Medical 135

ii. Pulmonary hemorrhage may be severe and life threatening iii. Rapidly progressive renal failure is common iv. Early aggressive treatment may prevent end-stage renal failure

3. Rapidly progressive glomerulonephritis (RPGN)

a. Synonym: crescentic glomerulonephritis b. Clinical feature: rapid progression to severe renal failure in weeks or months c. Occurs in several clinical settings i. Following Goodpasture syndrome ii. Following other forms of glomerulonephritis (post-streptococcal, SLE, Berger disease)

iii. Associated with vasculitis (i.e., Wegner granulomatosis)

iv. Idiopathic d. Light microscopy i. Hypercellular glomeruli ii. Crescent formation in Bowman space e. Immunofluorescence i. Variable ii. May show granular or linear deposits of immunoglobulin and complement f. Electron microscopy i. Variable ii. May or may not have electron-dense deposits iii. GBM disruption and discontinuity is commonly seen g. Prognosis: poor with rapid progression to acute renal failure and end-stage renal disease

4. IgA nephropathy (Berger disease)

a. Clinical features i. Most common cause of glomerulonephritis in the world ii. Common in France, fapan, Italy, and Austria iii. Affects children and young adults (mostiy males)

iv. Recurrent gross hematuria v. Onset may follow a respiratory infection vi. Predominantly nephritic vii. Associated with celiac sprue and Henoch-SchĂ´nlein purpura b. Pathogenesis: The mechanism is unknown. There is a possible entrapment of circulating immune complexes with activation of the alternate complement pathway. There is also a possible genetic predisposition.

c. Light microscopy i. Variable ii. Normal or mesangial proliferation d. Immunofluorescence: mesangial deposits of IgA and C3

e. Electron microscopy: mesangial immune complex deposits f. Prognosis: many cases slowly progress to renal failure over 25 years

5. Membranoproliferative glomerulonephritis (MPGN)

a. Types of MPGN

ii. Type II (dense deposit disease)

b. Clinical features i. May be nephritic, nephrotic, or mixed!

ii. MPGN may be secondary to many systemic disorders (SLE, endocarditis), chronic infections (HBV, HCV, HIV), and malignancies (chronic lymphocytic leukemia)

c. Lab i. Decreased serum C3

ii. C3 nephritic factor (MPGN type II)

d. Light microscopy i. Lobulated appearance of the glomeruli ii. Mesangial proliferation and basement-membrane thickening iii. Splitting of the basement membrane ("tram-tracking") may be seen with a silver or periodic acid-Schiff (PAS) stain e. Immunofluorescence i. Type I: granular pattern of C3 often with IgG, Clq, and C4

ii. Type II: granular and linear pattern of C3 Electron microscopy i. Type I: subendotheUal and mesangial immune complex deposits ii. Type II: dense deposits within the GBM Prognosis i. Slowly progressive course, resulting in chronic renal failure over the course of 10 years ii. High incidence of recurrence in transplants E. Primary Glomerulopathies (Nephrotic)

1. Membranous glomerulonephritis a. Most common cause of nephrotic syndrome in adults b. Etiology i. Most (85%) cases are idiopathic ii. Drugs (penicillamine)

iii. Infections (hepatitis virus B and C, syphilis, etc.)

iv. Systemic diseases (SLE, diabetes mellitus, etc.)

v. Associated with malignant carcinomas of the lung and colon vi. There may be a genetic predisposition c. Light microscopy i. There is a diffuse membrane-like thickening of the capillary walls ii. Basement membrane projections ("spikes") are seen on silver stains d. Immunofluorescence: granular and linear pattern of IgG and C3

e. Electron microscopy i. Subepithelial deposits along the basement membranes ii. Effacement of podocyte foot processes f.

Note

Most patients with MPGN type II disease have an autoantibody called G nephritic factor. This antibody stabilizes G convertase, which leads to enhanced degradation and low serum levels of G.

Note

'Tram-Tracking" This double contour appearance is caused by the splitting of the G8M by extension of the mesangial cell processes into the capillary loop.

KAPLAN^.

medical 137

Note

Focal: only some of the glomeruli are affected

Segmental: only a portion of the glomerular tuft exhibits sclerosis f. Prognosis i. Variable course ii. Spontaneous remission iii. Persistent proteinuria iv. End-stage renal disease

2. Minimal change disease a. Synonyms: lipoid nephrosis, nil disease b. Clinical features j. Most common cause of nephrotic syndrome in children ii. Peak incidence: ages 2-6 years iii. Diagnosis of exclusion c. Light microscopy i. Normal glomeruli ii. Lipid accumulation in proximal tubule cells (lipoid nephrosis)

d. Immunofluorescence: negative; no immune complexes e. Electron microscopy i. Effacement of epithelial (podocyte) foot processes ii. Microvillous transformation iii. No immune complex deposits f. Treatment: corticosteroids g. Prognosis i. Excel] ent ii. Dramatic response to steroids in children iii. Majority have a complete recovery

3. Focal segmental glomerulosclerosis a. Clinical features i. African Americans > Caucasians ii. Occurs in all ages iii. Nephrotic syndrome b. Etiology i. Idiopathic (primary)

ii. Associated with loss of renal tissue iii. Superimposed on other glomerular diseases, such as IgA nephropathy iv. Sickle cell anemia v. Heroin abuse vi. AIDS

vii. Morbid obesity c. Light microscopy i. focal segmental sclerosis and hyalinization of glomeruli ii. Initially affects the glomeruli along the medullary border d. Immunofluorescence: IgM and C3 deposits in the sclerotic segments

Naturally Cure Your Headaches

Naturally Cure Your Headaches

Are Headaches Taking Your Life Hostage and Preventing You From Living to Your Fullest Potential? Are you tired of being given the run around by doctors who tell you that your headaches or migraines are psychological or that they have no cause that can be treated? Are you sick of calling in sick because you woke up with a headache so bad that you can barely think or see straight?

Get My Free Ebook


Post a comment