Clinical and histological comparison of IgA nephritis and renal IgA vasculitis.

BACKGROUND: IgA nephritis (IgAN) and renal IgA vasculitis (IgAV) show renal IgA deposits, but whether these two diseases are distinct entities or a spectrum of the same condition is under debate. In this study, we add perspective by contrasting the clinical course and histological presentation using the Oxford classification and the National Institutes of Health lupus nephritis activity index (LN-AI) and chronicity index (LN-CI) in IgAN and IgAV. METHODS: In this single-center, retrospective study, kidney biopsies of 163 adult patients with IgAN and 60 adult patients with IgAV were compared according to the Oxford MEST-C Score, LN-AI, and LN-CI. At the time of biopsy, clinical presentation was compared in terms of age, arterial hypertension, diabetes mellitus, extrarenal manifestations, as well as estimated glomerular filtration rate, proteinuria, and urine sediment. IgAV patients and all IgAN patients with crescents received immunosuppressive treatment. After biopsy, kidney function was followed until patients reached end-stage renal disease (ESRD) or they died. RESULTS: The clinical course and kidney histology differ in IgAN and IgAV. IgAV patients showed more microhematuria and nephritic sediment, while IgAN patients had a greater history of arterial hypertension, more proteinuria, and a higher risk for ESRD. These clinical differences were associated with histological differences, as kidney biopsies of IgAN patients were characterized by glomerulosclerosis and tubular atrophy, while kidney biopsies of IgAV patients were characterized by endocapillary hypercellularity and crescents. Overall, tubular atrophy and a LN-CI ≥ 4 were associated with a higher risk for ESRD in IgAN and IgAV. CONCLUSION: Our study supports the notion that IgAN and IgAV follow distinct courses, suggesting that they require different treatment strategies. Moreover, we make a point that the Oxford classification and LN-CI can be useful in categorizing and predicting long-term prognosis not only in IgAN, but also in IgAV.

Early clinical course of biopsy-proven IgA vasculitis nephritis.

BACKGROUND: IgA vasculitis (IgAV) is the most common form of systemic vasculitis in childhood and frequently involves the kidney. A minority of patients with IgA vasculitis nephritis (IgAVN), especially those presenting with heavy proteinuria and/or kidney failure at onset, are at risk of chronic end-stage kidney disease. For deciding upon treatment intensity, knowledge of the short-term clinical course of IgAVN is needed to improve treatment algorithms. METHODS: For this retrospective multicenter study, the medical records of 66 children with biopsy-proven IgAVN were reviewed. Age, gender, medical history and therapeutic interventions were recorded. Laboratory data included serum creatinine, albumin, urinary protein excretion (UPE) and glomerular filtration rate (eGFR). Threshold values were determined for each parameter, full remission was defined as no proteinuria and eGFR > 90 ml/min/1.73m2. RESULTS: Median age at onset of IgAVN was 8.9 years. 14.1% of the children presented with nephrotic syndrome, 50% had an eGFR below 90 ml/min/1.73 m2 and 51.5% showed cellular crescents in renal histology. The treatment regimens varied notably. Forty-four patients were treated with immunosuppression; 17 patients with crescents or nephrotic syndrome were treated with corticosteroid (CS) pulse therapy. After 6 months, UPE had decreased from 3.7 to 0.3 g/g creatinine and the proportion of patients with a decreased eGFR had fallen from 50.0% to 35.5%. Thirteen children (26.5%) achieved full remission within 6 months. CONCLUSIONS: In most patients with IgAVN proteinuria decreases slowly and kidney function improves, but full remission is reached only in a minority after 6 months. Persistent heavy proteinuria in the first two months rarely developed into long-term proteinuria. Therefore, decisions for more intense treatment should take into account the course of UPE over time. For a comparison of treatment effects, patient numbers were too small. Prospective, randomized controlled trials are necessary to clarify risk factors and the effect of immunosuppressive therapies.

NLRC5: potential novel non-invasive biomarker for predicting and reflecting the progression of IgA nephritis.

BACKGROUND: The nucleotide oligomerization domain-like receptor subfamily C5 (NLRC5) is primarily expressed in the adaptive and innate immune systems. NLRC5 was recently discovered to regulate immunity and inflammatory responses. Abnormal immune and inflammatory responses are considered critical pathogenesis in IgA nephritis (IgAN). However, the role of NLRC5 in IgAN is unknown. We previously showed that NLRC5 can be detected in patients with IgAN; herein, we further examined the pathophysiological significance of NLRC5 in the serum and renal deposits of patients with IgAN. This study is the first to find that NLRC5 is closely correlated with IgAN. METHODS: IgAN patients (n = 50) who were diagnosed by renal biopsy provided blood and renal biopsy tissue, and age-matched healthy control subjects (blood donators n = 22; tissue donators n = 5) were included. Renal biopsies were diagnosed, and blood biochemical parameters were tested. Serum creatinine, urea, proteinuria, haematuria, albumin, and immunoglobulin A levels were recorded. Serum NLRC5 concentrations were detected by enzyme-linked immunosorbent assay, and tissue NLRC5 expression in kidney tissue was detected by immunohistochemical analysis. ROC curve analysis was used to evaluate the diagnostic value of the serum NLRC5 concentration in IgAN. RESULTS: Serum NLRC5 concentration was significantly decreased in the IgAN group compared to that in the healthy control group (P < 0.0001), especially in S1 (Oxford classification) patients (P < 0.0001). Furthermore, serum NLRC5 concentration had a negative correlation with Lee's grade (r = 0.3526, P = 0.0060) and proteinuria levels (r = 0.4571, P = 0.0004). Tissue NLRC5 expression was significantly increased in the IgAN group compared to that in the healthy control group (P < 0.0001); a more significant increase was identified in the S1 group (P < 0.05) and had a positive correlation with Lee's grade (r = 0.497, P < 0.0001). We proposed a cut-off value of 1415 pg/ml for serum NLRC5 concentration, which was able to predict IgAN with 77.27% sensitivity and 87.5% specificity. CONCLUSIONS: Serum NLRC5 concentrations in IgAN are significantly decreased, and tissue NLRC5 expression is significantly increased in IgAN renal tissue, which is consistent with pathological severity. This finding suggests that NLRC5 could potentially be a diagnostic index and represents a prognostic factor in IgAN patients.

Presentation of pediatric Henoch-Schönlein purpura nephritis changes with age and renal histology depends on biopsy timing.

BACKGROUND: This study correlates the clinical presentation of Henoch-Schönlein purpura nephritis (HSPN) with findings on initial renal biopsy. METHODS: Data from 202 pediatric patients enrolled in the HSPN registry of the German Society of Pediatric Nephrology reported by 26 centers between 2008 and 2014 were analyzed. All biopsy reports were re-evaluated for the presence of cellular crescents or chronic pathological lesions (fibrous crescents, glomerular sclerosis, tubular atrophy >5%, and interstitial fibrosis >5%). RESULTS: Patients with HSPN with cellular glomerular crescents were biopsied earlier after onset of nephritis (median 24 vs 36 days, p = 0.04) than those without, whereas patients with chronic lesions were biopsied later (57 vs 19 days, p < 0.001) and were older (10.3 vs 8.6 years, p = 0.01) than those without. Patients biopsied more than 30 days after the onset of HSPN had significantly more chronic lesions (52 vs 22%, p < 0.001), lower eGFR (88 vs 102 ml/min/1.73m2, p = 0.01), but lower proteinuria (2.3 vs 4.5 g/g, p < 0.0001) than patients biopsied earlier. Children above 10 years of age had lower proteinuria (1.98 vs 4.58 g/g, p < 0.001), lower eGFR (86 vs 101 ml/min/1.73m2, p = 0.002) and were biopsied significantly later after onset of nephritis (44 vs 22 days, p < 0.001) showing more chronic lesions (45 vs 30%, p = 0.03). Proteinuria and renal function at presentation decreased with age. CONCLUSIONS: In summary, we find an age-dependent presentation of HSPN with a more insidious onset of non-nephrotic proteinuria, impaired renal function, longer delay to biopsy, and more chronic histopathological lesions in children above the age of 10 years. Thus, HSPN presents more like Immunoglobulin A (IgA) nephritis in older than in younger children.

A novel case of renal pathergy reaction in a Behçet's disease patient complicated by IgA vasculitis.

BACKGROUND: A pathergy reaction is defined as a hyperreactivity of the skin in response to minimal trauma, which is important in the diagnosis of Behçet's disease (BD). However, a pathergy reaction may not be restricted to the skin, and little is known about whether an invasive medical procedure can induce the reaction. Here we present a pathergy reaction induced by renal biopsy, an invasive procedure. CASE PRESENTATION: A 46-year-old man who was diagnosed with IgA vasculitis (IgAV) at the age of 38 was treated with prednisolone and mizoribine. However, complications such as common carotid arteritis or recurrent oral ulcer suggested the possibility of another pathophysiology. Later, increasing urine protein developed, suggesting disease aggravation. However, renal biopsy showed arteriosclerotic changes caused mainly by hypertension, negating exacerbation. After renal biopsy, his renal dysfunction and body temperature fluctuated, and detailed examinations revealed recurrent oral and genital ulcers and a folliculitis-like rash on his scrotum. Later, he complained of myodesopsia caused by hemorrhage in the ocular fundus due to occlusive vasculitis. Complete BD was diagnosed after development of the symptoms, and he was treated with prednisolone and colchicine. CONCLUSION: Co-occurrence of BD with IgAV is very rare and may be associated with immune disorders. Interestingly, a renal biopsy revealed BD, which was masked by the presence of IgAV, and elucidated the etiology of the unexplainable symptoms. To the best of our knowledge, this is the first report of renal pathergy. This case enlightens clinicians to the fact that not only a needle stimulation but also an invasive procedure can cause a pathergy reaction.

Increased risk of renal biopsy complications in patients with IgA-nephritis.

BACKGROUND: The aim of this study was to investigate if specific clinical and histological findings can be related to biopsy complications to enable more closely monitoring patients at high risk. METHODS: Results from 1081 biopsies (994 patients, median age 54.5 years; 896 native and 185 transplant kidney biopsies) were included. Diagnostic quality, morphology, clinical data and complications were prospectively registered. RESULTS: In native kidney biopsies, the most common diagnosis was IgA-nephritis, while in transplant kidney biopsies it was rejection. Patients with IgA-nephritis had a higher risk of major complications (11.7 versus 6.4 %, Odds Ratio (OR) 1.8, Confidence Interval (CI) 1.1-3.2) when compared to patients with other diseases. In native kidney biopsies, patients who experienced major complications had higher degrees of glomerulosclerosis (31 versus 20 %, p = 0.008), whereas in transplant kidney biopsies, patients had higher degrees of interstitial fibrosis (82 versus 33 %, p < 0.001) when compared to patients without major complications. IgA-nephritis-patients had a higher risk of re-biopsies (4.7 versus 1.3 %, OR 4, CI 1.5-11) than patients with other diseases. Patients with native kidneys who needed re-biopsies were younger (42.6 versus 52.3 years, p = 0.031) and had a higher degree of interstitial fibrosis (63 versus 34 %, p = 0.046). CONCLUSIONS: Patients with IgA-nephritis have an increased risk of major biopsy complications. The risk of re-biopsies was higher in younger individuals and in patients with IgA-nephritis.

[Immunoglobulin A vasculitis]. / Immunglobulin-A-Vaskulitis.

The immune-mediated small vessel vasculitis is known as Schoenlein-Henoch purpura predominantly from pediatrics and in these cases occurs more frequently after infections of the upper airways. In adults, immunoglobulin A (IgA) vasculitis often proceeds more severely und recurrently with the classical tetrad of skin manifestations in the sense of leukocytoclastic vasculitis, joint affection, gastrointestinal involvement and IgA nephritis, in contrast to the mostly mild and self-limiting course in children. The background of this systemic vasculitis with formation of IgA immune complexes is considered to be an altered glycosylation of IgA, as this causes the exposure of binding sites for autoantibodies so that an immune complex reaction can be elicited. This ultimately leads to perivascular deposition of IgA and a further activation of neutrophils. Groundbreaking in the diagnostics is the histological detection of leukocytoclastic vasculitis and in cases of renal manifestations a kidney biopsy with characteristic deposits of immune complexes, which cannot be clearly differentiated from IgA nephropathy. The treatment is aimed at the respective manifestation and is mostly based on consensus recommendations due to the lack of randomized studies. In addition to immunosuppressive medication, in the presence of a chronic kidney disease general nephroprotection is becoming increasingly more important also by inhibition of sodium-glucose transporter 2 (SGLT2). The type and extent of kidney involvement and also rare cardiac manifestations are the main determinants of the prognosis. Continuous medical accompaniment of those affected is necessary due to the possible progression of the disease and the risk of recurrence.

First Onset of IgA Vasculitis and Nephritis Following COVID-19 Vaccination.

The article presents a case of a 32-year-old male who developed IgA vasculitis (IgAV) and IgA vasculitis nephritis (IgAVN) after receiving the second dose of the AstraZeneca COVID-19 vaccine. IgAVN can be a rare side effect of COVID-19 vaccines. Healthcare providers should be aware of this potential adverse event, and promptly recognize and manage it. However, the benefits of vaccination in reducing the morbidity and mortality associated with COVID-19 far outweigh the risks of this rare adverse event.

Adult-Onset Immunoglobulin A Vasculitis With Renal Involvement.

A 50-year-old male presented with worsening bilateral lower extremities swelling for a month, associated with a purpuric rash over bilateral upper and lower extremities, joint pain over bilateral hands and ankles, and intermittent generalized abdominal pain. Physical examination was notable for pitting edema in bilateral lower extremities and palpable, non-blanching purpuric rashes and crusts, joint tenderness over bilateral hands/wrists/ankles, and mild generalized abdominal tenderness. Laboratory tests were remarkable for sub-nephrotic range proteinuria and microscopic hematuria. The skin biopsy revealed leukocytoclastic vasculitis. Renal biopsy showed mild mesangial expansion and immunoglobulin A (IgA)-dominant mesangial deposits. The patient was diagnosed with IgA vasculitis (IgAV) nephritis (IgAVN) and was subsequently treated with oral prednisone 80 mg daily for seven days followed by slow tapering doses, oral lisinopril 2.5 mg daily, and oral furosemide 40 mg daily. At the one-month follow-up as an outpatient, his skin rash and lower extremity swelling had resolved along with an improvement of proteinuria.

Terminal Ileitis as the Presenting Feature of Henoch-Schönlein Purpura in a 22-Year-Old Male.

Henoch-Schönlein purpura (HSP) is a self-limited vasculitis that affects children and the preadolescent population. It is characterized by the deposition of immunoglobulin A immune complexes in tissues leading to palpable purpura, abdominal pain, arthritis, and nephropathy. When it occurs in adults, the clinical manifestations are the same; however, adults present with more significant renal involvement. While abdominal pain is the most common gastrointestinal (GI) manifestation, it can also present with GI bleeding, intussusception, bowel ischemia, and bowel perforation. Here, we report the case of a 22-year-old gentleman who presented with nonspecific GI complaints such as nausea, vomiting, and loose stools. He was later found to have terminal ileitis preceding the onset of rash, the biopsy of which confirmed HSP. Terminal ileitis is a rare GI manifestation of HSP and is not very commonly reported in the literature.

Measurement of galactosyl-deficient IgA1 by the monoclonal antibody KM55 contributes to predicting patients with IgA nephropathy with high risk of long-term progression.

BACKGROUND AND OBJECTIVE: About 25% of patients with IgA nephropathy (IgAN) progress to stage 5 chronic kidney disease (CKD) after years of evolution. Various tools have been developed in recent years designed to predict which of the patients will had poorer outcomes. The value of circulating galactosyl-deficient IgA1 (Gd-IgA1) has been related to a worse evolution of IgAN in several studies. There are also some publications that relate higher APRIL values with a worse evolution. Recently, a new method has been developed that allows measuring the value of circulating Gd-IgA1 in a simpler way than those previously available. The objective of this study is to analyze the influence of circulating Gd-IgA1, measured by this method, on the progression of IgAN. MATERIALS AND METHODS: Forty-nine patients with a diagnosis of IgAN demonstrated by renal biopsy were selected in our center, without having received prior immunosuppressive treatment, for whom frozen serum was available. The median follow-up was 4 years. Gd-IgA1 was measured by lectin-independent ELISA with the monoclonal antibody KM55 (IgA1 kit Cat. No. 30111694. IBL Int., Hamburg, Germany). Likewise, APRIL levels were also measured in these patients. RESULTS: 19 (38.8%) patients reached stage 5 CKD. The fourth quartile of circulating Gd-IgA1 was related to a higher cumulative risk of reaching stage 5 CKD in the Kaplan-Meier analysis (risk at the 5th year 39.4% vs. 24.3%, log rank p=0.019). The Gd-IgA1 value was related to an increased risk of CKD stage 5 (HR 1.147, 95% CI 1.035-1.270, p=0.009), regardless of glomerular filtration rate, proteinuria, the percentage of sclerosed glomeruli and the value of segmental sclerosis. We did not find significant differences in the APRIL values. CONCLUSIONS: The value of circulating Gd-IgA1 measured by the monoclonal antibody KM55 is related to a worse evolution of patients with IgAN independently of other variables, so it could be included in the study of patients to improve the prediction of the risk of disease progression.

[Measurement of galactosyl-deficient IgA1 by the monoclonal antibody KM55 contributes to predicting patients with IgA nephropathy with high risk of long-term progression]. / La determinación de IgA1 galactosil deficiente mediante el anticuerpo monoclonal KM55 contribuye a predecir a los pacientes con nefropatía IgA con alto riesgo de progresión a largo plazo.

BACKGROUND AND OBJECTIVE: About 25% of patients with IgA nephropathy (IgAN) progress to stage 5 chronic kidney disease (CKD) after years of evolution. Various tools have been developed in recent years designed to predict which of the patients will had poorer outcomes. The value of circulating galactosyl-deficient IgA1 (Gd-IgA1) has been related to a worse evolution of IgAN in several studies. There are also some publications that relate higher APRIL values with a worse evolution. Recently, a new method has been developed that allows measuring the value of circulating Gd-IgA1 in a simpler way than those previously available. The objective of this study is to analyze the influence of circulating Gd-IgA1, measured by this method, on the progression of IgAN. MATERIALS AND METHODS: Forty-nine patients with a diagnosis of IgAN demonstrated by renal biopsy were selected in our center, without having received prior immunosuppressive treatment, for whom frozen serum was available. The median follow-up was 4 years. Gd-IgA1 was measured by lectin-independent ELISA with the monoclonal antibody KM55 (IgA1 kit Cat. No. 30111694. IBL Int., Hamburg, Germany). Likewise, APRIL levels were also measured in these patients. RESULTS: 19 (38.8%) patients reached stage 5 CKD. The fourth quartile of circulating Gd-IgA1 was related to a higher cumulative risk of reaching stage 5 CKD in the Kaplan-Meier analysis (risk at the 5th year 39.4% vs. 24.3%, log rank p=0.019). The Gd-IgA1 value was related to an increased risk of CKD stage 5 (HR 1.147, 95% CI 1.035-1.270, p=0.009), regardless of glomerular filtration rate, proteinuria, the percentage of sclerosed glomeruli and the value of segmental sclerosis. We did not find significant differences in the APRIL values. CONCLUSIONS: The value of circulating Gd-IgA1 measured by the monoclonal antibody KM55 is related to a worse evolution of patients with IgAN independently of other variables, so it could be included in the study of patients to improve the prediction of the risk of disease progression.

Tonsillectomy Improved Therapeutic Response in Anti-SRP Myopathy With Chronic Tonsillitis.

Chronic tonsillitis has been attracted attention as a source of abnormal immune responses and a possible trigger of autoimmune diseases such as IgA nephritis, IgA vasculitis, palmoplantar pustulosis, psoriasis, rheumatoid arthritis, Behçet's disease, and myositis. Here we present the first report of anti-signal recognition particle antibody-associated necrotizing myopathy (anti-SRP myopathy) with IgA nephropathy and chronic tonsillitis in which the therapeutic response to intravenous immunoglobulin (IVIG) treatment was dramatically improved after tonsillectomy and accompanied by a rapid increase in ΔIgG, defined as the change in serum IgG levels 2 weeks after the start of IVIG treatment relative to pre-treatment levels. Moreover, serum anti-SRP antibody titers became undetectable after tonsillectomy even though the resected tonsils did not produce anti-SRP antibodies. Tonsillectomy should be considered when chronic tonsillitis is observed in patients with autoimmune diseases showing poor response to treatment, including anti-SRP myopathy.

A Global Evolutionary Trend of the Frequency of Primary Glomerulonephritis over the Past Four Decades.

OBJECTIVE: The pattern of glomerulonephritis (GN) in Singapore is compared with that of 19 other countries to review changing trends in the evolution of GN in Asian, Eastern, and Western countries. METHOD: Three thousand two hundred and eighty-nine renal biopsies in Singapore were reviewed and compared with that of 19 other countries. RESULTS: IgA nephritis is on the decline in many countries, including Singapore, though it still remains the commonest GN in Singapore. Membranous GN that if used to be more frequently present in Western countries has also declined though it continues a rising trend in countries such as Singapore and China. Worldwide, the frequency of focal sclerosing glomerulosclerosis (FSGS) continues to increase in many countries, but in some countries, the frequency is still low with mesangiocapillary GN remaining indigenous. CONCLUSION: Urbanization and socioeconomic changes and less exposure to parasitic and other infestations have transformed Singapore's pattern, which is tending toward that of more developed countries. Antigenic exposure due to lifestyle changes, environmental, and industrial pollution are significant contributory factors that affect the evolutionary trend of GN in many countries. The rising trend in the frequency of FSGS may reflect aging and obesity.

[Cough has Many Faces]. / Husten hat viele Gesichter.

We report about a 35 year old previously apparently healthy male patient with terminal chronic renal failure due to IgA nephropathy. The initial symptoms were similar to those of a banal viral respiratory infection. Massive hypertension, orthopnea, edema and blurred vision finally led to the diagnosis of an end stage renal disease. In the renal biopsy the final stage of IgA nephropathy was detected with mostly deserted glomeruli. Hemodialysis was necessary. Among it the patient is well according to the circumstances. He is waiting for a renal transplant.

Use of eculizumab in crescentic IgA nephropathy: proof of principle and conundrum?

IgA nephropathy (IgAN) is characterized by a variable clinical course and multifaceted pathophysiology. There is substantial evidence to suggest that complement activation plays a pivotal role in the pathogenesis of the disease. Therefore, complement inhibition using the humanized anti-C5 monoclonal antibody eculizumab could be a rational treatment. We report here a 16-year-old male with the vasculitic form of IgAN who failed to respond to aggressive conventional therapy including high-dose steroids, cyclophosphamide and plasma exchange and who was treated with four weekly doses of 900 mg eculizumab followed by a single dose of 1200 mg. He responded rapidly to this treatment and has had a stable creatinine around 150 µmol/L (1.67 mg/dL) for >6 months. However, proteinuria was unabated on maximal conventional anti-proteinuric treatment, and a repeat renal biopsy 11 months after presentation revealed severe chronic changes. We believe this case provides proof of principle that complement inhibition may be beneficial in IgAN but also that development of chronicity may be independent of complement.