Efficacy of Corticosteroids in Infection-Related Glomerulonephritis–A Randomized Controlled Trial

The Pulsing Paradox: Successful Steroid Therapy in Infection-Related Glomerulonephritis

The patterns of infection-related glomerulonephritis (IRGN) are rapidly changing in terms of age at presentation and sources of infection. The existing literature on the use of steroids in IRGN is inconsistent. A diabetic male in his sixties presented with features of anasarca, bilateral flank pain, and acute pulmonary edema. He had a non-healing ulcer over his right leg, with pus culture showing growth of methicillin-resistant Staphylococcus aureus (MRSA). Computed tomography (CT) of the kidneys, ureter, and bladder (KUB) showed features of bilateral pyelonephritis. The patient went on to develop acute renal failure and eventually required hemodialysis. A renal biopsy was performed, and features of IRGN with crescents were noted. Considering the presence of crescents in renal biopsy, a trial of steroids was given under antibiotic cover, which resulted in a near-complete resolution of renal failure.

Infection-Associated Glomerulonephritis

The nephritic syndrome has been associated with a wide variety of infections, spanning many organisms and myriad clinical presentations. Infection-associated glomerulonephritis is challenging to diagnose given the many confounding factors linking kidney injury to infection; however, urine microscopy can assist in identifying abnormal cellular elements suggestive of glomerulonephritis. Kidney biopsy remains the gold standard for diagnosing the underlying pathologic lesion. Treatment of infection-associated glomerulonephritis centers around aggressive and complete treatment of the underlying infectious driver. It is often hard to know exactly when immunosuppression may be required in addition to treating the infection.

Glomerulonephritis and Septic Pulmonary Embolism: A Rare but Life-Threatening Complication of Permanent Pacemaker Implantation

Infection-related glomerulonephritis (IRGN) is an immunologically mediated glomerular injury triggered by an extrarenal infection. Infective endocarditis-associated glomerular nephritis is an entity caused by infection of the cardiac valves. IRGN is most common in children, and post-streptococcal glomerulonephritis (PSGN) is commonest in the age group of 2-14 years. In contrast to childhood PSGN and epidemic PSGN, which usually resolve completely with antibiotics, IRGN in adults has a guarded prognosis. Cardiovascular implantable electronic device-associated infective endocarditis (CIED-IE) is a phenomenon for which the incidence is on the rise (0.1-5.1%). The most frequent CIED-IE pathogens were staphylococci or other Gram-positive bacteria. CIED-IE poses difficult management problems for the clinician. We present the case of a 50-year-old patient with a pacemaker who was found to have infective endocarditis and septic embolism.

The five types of glomerulonephritis classified by pathogenesis, activity and chronicity (GN-AC)

Glomerulonephritis (GN) is a diverse group of immune-mediated disorders. Currently, GN is classified largely by histological patterns that are difficult to understand and teach, and most importantly, do not indicate treatment choices. Indeed, altered systemic immunity is the primary pathogenic process and the key therapeutic target in GN. Here, we apply a conceptual framework of immune-mediated disorders to GN guided by immunopathogenesis and hence immunophenotyping: (i) infection-related GN require pathogen identification and control; (ii) autoimmunity-related GN, defined by presence of autoantibodies and (iii) alloimmunity-related GN in transplant recipients both require the suppression of adaptive immunity in lymphoid organs and bone marrow; (iv) autoinflammation-related GN, e.g. inborn errors of immunity diagnosed by genetic testing, requires suppression of single cytokine or complement pathways; and (v) Monoclonal gammopathy-related GN requires B or plasma cell clone-directed therapy. A new GN classification should include disease category, immunological activity to tailor the use of the increasing number of immunomodulatory drugs, and chronicity to trigger standard chronic kidney disease care including the evolving spectrum of cardio-renoprotective drugs. Certain biomarkers allow diagnosis and the assessment of immunological activity and disease chronicity without kidney biopsy. The use of these five GN categories and a therapy-focused GN classification is likely to overcome some of the existing hurdles in GN research, management and teaching by reflecting disease pathogenesis and guiding the therapeutic approach.

IgA-dominant postinfectious glomerulonephritis: a case report

Introduction

Acute postinfectious glomerulonephritis (APIGN) is an immunological glomerular disease that is an important health issue in developing countries. The incidence remains high in developing countries with a male-to-female ratio of 2:1 and age predominantly above 50 years. In this case study, we present a patient with a history of Staphylococcus epidermidis infection, a past medical history of diabetes mellitus, and histopathological findings of APIGN with Immunoglobulin A (IgA) deposition.

Methods

A 58-year-old male presented to the emergency room with a 6-day history of severe low back pain. Three days later, the patient developed fever, chills, abdominal pain in the upper quadrant and a subsequent lower limb cellulitis. Various immunological tests, imaging studies, and kidney biopsy were performed to arrive at a diagnosis.

Results

Following the diagnosis and treatment of Cholangitis and Staphylococcus epidermidis, further investigation led to a diagnosis of IgA-dominant APIGN. IgA-dominant APIGN was treated with antibiotics, renin-angiotensin-aldosterone system inhibitors and steroids, and the patient was discharged from the hospital.

Conclusion

In developing countries, APIGN is a relatively common presentation of kidney damage due to acute kidney injury and nephritic syndrome. IgA-dominant APIGN is a rare but increasingly recognized morphological variant in which IgA is the sole or dominant immunoglobulin. This unique presentation and multidisciplinary approach for diagnosing and treating IgA-dominant APIGN need to be considered and understood by healthcare professionals to better help these patients. Further investigation is needed to understand the best treatment of this IgA-dominant APIGN presentation and its prognosis.

Bacterial infection-related glomerulonephritis in patients with diabetes

AIM

Diabetic patients are prone to infections, thus making them a unique cohort at risk of developing bacterial infection-related glomerulonephritis (IRGN).

METHODS

In total, 1693 adult diabetic patients underwent kidney biopsy between 2005 and 2021 at our tertiary care hospital in South India. Of these, 121 consecutive cases which met criteria of bacterial IRGN were included in this study.

RESULTS

The mean age of the cohort was 53.1 ± 10.1 years and 83/121 (68.5%) were males. Majority (98.3%) had type 2 diabetes for a median duration of 6 (IQR, 2-12) years. The most common sites of infection were skin (47/121, 38.8%) and urinary tract (15/121, 12.4%). Fifty percent (58/121) of patients had underlying advanced diabetic kidney disease (DKD). Isolated C3 deposits (without immunoglobulin) occurred in 66/121 (54.5%) patients predominantly in advanced DKD patients. IgA-dominant glomerulonephritis occurred in only 9/121 (7.4%) patients. Short-course oral steroid was given to 86/121 (71.1%) patients. Steroid related dysglycemia and immunosuppression related infections occurred in 9/61 (14.8%) and 16/61 (26.2%) patients respectively. Of the 90 patients with follow up details >3 months, 46 (51.1%) progressed to kidney failure over a median period of 0.5 (IQR, 0-7.2) months. Patients diagnosed in the latter half of our study period (2013-2021) were older, less commonly presented with fever, had more pronounced hypocomplementemia and severe renal histology predominantly with a 'starry sky' immunofluorescence pattern.

CONCLUSION

Superimposed bacterial IRGN on underlying DKD is associated with poor renal outcomes. Use of short course steroid was associated with significant toxicity.

Infection-Related Glomerulonephritis in Children and Adults

Infection-related glomerulonephritis is an immunologically mediated glomerular injury after an infection. Glomerulonephritis may occur with the infection or after a variable latent period. Poststreptococcal glomerulonephritis (PSGN) is the prototype of infection-related glomerulonephritis. The streptococcal antigens, nephritis-associated plasmin-like receptor and streptococcal exotoxin B, have emerged as major players in the pathogenesis of PSGN. Although PSGN is the most common infection-related glomerulonephritis in children, in adults, glomerulonephritis is secondary to bacteria such as staphylococci, viruses such as hepatitis C, and human immunodeficiency virus, and, rarely, parasitic infections. Supportive therapy is the mainstay of treatment in most infection-related glomerulonephritis. Treatment of the underlying infection with specific antibiotics and antiviral medications is indicated in some infections. Parasitic infections, although rare, may be associated with significant morbidity. Poststreptococcal glomerulonephritis is a self-limiting condition with a good prognosis. However, bacterial, viral, and parasitic infections may be associated with significant morbidity and long-term consequences. Epidemiologic studies are required to assess the global burden of infection-related glomerulonephritis. A better understanding of the pathogenesis of infection-related glomerulonephritis may unravel more treatment options and preventive strategies.

KDOQI US Commentary on the 2021 KDIGO Clinical Practice Guideline for the Management of Glomerular Diseases

The KDIGO 2021 Clinical Practice Guideline for the Management of Glomerular Diseases represents the first update to this set of recommendations since the initial set of KDIGO guideline recommendations was published in 2012. The pace of growth in our molecular understanding of glomerular disease has quickened and a number of newer immunosuppressive and targeted therapies have been introduced since the original set of guideline recommendations, making such an update necessary. Despite these updates, many areas of controversy remain. In addition, further updates since the publication of KDIGO 2021 have occurred which this guideline does not encompass. With this commentary, the KDOQI work group has generated a chapter-by-chapter companion opinion article that provides commentary specific to the implementation of the KDIGO 2021 guideline in the United States.

Glomerulonephritis: immunopathogenesis and immunotherapy

'Glomerulonephritis' (GN) is a term used to describe a group of heterogeneous immune-mediated disorders characterized by inflammation of the filtration units of the kidney (the glomeruli). These disorders are currently classified largely on the basis of histopathological lesion patterns, but these patterns do not align well with their diverse pathological mechanisms and hence do not inform optimal therapy. Instead, we propose grouping GN disorders into five categories according to their immunopathogenesis: infection-related GN, autoimmune GN, alloimmune GN, autoinflammatory GN and monoclonal gammopathy-related GN. This categorization can inform the appropriate treatment; for example, infection control for infection-related GN, suppression of adaptive immunity for autoimmune GN and alloimmune GN, inhibition of single cytokines or complement factors for autoinflammatory GN arising from inborn errors in innate immunity, and plasma cell clone-directed or B cell clone-directed therapy for monoclonal gammopathies. Here we present the immunopathogenesis of GN and immunotherapies in use and in development and discuss how an immunopathogenesis-based GN classification can focus research, and improve patient management and teaching.

Indian TrANslational GlomerulonephrItis BioLogy nEtwork (I-TANGIBLE): Design and Methods

BACKGROUND AND AIM

Primary glomerular disease accounts for one-sixth of all chronic kidney diseases (CKDs) in India. We remain limited in our ability to effectively treat these conditions because of lack of understanding of the disease mechanisms and lack of predictors to identify the clinical course and therapeutic responsiveness. We propose to develop a network of investigators in glomerular diseases, collect information in a systematic fashion to understand the clinical outcomes, answer translational research questions better, and identify and recruit patients for clinical trials.

MATERIALS AND METHODS

This is a prospective, observational study. The Indian TrANslational GlomerulonephrItis BioLogy nEtwork (I-TANGIBLE) cohort will enroll patients (>18 years) with biopsy-proven minimal change disease (MCD), focal segmental glomerulonephritis (FSGS), membranous nephropathy (MN), IgA nephropathy (IgAN), or membranoproliferative glomerulonephritis (MPGN) (immune complex- and complement-mediated), with first biopsy taken within 2 years of enrollment. Patients with estimated glomerular filtration (eGFR) rate <15 ml/min/1.73 m2 for >3 months at the time of screening, kidney transplant or bone marrow transplant recipients, patients with active malignancy, and patients with active hepatitis B/C replication or human immunodeficiency virus (HIV)-I/II will be excluded. Clinical details including history, medication history and details, and family history will be obtained. Consenting patient's blood and urine samples will be collected and stored, aligned to their clinical follow-up.

EXPECTED OUTCOMES

The network will allow accurate ascertainment of disease burden of glomerular diseases across study sites, establishment of the treatment pattern of common glomerular diseases, investigation of medium- and long-term outcomes (remission, relapse, rate of eGFR decline), and building a suitable infrastructure to carry out clinical trials in primary glomerular disease.

The C3 conundrum

A 62-year-old man with nephritic syndrome underwent a kidney biopsy which revealed a C3 dominant pattern on immunofluorescence. A diagnosis of C3 glomerulopathy (C3G) was suspected. However, a recent skin infection and high levels of anti-streptococcal antibodies were indicative of post-infectious glomerulonephritis (PIGN). This paper compares PIGN and C3G and describes an atypical form of PIGN with alternative complement pathway dysregulation.

The Diagnostic Conundrum of Glomerular Crescents With IgA Deposits

INTRODUCTION

Glomerulonephritis (GN) with crescents and IgA deposits in kidney biopsy poses a frequent diagnostic and therapeutic dilemma because of multiple possibilities.

METHODS

Native kidney biopsies showing glomerular IgA deposition and crescents (excluding lupus nephritis) were identified from our biopsy archives between 2010 and 2021. Detailed clinicopathologic features were assessed. One-year clinical follow-up on a subset of cases was obtained.

RESULTS

A total of 285 cases were identified, and these clustered into IgA nephropathy (IgAN, n = 108), Staphylococcus or other infection-associated GN/infection-related GN (SAGN/IRGN, n = 43), and antineutrophil cytoplasmic antibody-associated GN (ANCA-GN, n = 26) based on a constellation of clinicopathologic features, but 101 cases (group X) could not be definitively differentiated. The reasons have been elucidated, most important being atypical combination of clinicopathologic features and lack of definitive evidence of active infection. Follow-up (on 72/101 cases) revealed that clinicians' working diagnosis was IgAN in 43%, SAGN/IRGN in 22%, ANCA-GN in 28%, and others in 7% of the cases, but treatment approach varied from supportive or antibiotics to immunosuppression in each subgroup. Comparing these cases as "received immunosuppression" versus "non-immunosuppression," only 2 features differed, namely C3-dominant staining, and possibility of recent infection (both higher in the no-immunosuppression group) (P < 0.05). Renal loss was higher in the non-immunosuppression subgroup, but not statistically significant (P = 0.11).

CONCLUSION

Diagnostic overlap may remain unresolved in a substantial number of kidney biopsies with glomerular crescents and IgA deposits. A case-by-case approach, appropriate antibiotics if infection is ongoing, and consideration for cautious immunosuppressive treatment for progressive renal dysfunction may be needed for best chance of renal recovery.