Chronic Glomerulonephritis

Chronic GlomerulonephritisChronic glomerulonephritis is a kidney disorder caused by slow, cumulative damage and scarring, usually by inflammation, of the tiny blood filters in the kidneys. These filters, known as glomeruli, remove waste products from the blood. Inflammation typically results in one or both of the nephrotic or nephritic syndromes.

Chronic GlomerulonephritisNearly all forms of acute glomerulonephritis have a tendency to progress to chronic glomerulonephritis. The condition is characterized by irreversible and progressive glomerular and tubulointerstitial fibrosis, ultimately leading to a reduction in the glomerular filtration rate (GFR) and retention of uremic toxins.

NKF GuidelinesThe National Kidney Foundation (NKF) defines CKD on the basis of:

Evidence of kidney damage based on abnormal urinalysis results (proteinuria or hematuria) or structural abnormalities observed on ultrasound images

A GFR of less than 60 mL/min for 3 or more months

NKF GuidelinesClassification of the renal disease progression:

Stage 1 – This stage is characterized by kidney damage with a normal GFR (≥ 90 mL/min)Diagnosis + treatment + slowing of the progress of the disease + reduction of cardiovascular disease risks

NKF Guidelines

Stage 2 – This stage is characterized by kidney damage with a mild decrease in the GFR (60-90 mL/min)Estimation of the progression of kidney disease

NKF Guidelines

Stage 3 – This stage is characterized by a moderately decreased GFR (to 30-59 mL/min)Evaluation + treatment of complications

NKF Guidelines

Stage 4 – This stage is characterized by a severe decrease in the GFR (to 15-29 mL/min) Preparation for renal replacement therapy

NKF Guidelines

Stage 5 – This stage is characterized by kidney failureKidney replacement if the patient is uremic

If not treated Chronic Kidney Disease (CKD) End-Stage Renal Disease (ESRD) Cardiovascular Disease Renal Failure Death

Cause The specific cause of most cases of chronic

glomerulonephritis is unknown. Viral infections, such as hepatitis B or C and

acquired immunodeficiency syndrome (AIDS), may lead to chronic glomerulonephritis.

Autoimmune disorders, such as systemic lupus erythematosus, or other causes of vasculitis (inflammation of small blood vessels) may cause chronic glomerulonephritis.

Acute glomerulonephritis may, after a symptom-less period of many years, reappear as chronic glomerulonephritis.

PathophysiologyThe majority of the glomeruli are affected. Depending on the stage of the disease, they may present different degrees of hyalinization. The hyaline is an amorphous material, pink, homogenous, resulted from combination of plasma proteins, increased mesangial matrix and collagen. Totally hyalinised glomeruli are atrophic (smaller), lacking capillaries, hence these glomeruli are non functional.

PathophysiologyFew glomeruli may still present changes which permit to discern the etiology of chronic glomerulonephritis. Obstruction of blood flow will produce secondary tubular atrophy, interstitial fibrosis and thickening of the arterial wall by hyaline deposits. In the interstitium is present an abundant inflammatory infiltrate (mostly with lymphocytes).

Pathophysiology

Symptoms Specific symptoms include:

Blood in the urine (dark, rust-colored, or brown urine) Foamy urine Facial puffiness in the morning Swelling of the legs or ankles or other parts of the

body, due to fluid accumulation (edema) Shortness of breath during exertion due to anemia

Chronic kidney failure symptoms that gradually develop may include the following:

Decreased alertness Drowsiness, somnolence, lethargy Confusion, delirium Coma

Symptoms Decreased sensation in the hands, feet, or

other areas Decreased urine output Easy bruising or bleeding Fatigue Frequent hiccups General ill feeling (malaise) Generalized itching Headache Increased skin pigmentation -- skin may

appear yellow or brown

Symptoms Muscle cramps Muscle twitching Nausea and vomiting Need to urinate at night Seizures Unintentional weight loss

Additional symptoms that may be associated with this disease:

Blood in the vomit or stools Excessive urination High blood pressure Nosebleed

Physical examination Hypertension Jugular venous distention (if severe volume

overload is present) Pulmonary rales (if pulmonary edema is

present) Pericardial friction rub in pericarditis Tenderness in the epigastric region or blood in

the stool (possible indicators of uremic gastritis or enteropathy)

Decreased sensation and asterixis (indicators of advanced uremia)

Laboratory tests and examinationBecause symptoms develop gradually, the disorder may be discovered when there is an abnormal urinalysis during a routine physical or during an examination for another, unrelated disorder. It may be discovered as a cause of high blood pressure that is difficult to control.Laboratory tests may reveal anemia or show signs of reduced kidney functioning, including azotemia. Later, signs of chronic kidney failure may be apparent, including edema .

Laboratory tests and examinationTests that may be done include:

Chest x-ray Kidney or abdominal CT scan Kidney or abdominal ultrasound IVP Urinalysis

A kidney biopsy may show one of the forms of chronic glomerulonephritis or scarring of the glomeruli.

Laboratory tests and examination Urinalysis:

The presence of dysmorphic red blood cells (RBCs), albumin, or RBC casts suggests glomerulonephritis as the cause of renal failure. Waxy or broad casts are observed in all forms of chronic kidney disease (CKD), including chronic glomerulonephritis. Low urine-specific gravity indicates loss of tubular concentrating ability, an early finding in persons with CKD. 

Laboratory tests and examination Urinary protein excretion:

Urinary protein excretion can be estimated by calculating the protein-to-creatinine ratio on a spot morning urine sample. The ratio of urinary protein concentration (in mg/dL) to urinary creatinine (in mg/dL) reflects 24-hour protein excretion in grams. The estimated creatinine clearance rate is used to assess and monitor the glomerular filtration rate (GFR). The are two formulas available for calculation of the GFR. One is Cockcroft-Gault formula and the other is Modification of Diet in Renal Disease (MDRD) Study formula.

Laboratory tests and examination CBC:

Anemia is a significant finding in patients with some decline in the GFR. Physicians must be aware that anemia can occur even in patients with serum creatinine levels lower than 2 mg/dL. Even severe anemia can occur at low serum creatinine levels. Anemia is the result of marked impairment of erythropoietin production.

Laboratory tests and examination Serum chemistry:

Serum creatinine and urea nitrogen levels are elevated. Impaired excretion of potassium, free water, and acid results in hyperkalemia, hyponatremia, and low serum bicarbonate levels, respectively. Impaired vitamin D-3 production results in hypocalcemia, hyperphosphatemia, and high levels of parathyroid hormone. Low serum albumin levels may be present if uremia interferes with nutrition or if the patient is nephrotic.

Treatment Antihypertensive drugs may be prescribed to reduce high blood

pressure. Diuretics may be prescribed to reduce excess fluid retention and

increase urine production. Corticosteroids, immunosuppressives, or other medications may

be used to treat some of the causes of chronic glomerulonephritis. Dietary restrictions like low-protein, low-salt and iron or vitamin

supplements. Steroid medication or immunosuppressive drugs may be

prescribed for some patients. In severe cases where kidney failure occurs, dialysis may be

necessary. Dialysis performs the functions of the kidney by removing waste products and excess fluid from the blood when the kidney cannot (Renal Failure, Chronic).

A kidney transplant is an alternative to dialysis in cases of kidney failure.