7.16 Tubulointerstitial Disease

Nonpregnant Pregnant >250 IgG 1000 250

200

500

150 units/mL Abs 405 nm 0 100 1000 IgA Levels of IL-6,

50 Antibody activity,

500 20

20 0 0 0 0 2 02 Nonpregnant Pregnant Nonpregnant Pregnant Time of sampling, wks B C Serum Urine

FIGURE 7-38 (Continued) Petersson and coworkers [12] recently demonstrated that the suscepti- The last may indicate that pregnant women have a generally reduced bility of the pregnant woman to acute UTI is accompanied by reduced level of mucosal inflammation. These factors may be crucial for serum antibody activity (IgG, IgA, IgM), reduced urine antibody activ- explaining the frequency and the severity of acute pyelonephritis ity (IgG, IgA), and low interleukin 6 (IL-6) response, A–C, respectively. during pregnancy. (From Petersson et al. [12]; with permission.)

FIGURE 7-39 Acute prostatitis as visualized sonographically. Acute prostatitis is common after urethral or bladder infection (usually by Escherichia coli or Proteus organisms). Another cause is prostate hematogenous contamination, especially by Staphylococcus. Signs and symptoms of acute prostatitis, in addition to fever, chills, and more generally the signs and symptoms of tissue inva- sion by infection described above, are accompanied by dysuria, pelvic pain, and septic urine. Acute prostatitis is an indication for direct ultrasound (US) examination of the prostate by endorectal probe. In this case of acute prostatitis in a young male, US examination disclosed a prostatic abscess (1) compli- cating acute prostatitis in the right lobe (2). Acute prostatitis is an indication for thorough radiologic imaging of the whole uri- nary tract, giving special attention to the urethra. Urethral stric- ture may favor prostate infection (see Fig. 7-20). Urinary Tract Infection 7.17

Special Forms of Renal Infection

A B

FIGURE 7-40 (see Color Plate) Xanthogranulomatous pyelonephritis (XPN). XPN is a special obstructive renal stone. Nephrectomy was performed. A, The form of chronic renal inflammation caused by an abnormal obstructive renal stone is shown by an arrowhead. The renal immune response to infected obstruction [13]. This case in a cavities are dilated. The xanthogranulomatous tissue (arrows) middle-aged woman with a long history of renal stones is typical. consists of several round, pseudotumoral masses with a typical For several months she complained of flank pain, fever, fatigue, yellowish color due to presence of lipids. In some instances such anorexia and weight loss. Laboratory workup found inflammatory xanthogranulomatous tissue extends across the capsule into the anemia and increased erythrocyte sedimentation rate and C-reactive perirenal fat and fistulizes into nearby viscera such as the colon protein levels. Urinalysis showed pyuria and culture grew Escherichia or duodenum. B, Microscopic view of the xanthogranulomatous coli. CT scan of the right kidney showed replacement of the renal tissue. This part of the lesion is made of lipid structures composed tissue by several rounded, low-density areas and detected an of innumerable clear droplets.

Spectrum of renal malakoplakia

Mononuclear Interstitial Inflammation cells (nonspecific) nephritis

von Hansemann Megalocytic Persistent cells interstitial inflammation (prediagnostic) nephritis Ca2+

Michaelis-Gutmann Defective (MG) bodies Malakoplakia cell function (diagnostic)

B Destuctive granulomas Fibrosis teroid therapy for autoimmune disease. In 13% of the published cases, xanthogranulomatous "pseudosarcoma" malakoplakia involved a transplanted kidney. The female-male ratio is A pyelonephritis 3:1. Lesions can involve the kidney, the bladder, or the ureter and form pseudotumors. B, Histologically, malakoplakia is distinguished by large, pale, periodic acid–Schiff–positive macrophages (von Hanse- FIGURE 7-41 mann cells) containing calcific inclusions (Michaelis-Gutmann bodies). Malakoplakia. Malakoplakia (or malacoplakia), like xanthogranulo- The larger ones are often free in the interstitium. Malakoplakia, an matous pyelonephritis, is also a consequence of abnormal macrophage unusual form of chronic tubulointerstitial nephritis, must be recog- response to gram-negative bacteria, A. Malakoplakia occurs in associ- nized by early renal biopsy and can resolve, provided treatment ation with chronic UTI [14]. In more than 20% of cases, affected per- consisting of antibiotics with intracellular penetration is applied for sons have some evidence of immunosuppression, especially corticos- several weeks. (B, Courtesy of Gary S. Hill, MD.) 7.18 Tubulointerstitial Disease

References

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