Rapidly Progressive Glomerulonephritis - Etiology, Symptoms, Diagnosis & Treatment

Introduction:

Rapidly Progressing Glomerulonephritis (RPGN) is characterized by a fast loss in kidney function as well as intricate histological characteristics. Unique clinical and pathological symptoms, including a rapid loss of renal function over a brief period, an abnormal urine analysis, and a crescent development in renal biopsies, characterize the condition. To stop future loss of renal function, an early diagnosis is essential. Based on the histology of immune complex deposition, pauci-immune disorders, granular immune complex deposition disorders, and linear antibody deposition, RPGN is categorized. Fibrin precipitate, cellular proliferation, and rupture of the basement membrane are all part of the intricate pathophysiology of RPGN. Due to the complex nature of RPGN, primary care physicians, nephrologists, intensive care nurses, and chemists must work together.

What Is the Etiology of Rapidly Progressive Glomerulonephritis?

Based on immunological complex deposition and histopathology, RPGN is broadly categorized as follows:

1. Anti-Glomerular Basement Membrane Disease:

IgG antibodies in circulation target the noncollagenous portion of the α-3 chain of type IV collagen, an antigen often found in the alveolar basement membrane and anti-glomerular basement membrane illness (GBM). Roughly ten percent to 15 percent of cases of diffuse crescentic glomerulonephritis have the deposits.

Typical characteristics include the following:

• Renal restricted form of crescentic glomerulonephritis.
• Goodpasture syndrome is the term used to describe the combination of crescent-shaped glomerulonephritis with pulmonary hemorrhage.
• The term "dual antibody disease" or "double positive" refers to a condition in which a patient has both crescentic glomerulonephritis and is positive for both anti-neutrophil cytoplasmic antibody (ANCA) and anti-GBM antibody. According to some literature, ten percent to 50 percent of patients with anti-GBM disease also have detectable ANCA (which typically recognizes myeloperoxidase [MPO]), and up to ten percent of patients with ANCA also have circulating anti-GBM antibodies.

2. Granular Immune Complex Disorder:

It may be secondary to the following or idiopathic

• Particularly following a Streptococcus infection, postinfectious GN.

• Illness caused by collagen vascularization.

• Lupus nephritis (nephritis from lupus).

• Henoch-Schönlein purpura, which is accompanied by systemic vasculitis and immunoglobulin A deposition.

• Anti-globulin is a renal disease devoid of vasculitis.

• Cryoglobulinemia mixed.

• Glomerulonephritis due to membrane proliferation.

• Gum disease is caused by fibrillation.

• Idiopathic.

• Approximately 80 percent to 90 percent of instances of pauci-immune disease have positive ANCA results.

• Wegener granulomatosis, also known as granulomatosis with polyangiitis.

• Microscopic polyangiitis (MPA).

• Churg-Strauss syndrome, also known as eosinophilic granulomatosis with polyangiitis (EGPA).

3. Medication Linked to Systemic or Limited Glomerulonephritis:

• Hydralazine.

• Cocaine tainted by Levamisole.

• Methimazole with Propylthiouracil.

• Allopurinol.

• Sulfasalazine.

• Minocycline.

• Penicillamine.

• Rifampicin.

• Aminoguanidine.

• Sofosbuvir.

• Anti-TNF-α treatment for ankylosing spondylitis and rheumatoid arthritis.

3. Crescentic Glomerulonephritis and Idiopathic Pauci-Immune Necrotizing Arthritis:

In about five to ten percent of the cases, the distinguishing characteristics include negative anti-GBM antibodies and negative ANCA.

What Are the Signs and Symptoms of Rapidly Progressive Glomerulonephritis?

The following conditions are referred to as rapidly progressive glomerulonephritis (RPGN), a clinical and pathological syndrome:

• Decrease of renal function that occurs quickly over days to weeks.

• Proteinuria, microscopic or macroscopic hematuria, dysmorphic red blood cells (RBCs), and RBC casts are all indicative of nephrotic urine.

• The cellular crescent development in the glomeruli, a proliferative cellular response observed beyond the glomerular tuft within the Bowman capsule and named crescentic glomerulonephritis due to its crescentic shape, is a histopathological hallmark of the renal biopsy findings.

For diagnosis and treatment, early detection is crucial to stop further loss of renal function. Based on immunological complex deposition and histopathology, RPGN is broadly categorized as follows:

• Antibody deposition in a linear fashion.

• Diseases caused by granular immune complex deposition.

• Disorders classified as pauci-immune (lack of deposition).

How Is Rapidly Progressive Glomerulonephritis Diagnosed?

The laboratory test for the primary causes of RPGN supports the clinical suspicion detailed in the history and presentation section.

• Urinalysis, Urine Protein, and Creatinine Ratio: The dysmorphic red blood cell features of glomerular hematuria can be further identified by microscopic inspection. Proteinuria may indicate either nephrotic range or sub-nephrotic proteinuria.

• Aberrant potassium, magnesium, and calcium electrolyte levels with elevated serum creatinine.

• Differential CBC: Polyangiitis and eosinophilic granulomatosis are correlated with eosinophilia (EGPA).

• Anti-GBM antibody serology using western blot or ELISA.

• ANCA Test: P-ANCA or C-ANCA were the results of the qualitative assay used in the previous test, which used indirect immunofluorescence.

• Using Serology to Identify Post-infections: HIV, hepatitis B, and C serology, and antistreptolysin titer for post-Streptococcus infection are among the serologies used to rule post-infections.

• To Diagnose Post-infection C3 and C4 Levels Using Serology: Some granular immune complex illnesses, such as cryoglobulinemia, lupus, and primary membranoproliferative glomerulonephritis, which cause RPGN, may have a low level of this.

• Lupus serology includes ds DNA, anti-Smith, and anti-nuclear antibody.

• When cryoglobulinemia is suspected, rheumatoid factor and cryoglobulin level are relevant.

• Chest CT scan, chest x-ray, or search for a cavitary lesion in the event of vasculitis if there is a suspicion of diffuse alveolar hemorrhage.

• Bronchoscopy if diffuse alveolar hemorrhage is suspected.

• Skin biopsy or otolaryngologic assessment and biopsy for vasculitis.

• Renal biopsy histological diagnosis is the cornerstone of the conclusive diagnosis.

• Additional harmful antibodies in ANCA-associated disorder: two novel antibodies linked to ANCA disease have been discovered:

  • Lysosome-associated membrane protein-2, or LAMP-2, is an antibody that activates neutrophils and directly damages endothelium.

  • Anti-plasminogen antibodies are correlated with both venous thromboembolic events.

• LDH, platelet, reticulocyte, blood film, and anticardiolipin antibody tests are further measures to rule out conditions that mimic RPGN, such as thrombotic thrombocytopenic purpura (TTP).

What Are the Treatments Available for Rapidly Progressive Glomerulonephritis?

1. Pauci-Immune Crescentic Glomerulonephritis With ANCA Positive Status:

• An oral Prednisone dose after receiving a Methylprednisolone IV dose.

• IV or PO Rituximab and/or Cyclophosphamide.

• The use of plasmapheresis.

• Therapy will last for three or four months.

• Therapy must be continued.

2. Anti-GBM Disease:

• Combining immunosuppressive medications with plasmapheresis is the chosen course of treatment. Preventing increasing renal failure requires starting treatment as soon as feasible. Thus yet, there is no indication that plasmapheresis is beneficial. Though most data from the plasmapheresis era have demonstrated decreased morbidity and mortality compared to the older research, most nephrologists still see it as the preferred option. Another reason could be that plasmapheresis allows for the quick elimination of dangerous antibodies compared to immunosuppressive therapy alone.

3. Glomerulonephritis With an Immune Complex:

• Treatment for related conditions (such as IgA glomerulonephritis, lupus nephritis, cryoglobulinemia, etc.) should be based on their etiology. In most cases, post-streptococcal glomerulonephritis resolves on its own. Glucocorticoids are very infrequently recommended for highly crescentic RPGN.

4. Medications Linked to Glomerulonephritis:

• When the medicine is stopped, the problem normally goes away on its own, but in certain cases, as previously indicated, therapy for pauci-immune glomerulonephritis is required.

5. Antibody With Two Positives:

• This is identical to pauci-immune glomerulonephritis; however, it is necessary to incorporate plasmapheresis.

What Are the Complications?

One can categorize the problems into those linked to the disease and those related to the treatment.

Problems Associated with Illness:

• Particularly, pulmonary hemorrhage is observed in anti-GBM illness.

• ANCA glomerulonephritis is linked to the involvement of the upper and lower respiratory systems.

• Different immune complex deposition glomerulonephritis can cause extrarenal symptoms, such as skin lesions, serositis, and cerebritis in situations of lupus nephritis.

Problems Associated with Treatment:

The main side effects of immunosuppressive treatment are a variety of opportunistic infections, some of which can be fatal. Particular side effects of Cyclophosphamide include hematuria and cystitis. Because plasmapheresis involves the removal of clotting factors, the patient is more vulnerable to the consequences of bleeding.

Conclusion:

For the past two decades, immunopathologic studies have shown that glomerular deposition of anti-GBM antibodies, immune complexes, or an as-yet-unidentified mechanism that does not include glomerular antibody deposition can all cause rapidly progressive glomerulonephritis (RPGN). Reminiscent of small vessel vasculitis, the latter process might be cell-mediated. It is not common for pathogenic glomerular immunoglobulin deposition to accompany idiopathic RPGN patients. Both a rapid decline in kidney function and complex histological features are hallmarks of rapidly progressing glomerulonephritis (RPGN). Distinct clinical and pathological signs, such as an abrupt loss of renal function, abnormal urine analysis, and crescent development in renal biopsies, characterize the disorder. An early diagnosis is crucial to prevent further loss of renal function.