Chapter 9: Infection-related glomerulonephritis

BACKGROUND AND RATIONALE The prototype for bacterial infection-related GN (also called postinfectious GN) is poststreptococcal GN, which most often occurs in children following a pharyngeal or cutaneous infection (impetigo) caused by a particular nephritogenic strain of Streptococci, and usually has a favorable outcome. However, in the last decades the spectrum of postinfectious GN has changed. The incidence of poststreptococcal GN, particularly in its epidemic form, has progressively declined in industrialized countries. Recent series reported that streptococcal infections accounted for only 28–47% of acute GN, Staphylococcus aureus or Staphylococcus epidermidis being isolated in 12–24% of cases and Gram-negative bacteria in up to 22% of cases. Bacterial endocarditis and shunt infections are also frequently associated with postinfectious GN. Moreover, the atypical postinfectious GN tends to affect mainly adults who are immunocompromised, e.g., in association with alcoholism, diabetes, and drug addiction. While spontaneous recovery within a few weeks is still the rule in children affected by the typical poststreptococcal GN, the prognosis in immunocompromised adults with postinfectious GN is significantly worse, with less than 50% in complete remission after a long follow-up.