Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (533 page)

   Hematuria: gross or microscopic. Microscopic hematuria may occur during the initial febrile upper respiratory infection and then reappear with nephritis in 1–2 weeks and lasts for 2–12 months.

   RBC casts and dysmorphic RBCs show glomerular origin of hematuria.

   WBC casts and WBCs show inflammatory nature of the lesion.

   Granular and epithelial cell casts are present.

   Fatty casts and lipid droplets occur several weeks later and are not related to hyperlipidemia.

   Oliguria is frequent.

   Random urinary protein/creatinine ratio is usually between 0.2 and 2 but may occasionally be in the nephrotic range.

   Phenolsulfonphthalein (PSP) excretion is normal in cases of mild to moderate severity and increases with progression of disease. Azotemia with high urine specific gravity and normal PSP excretion usually indicates acute GN.

   
Blood Findings:

   Azotemia is found in approximately 50% of patients.

   Leukocytosis and increased ESR.

   There is mild anemia, especially when edema is present (may be caused by hemodilution, bone marrow depression, or increased destruction of RBCs).

   Serum proteins are normal, or there is nonspecific decrease in albumin and increase in alpha-2 and sometimes beta and gamma regions.