- Glomerulopathies may present with isolated hematuria or proteinuria, nephritic syndrome, or nephrotic syndrome. These syndromes may appear as a manifestation of primary glomerular disease or may be associated with systemic diseases, such as diabetes mellitus, amyloidosis, multiple myeloma, SLE, or others.
- The nephritic syndrome is characterized by hematuria, RBC casts, proteinuria, hypertension, edema, and deteriorating renal function.
- The nephrotic syndrome is characterized by proteinuria (>3.5 g/d), hypoalbuminemia, hyperlipidemia, and edema.
- Renal biopsy often provides useful diagnostic, therapeutic, and prognostic information.
- Edema and volume overload can usually be managed with diuretics, as appropriate, and dietary sodium restriction.
- Aggressive treatment of hypertension with a goal BP of <125/75 in most cases has been associated with decreased proteinuria and slower progression of disease.
- Proteinuria should be monitored regularly via use of urinary protein-to-creatinine ratio or urinary microalbumin. A combination of angiotensin-converting enzyme (ACE) inhibitors and angiotensin-receptor blockers (ARBs) is more effective than either agent alone in reducing proteinuria, partially by reducing intraglomerular pressure. Use caution with these agents in patients with accelerating renal failure or a tendency toward hyperkalemia. Serum chemistries, including potassium and Cr, should be monitored within 1-2 weeks of initiation of therapy or an increase in dose.
- Hyperlipidemia in patients with long-standing nephrotic syndrome may increase the risk for atherosclerotic disease. Dietary restriction of cholesterol and saturated fat should be prescribed. HMG-CoA reductase inhibitors are effective in improving the lipoprotein profile, may reduce cardiovascular risk, and may slow progression of renal disease.
- Thromboembolic complications. The nephrotic syndrome produces a hypercoagulable state, and the clinician should maintain a high index of suspicion for thromboemboli. Deep venous thrombosis of the upper and lower extremities, as well as renal vein thrombosis, may occur and should be treated with heparin anticoagulation, followed by long-term warfarin therapy (see Chapter 18, Disorders of Hemostasis and Thrombosis).
- Dietary modifications include modest dietary protein restriction (controversial) and dietary sodium restriction.
- The therapy is most often guided by results of renal biopsy and supplemental laboratory evaluation but frequently involves corticosteroid-based therapy for primarily nephrotic disorders and cytotoxic agents plus corticosteroids for primarily proliferative or nephritic disorders. The use of these agents is rapidly evolving and new immunomodulatory therapeutics are earning indications for glomerular diseases. These agents should be administered only in consultation
- with a nephrologist or other experienced physician with a current knowledge of the literature regarding indications and regimens.
- Initial dosages of cytotoxic drugs are suggested but may require adjustment to keep the WBC count above 3,000-3,500 cells/microliter. WBC counts should initially be checked at least weekly during the administration of cytotoxic agents.