The incidence of primary glomerulonephritis worldwide: a systematic review of the literature

Background: This systematic literature review of the epidemiology of Guillain-Barré syndrome (GBS) identifies trends in incidence rates by age, study method and cause of disease. It is important to have a reliable estimate of incidence to determine and investigate any changes: no previous systematic reviews of GBS have been found. Methods: After critical assessment of the reliability of the reported data, incidence rates were extracted from all relevant papers published between 1980 and 2008, identified through searches of Medline, Embase and Science Direct. Results: Sixty-three papers were included in this review; these studies were prospective, retrospective reviews of medical records or retrospective database studies. Ten studies reported on the incidence in children (0–15 years old), and found the annual incidence to be between 0.34 and 1.34/100,000. Most studies investigated populations in Europe and North America and reported similar annual incidence rates, i.e. between 0.84 and 1.91/100,000. A decrease in incidence over the time between the 1980s and 1990s was found. Up to 70% of cases of GBS were caused by antecedent infections. Conclusions: Our best estimate of the overall incidence of GBS was between 1.1/100,000/year and 1.8/100,000/year. The incidence of GBS increased with age after 50 years from 1.7/100,000/year to 3.3/100,000/year.

Against the background of the increasing incidence of many immune mediated childhood conditions, this study aimed to identify recent time trends and ethnic patterns of childhood nephrotic syndrome. A population-based cohort of children (0-15 years) diagnosed according to strict criteria with nephrotic syndrome (NS) was ascertained within the northern UK region of Yorkshire between 1987 and 1998. South Asian ethnicity was assigned based on the child's full name using a dedicated computer algorithm and expert individual checks. NS was diagnosed in 194 children, 170 (88%) of whom were steroid sensitive. The incidence of steroid sensitive NS was 2.0/100,000 pyrs (95% CI 1.7-2.3), peaking in 1-4 year olds (4.1/100,000 pyrs). Over the 12-year study period incidence rates of steroid sensitive NS were fairly stable although south Asian children displayed significantly higher rates than non-south Asians (P<0.01). The size of our population-based series reflects the relative rarity of paediatric nephrotic syndrome but is nonetheless recent and includes larger numbers than previous reports. The absence of any increase in incidence over the last decade contrasts with other paediatric immune mediated conditions such as asthma and diabetes.