Nephritic Syndrome
Nephritic Syndrome
Nephritic Syndrome
Nephritic Syndrome
Hematuria RBC Casts Proteinuria (<3.0 g/day) Decreased GFR Edema Hypertension
Nephrotic Syndrome
Proteinuria (>3.0 g/day) Hypoalbuminemia (<3.0 g/dL) Edema Hyperlipidemia Lipiduria
Deffination Nephritic syndrome is characterized by hematuria, RBC casts in urine sediment mild to moderate proteinuria and hypertension. Its a clinical manifestation of glomerulonephritis. Sometime elevated s. creatinine and BUN, and etiology is wide spectrum of disease leading to glomerulonephritis.
Factors affecting the pathogenesis of glomerular disease: 1. The capacity of the reticuloendothelial system to clear immune complexes from the circulation, 2. The capacity of the glomerulus itself to remove deposited complexes. this is thought to be a function of the glomerular mesangium.
Small complexes, formed in antigen excess, localize on the capillary basement membrane. Larger complexes tend to localize in the mesangium and cause much less glomerular injury.
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Focal and segmental glomerulosclerosis Minimal change disease Membranous nephropathy Diabetic nephropathy Preeclampsia Late PIGN IgA nephropathy Focal and segmental glomerulosclerosis Membranous nephropathy Diabetic nephropathy Minimal change disease IgA nephropathy Amyloidosis (primary) Light chain deposition disease Benign nephrosclerosis Late PIGN
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*More commonly manifests as nephrotic syndrome. PIGN = postinfectious glomerulonephritis; GN = glomerulonephritis, RPGN = rapidly progressive glomerulonephritis Adapted from Rose BD. Pathophysiology of Renal Disease (2nd edition). New York: McGraw-Hill, 1987, p. 167.
Alport's Syndrome:
Hereditary nephritis is a genetically heterogenous disorder characterized by hematuria, impaired renal function, sensorineural deafness, and ocular abnormalities. Cause is a gene mutation affecting type IV collagen. Symptoms and signs are those of nephritic syndrome with sensorineural deafness and, less commonly, those of ophthalmologic diseases. Diagnosis is by family history and urinalysis. Treatment is that of chronic renal failure.
Immunoglobulin A Nephropathy:
IgA nephropathy is deposition of IgA immune complexes in glomeruli, manifesting as slowly progressive hematuria, proteinuria, and, often, renal insufficiency. Diagnosis is based on urinalysis and renal biopsy. Prognosis is generally good. Treatment options include ACE inhibitors, corticosteroids, and -3 polyunsaturated fatty acids.
Mortality/Morbidity:
Early death is extremely rare in children (<1%) but is significantly more common in adults (25%). This is secondary to congestive heart failure and azotemia. Nephrotic-range proteinuria is more common in adults (20%) than in children (4-10%). Approximately 83% of adults have azotemia, compared to 25-40% of children.
Sex:
Clinical cases of APSGN are twice as common in males compared to females.
Age:
This condition typically affects children aged 2-12 years.
Pathophysiology:
Poststreptococcal glomerulonephritis follows infection with only certain strains of streptococci designated as nephritogenic. The offending organisms are virtually always group A streptococci. Acute poststreptococcal glomerulonephritis (APSGN) APSGN is an immune complex disorder, antigen-antibody interaction is containing a streptococcal antigen, which is deposited in the affected glomeruli. The size of glomerular basement membrane (GBM) pores and the molecular size of the streptococcus-Ig complex are also important determinants. Therefore, the immune complex molecule can be more easily rodded into the glomerulus in children than in adults and, thus, may explain the increased frequency of ASPGN in children compared to that in adults.
Immunofluorescence
In biopsy samples taken in the first 2-3 weeks of illness, deposits of immunoglobulin G and C3 in a diffuse granular pattern are present along the glomerular capillary wall and mesangium. Immunoglobulin M may be present in small amounts. Significant amounts of IgA suggest an alternative diagnosis. 3 different patterns of immunofluorescence called the garland pattern, the starry sky pattern, and the mesangial pattern.
Electron microscopy
Many of the ultrastructural changes confirm the findings from light microscopy evaluations. The number of endothelial, mesangial, and infiltrating inflammatory cells is increased. The glomerular basement membrane is usually normal in thickness and contour, although occasionally patchy thickening may be noted. Presence of glomerular subepithelial electron-dense immune-type deposits. The deposits are discrete and are commonly found on the part of the glomerular basement membrane overlying the mesangium
CLINICAL FINDINGS
History: A history suggestive of preceding streptococcal infection may include a preceding infective episode such as pharyngitis, tonsillitis, or pyoderma. Latent period:
In general, the latent period is 1-2 weeks after a throat infection and 3-6 weeks after a skin infection. The onset of signs and symptoms at the same time as pharyngitis (also called synpharyngitic nephritis) is more likely to be immunoglobulin A (IgA) nephropathy rather than APSGN.
Nonspecific symptoms
These can include general malaise, weakness, and anorexia and are present in 50% of patients. Approximately 15% of patients complain of nausea and vomiting.
Acute nephritic syndrome presenting as edema, hematuria, and hypertension with or without oliguria is the most frequent presentation of APSGN. Approximately 95% of clinical cases have at least 2 manifestations, and 40% have the full-blown acute nephritic syndrome.
Edema is present in 80-90% of cases, and it is the presenting complaint in 60% of cases. The onset of puffiness of the face or eyelids is sudden. It is usually prominent upon awakening and, if the patient is active, tends to subside at the end of the day. In some cases, generalized edema and other features of circulatory congestion, such as dyspnea, may be present. Edema is a result of a defect in renal excretion of salt and water. The severity of edema is often disproportionate to the degree of renal impairment. Hypertension occurs in 60-80% of cases and is more common among elderly individuals. In 50% of cases, the hypertension can be severe; however, more often it is transient, with normalization of BP upon therapy If hypertension persists, it is more indicative of the progression to a more chronic stage. Plasma renin activity is usually low due to fluid overload. Left ventricular dysfunction This is present in 10-50% of cases, and, in 15%, urine output is less than 200 mL. Oliguria is indicative of the severe crescentic form of the disease. It is often transient, with diuresis occurring within 1-2 weeks. This is present universally. In 30% of cases, gross hematuria is present.
Hypertension
Hematuria
Prognosis: In children, the immediate prognosis is excellent. In elderly patients who have congestive heart failure or azotemia in the early phase, early mortality rates can be as high as 25%. The long-term prognosis is debatable.
Fewer than 1% of children have elevated serum creatinine values after 10-15 years of followup. Adults who develop massive proteinuria often have the garlandlike pattern of immune deposits. Their prognosis is worse; approximately 25% progress to chronic renal failure.
Lab Studies:
Evidence of preceding streptococcal infection Antibody titers to extracellular products of streptococci are positive in more than 95% of patients with pharyngitis and 80% of patients with skin infections. The antistreptolysin (ASO), antinicotinamide adenine dinucleotidase (anti-NAD), antihyaluronidase (AHase), and antiDNAse B are commonly positive after pharyngitis, and antiDNAse B and AHase titers are more often positive following skin infections. ASO titers are frequently used to document streptococcal infection, but a more sensitive test is the streptozyme test, which tests antibodies to ASO, antiDNAse B, AHase, and anti-NAD. Antizymogen titers that are 2 dilutions higher than the mean in healthy controls are reported to have a sensitivity of 88% and a specificity of 85% in the diagnosis of streptococcal infection in patients with glomerulonephritis. The antibody titers are elevated at 1 week, peak at 1 month, and fall toward preinfection levels after several months. Elevated BUN and creatinine could be elevated transient Serologic findings Low serum complement levels universal finding in the acute phase of APSGN. Most patients have marked depression of serum hemolytic component CH50 and serum concentrations of C3. In some patients, the levels of C2 and C4 may also be decreased. In most uncomplicated cases, the complement levels return to normal in 6-8 weeks. Occasionally, low complement levels persist for 3 months. Urinalysis Hematuria and proteinuria are present in all cases. Urine sediment has red blood cells and casts, white blood cells, granular casts, and, rarely, white blood cell casts. Hematuria usually resolves within 3-6 months but may persist as long as 18 months. Approximately 5-10% of patients with APSGN have nephrotic-range proteinuria. Proteinuria usually disappears in 6 months. A mild increase in urinary protein excretion is present in 15% at 3 years and 2% at 10 years.
Imaging Studies:
CXR and KUB are normal. Renal ultrasound images usually reveal normal-sized kidneys bilaterally.
Atypical features in the early phase that suggest the need for renal biopsy include the following:
Absence of the latent period between streptococcal infection and acute glomerulonephritis Anuria Rapidly deteriorating renal function Normal serum complement levels No rise in antistreptococcal antibodies Extrarenal manifestations of systemic disease No improvement or continued decrease in the glomerular filtration rate at 2 weeks Persistence of hypertension beyond 2 weeks
Atypical features in the recovery phase that mandate a renal biopsy include the following:
Failure of glomerular filtration rate to normalize by 4 weeks Persistent hypocomplementemia beyond 6 weeks Persistent microscopic hematuria beyond 18 months Persistent proteinuria beyond 6 months
Management:
Symptomatic therapy:
During the acute phase of the disease, restrict salt and water (Low-salt diet 2g/d) Restricting physical activity is appropriate in the first few days.
Hypertension;
If significant edema or hypertension develops, administer diuretics. Loop diuretics increase urinary output and consequently improve cardiovascular congestion and hypertension. ACEi or CCB. For malignant hypertension, intravenous nitroprusside.
Patients with skin infections must practice good personal hygiene. This is essential. During epidemics, recommend that high-risk individuals, including close contacts and family members, receive empirical prophylactic treatment. Surgical Care: Surgical care is not indicated.
A 21 year-old woman presents with tea-colored urine,three weeks after being evaluated for a sore throat. Physical examination is notable for a blood pressure of 170/100 and 3+ pitting edema. Serum creatinine is 2.1 mg/dl. Urine dipstick demonstrates 2+ protein, large heme and large leukocyte esterase.