Tuesday, January 12, 2010
January 8th - MHH - Glomerulonephritis
Today at Hermann, a case of possible GN was presented in a patient with Hepatitis C. Here is a general overview of Glomerulonephritis:
Patients can present with HTN, Oligemia, Hematuria and peripheral edema. If you see dysmorphic RBCs or RBC Casts, think of a glomerular disorder with a nephritic syndrome component
There are multiple ways to memorize the GNs. I like to think of them as those causing low complement and those with normal complement. The ones with low complement you can think of having a "systemic disease" present versus a more renal-based pathology...
Low Complement - Systemic Diseases
SLE - Think when patient has some of the 11 current diagnostic criteria
Endocarditis - In setting of fever and murmur
Cryoglobulinmenia - Patient with underlying Liver Disease, arthralgias and skin rash
Shunt Nephritis - after insertion of vascular shunt
Cholesterol Emboli Syndrome - Post cath/vascular intervention with toe rash/ischemia and eosinophilia
Low Complement - Renal Causes
1) Post-Infectious - Occurs on average 10-14 days after strept infection (including pharyngitis or impetigo) but other infections can cause PIGN as well. If you want to tell for sure that there is prior infection, you can send ASO titers or anti-DNAse B titers. Complements are low, but for no longer than 2 months. Most patients self-recover, but some go on to need dialysis. Treat the underlying infection.
2) Membranoproliferative - Remember this disease can present with a nephrotic overlap in addition to a GN. There are many underlying "triggers" - but Hepatitis C is the most common. Complements stay low for LIFE - unlike with PIGN where they can return to normal after 2 months. Children are usually given steroids, adults have the underlying condition treated (especially IFN for Hepatitis C) and some are give Aspirin as well.
Normal Complement (i.e. the Pauci-Immune diseases)
1) ANCA-associated and other vasculitis
Wegeners: c-ANCA Positive. Granulomas in the Upper Airway, Lung and Kidneys. Consider in a patient with history of sinusitis or recurrent episodes of otitis media. CXR with Lung nodules, cavities or infiltrates.
Arthritis and purpura are common as well.
Churg-Strauss: - p-ANCA positive. History of allergic rhinits or asthma that is difficult to control. High serum eosinophils. Many patients with have arthralgias and neuropathy.
HSP - Arthralgias, palpable purpura, abdominal pain and renal failure. The debate is out whether or not to give these patients steroids, as most patients recover without treatment.
Microscopic Polyangiitis - p-ANCA Positive. Can present with a multitude of symptoms, and often involves the lung. Many patients have fever, palpable purpura, mononeuritis multiplex and arthralgias.
2) GBM Diseases - Essentially those that attack the basement membrabe of both the kidney and lung together. Goodpastures Syndrome is the one to know. Pulmonary hemorrhage with various degrees of hematuria are key. Send anti-GBM antibodies. Treat with repeated plasmapheresis combined with glucocorticosteroids and cyclophosphamide.
3) IgA Nephropathy - More common in males and Asians. Unlike with PIGN, these patients will have GN immediately after the antecedent viral infection. They can have microscopic or gross hematuria, and even extreme exercise can "trigger" the disease. Patients may need ACEI and Fish Oils.
4) Alports - X-Linked with cochlear disease and lens involvement.
Also remember that any of these nephritic syndromes can become RPGN (i.e crescenteric GN) if the creatinine rapidly rises within days to weeks. Those diseases with ANCA positivity and GBM Syndromes are notorious for causing this to occur. Treat the ANCA disorders (and SLE) with steroids + cyclophosphamide. Treat the Anti-GBM diseases with plasmapheresis, followed by steroids + cyclophospamide.