM antibodies (CHIKV-IgM) can vary after chikungunya fever (CHIK) infection. However, the factors related to its production are not yet known. We described a case series drawn up from data collected from 57 patients between 12 and 36 months after the acute phase of CHIK infection in Northeastern Brazil. CHIKV-IgM was detectable in 7/57 (12.3%) patients after 28.3 months of infection. No frequency differences in chronic musculoskeletal manifestations and underlying conditions were detected between patients with or without CHIKV-IgM. CHIKV-IgM was detected for up to 35 months in Brazilian patients after CHIK infection.

Mannose-Binding Lectin2 Gene Polymorphism and IgG4 in Membranous Nephropathy.

BACKGROUND: Idiopathic membranous nephropathy (IMN) has been linked to the lectin pathway, IgG4 and genetic susceptibility. We investigated the frequency of mannose-binding lectin2 (MBL2) gene polymorphisms and the serum ratio of IgG4 in patients with membranous nephropathy (MN). METHODS: Polymorphisms in the exon 1 of the MBL2 gene (codons 52, 54, and 57) and single base polymorphisms at positions -550 (HL) and -221 (XY) in the promoter region were evaluated in 60 patients compared to a control group (CG) of 101 blood donors. It established the frequency of polymorphisms and the serum ratio of IgG4 comparing 2 etiologies of MN: idiopathic (35 patients) and secondary to systemic lupus erythematosus (25 patients). RESULTS: Patients with MN had a 2.54-fold higher probability (95% CI 1.51-4.31) of carrying the O alelle, exon 1 variant, and 11.16-fold higher probability (95% CI 4.77-28.41) of having A/O genotype when compared to CG. The frequency of polymorphisms in the promoter region was similar between the groups. Combined genotypes generally related to the defective production of MBL (YA/O, XA/O and O/O) were more frequent in patients with MN (OR 7.11; 95% CI 2.69-21.27), when compared to controls. The median of serum ratio IgG4 was 5% for idiopathic MN and 3% for lupus MN patients (p = 0.016). CONCLUSIONS: Our data suggests that MBL2 polymorphisms may be associated with the activation of the lectin pathway by IgG4 subclass antibodies in MN.

O papel da IgG4 na fisiopatogenia da nefropatia membranosa idiopática: estado da arte / The role of IgG4 in the physiopathology of idiopathic membranous nephropathy: state of the art

Nefropatia membranosa idiopática é uma causa de síndrome nefrótica cuja etiopatogenia não está completamente esclarecida. Trata-se de uma doença imunologicamente mediada, na qual a deposição de imunocomplexos decorre da reação antígenoanticorpo in situ, na região subepitelial glomerular. A maioria dos antígenos envolvidos identificados são alvos da IgG4, subclasse predominante em imunofluorescências renais na nefropatia membranosa idiopática, em contraste com as formas secundárias da doença, nas quais IgG1, IgG2 e IgG3 prevalecem. Apesar da IgG4 ser um subtipo de imunoglobulina com baixa capacidade de ativação do complemento, há várias evidências deste envolvimento na glomerulopatia (GMP). Esses dados, em conjunto com achados de depósitos glomerulares de lectina ligadora de manose, um dos principais componentes da via das lectinas do complemento, podem sugerir que tanto a via da lectina como a IgG4 estão envolvidas nesta patologia. Os motivos que desencadeiam a formação dos imunocomplexos e a ativação das vias do complemento nesta doença são incertos. A hipótese mais aceita é a de que a nefropatia membranosa idiopática resulte do conjunto de três condições: presença de proteínas com conformações alteradas que passam a atuar como autoantígenos, anticorpos do tipo IgG4 contra estes antígenos, e susceptibilidade genética. O objetivo foi verificar o possível papel da IgG4 na etiopatogenia da nefropatia membranosa primária segundo o que foi publicado até o momento na base de dados MEDLINE/PubMed, a partir de uma revisão narrativa.

Idiopathic membranous nephropathy is a frequent cause of nephrotic syndrome and its etiopathogenesis is not fully elucidated. In this immune mediated disease, the deposition of immune complexes is the result of an antigen-antibody reaction in situ, in the glomerular subepithelial region. Most of the antigens involved and so far identified are targets of IgG4, a predominant IgG subclass in renal immunofluorescence analysis of idiopathic membranous nephropathy, in contrast with secondary forms of the disease, in which IgG1, IgG2 and IgG3 are prevalent. Even though IgG4 is an immunoglobulin subclass with low complement activation capacity, there is abundant evidence of its involvement in the glomerulopathy. These data, together with findings of glomerular deposition of mannose-binding lectin ­ a major component of the lectin pathway in the complement system ­ may suggest that both the lectin pathway and IgG4 are involved in this pathology. The reasons behind the formation of immune complexes and the activation of complement pathways in this disease are unknown. The most widely accepted hypothesis is that idiopathic membranous nephropathy stems from a combination of three conditions: presence of proteins with altered conformations, which start to act as autoantigens; IgG4 antibodies against these antigens; and genetic susceptibility. The objective of this narrative review was to analyze the possible role of IgG4 in the etiopathogenesis of primary idiopathic membranous nephropathy based on articles published to date in the MEDLINE/PubMed database.

Comparative analysis of primary and secondary glomerulopathies in the northeast of Brazil: data from the Pernambuco Registry of Glomerulopathies - REPEG.

INTRODUCTION: In Brazil, glomerulopathies are the third leading cause of chronic renal disease, accounting for 11% of dialysis patients. Studies on the prevalence of this disease in Northeastern Brazil are scarce. OBJECTIVE: The aim was to describe the findings of biopsies and to conduct a comparative analysis on the clinical laboratory presentation of primary glomerulopathies (PG) and secondary glomerulopathies (SG). METHODS: This was a retrospective study conducted at two public teaching hospitals in the state of Pernambuco, Northeastern Brazil. RESULTS: A total of 1151 biopsies performed between 1998 and 2016 were analyzed. The sample consisted of 670 biopsies of native kidneys, after excluding extra glomerular diseases and unsuitable material. PG were more frequent than SG (58% vs. 42%). There was a prevalence among PG of focal segmental glomerulosclerosis (43%). Membranoproliferative glomerulonephritis and collapsing glomerulopathy, accounted for 9% and 3% of the PG, respectively. For SG, the main etiologies were lupus nephritis (67%) and infections (10%). Female sex, hematuria and an elevated level of creatinine were related to a greater chance of SG, at multivariate analysis. An increase of proteinuria reduced this chance. Nephrotic syndrome was more common among the PG, while urinary abnormalities and nephritic syndrome prevailed in patients with SG. CONCLUSION: This is the first registry of glomerulopathies in Northeastern Brazil. It also presents a comparative analysis of the main clinical laboratory abnormalities of PG and SG, and includes the current classifications of glomerular diseases.

Comparative analysis of primary and secondary glomerulopathies in the northeast of Brazil: data from the Pernambuco Registry of Glomerulopathies - REPEG / Análise comparativa de glomerulopatias primária e secundária no nordeste do Brasil: dados do Registro Pernambucano de Glomerulopatias - REPEG

Abstract Introduction: In Brazil, glomerulopathies are the third leading cause of chronic renal disease, accounting for 11% of dialysis patients. Studies on the prevalence of this disease in Northeastern Brazil are scarce. Objective: The aim was to describe the findings of biopsies and to conduct a comparative analysis on the clinical laboratory presentation of primary glomerulopathies (PG) and secondary glomerulopathies (SG). Methods: This was a retrospective study conducted at two public teaching hospitals in the state of Pernambuco, Northeastern Brazil. Results: A total of 1151 biopsies performed between 1998 and 2016 were analyzed. The sample consisted of 670 biopsies of native kidneys, after excluding extra glomerular diseases and unsuitable material. PG were more frequent than SG (58% vs. 42%). There was a prevalence among PG of focal segmental glomerulosclerosis (43%). Membranoproliferative glomerulonephritis and collapsing glomerulopathy, accounted for 9% and 3% of the PG, respectively. For SG, the main etiologies were lupus nephritis (67%) and infections (10%). Female sex, hematuria and an elevated level of creatinine were related to a greater chance of SG, at multivariate analysis. An increase of proteinuria reduced this chance. Nephrotic syndrome was more common among the PG, while urinary abnormalities and nephritic syndrome prevailed in patients with SG. Conclusion: This is the first registry of glomerulopathies in Northeastern Brazil. It also presents a comparative analysis of the main clinical laboratory abnormalities of PG and SG, and includes the current classifications of glomerular diseases.

Resumo Introdução: No Brasil, glomerulopatias são a terceira causa de doença renal crônica terminal, responsáveis por 11% dos pacientes em diálise. Entretanto, estudos sobre a prevalência desta patologia no nordeste do Brasil são escassos. Objetivo: O objetivo foi descrever os achados das biópsias e analisar comparativamente a apresentação clínico laboratorial entre as glomerulopatias primárias (GP) e as glomerulopatias secundárias (GS). Métodos: Estudo retrospectivo, realizado em dois hospitais públicos de ensino do estado de Pernambuco, nordeste do Brasil. Resultados: Foram avaliadas 1.151 biópsias, de 1998 a 2016. A amostra foi composta por 670 biópsias de rins nativos, após exclusão de patologias extra glomerulares e materiais inadequados. GP foram mais frequentes do que GS (58% × 42%). Dentre as GP, houve predomínio de glomeruloesclerose segmentar e focal (GESF). Glomerulonefrite membranoproliferativa e glomerulopatia colapsante foram responsáveis por 9% e 3% das GP, respectivamente. Das GS, as etiologias principais foram nefrite lúpica (67%) e infecciosas (10%). Sexo feminino, hematúria e nível elevado de creatinina estiveram relacionadas a uma maior chance de GS na análise multivariada. Síndrome nefrótica foi mais comum dentre as GP, já anormalidades urinárias e síndrome nefrítica prevaleceram nos pacientes com GS. Conclusões: Este é o primeiro registro de glomerulopatias do nordeste do Brasil. Demonstrou-se também uma análise comparativa das principais alterações clínico laboratoriais das GP e GS, com classificações atualizadas das doenças glomerulares.