CASE 1 (February-March 2006)
A 31-years-old woman was seen by a generalist physician two months ago because she presented macroscopic hematuria, non quantified proteinuria, and "urinary tract infection" (it was not confirmed). After antibiotic treatment hematuria disappeared. There are not any aditional information about this episode.
One month later she present newly macroscopic hematuria, hematic and granulous casts in urine sediment, and proteinuria: 240 mg/24 hours. Creatinine: 1,1 mg/dL; creatinine clearance: 80 mL/min, with urinary volume: 2000 mL. ANAs negative, serum complement levels: normal. Kidneys with normal aspect by ultrasound images. The results of other routine laboratory tests were normal.
She have not previous diseases.
What is your clinical diagnosis?
What is the differential diagnosis?
A renal biopsy was undertaken. See the microphotographies.
Figure 1. (H&E, x400)
Figure 2. (H&E, x400)
Figure 3. (Masson's trichrome, x400)
Figure 4. (Methenamine silver, x400)
Figure 5. (Immunofluorescence using antiserum to C3, X300)
Figure 6. (Immunofluorescence using antiserum to IgA, X400)
Immunofluorescence for IgG, IgM, C1q, kappa, and lambda were negative.
What is your diagnosis?