Clinical validation of immunoglobulin A nephropathy diagnosis in Swedish biopsy registers

• Aims: The aims of this study were to validate the diagnosis of IgA nephropathy (IgAN) in Swedish biopsy registers against patient charts and to describe the clinical characteristics of patients with a biopsy indicating IgAN.Methods: This is a population-based cohort study. Out of 4,069 individuals with a renal biopsy consistent with IgAN (biopsies performed in 1974-2011), this study reviewed patient charts of a random subset of 127 individuals. Clinical and biopsy characteristics at the time of biopsy were evaluated, and positive predictive values (PPV) were calculated with 95% confidence intervals (CI).Results: Out of 127 individuals with a renal biopsy consistent with IgAN, 121 had a likely or confirmed clinical diagnosis of IgAN, primary or secondary to Henoch-Schonlein purpura, yielding a PPV of 95% (95% CI =92%-99%). The median age at biopsy was 39 years (range: 4-79 years); seven patients (6%) were <16 years. The male to female ratio was 2.8:1. The most common causes for consultation were macroscopic hematuria (n=37; 29%), screening (n=33; 26%), and purpura (n=14, 11%). In patients with available data, the median creatinine level was 104 mu mol/L (range 26-986 mu mol/L, n=110) and glomerular filtration rate 75 mL/min/1.73m(2) (range 5-173 mL/min/1.73m(2), n=114). Hypertension was noted in 59 (46%) individuals. IgA deposits were reported in 97% of the biopsy records (n= 123), mesangial hypercellularity in 76% (n= 96), C3 deposits in 89% (n=113), and C1q deposits in 12% (n=15). Conclusion: A histologic diagnosis of IgAN has a high PPV for a diagnosis of IgAN confirmed by review of patient charts.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap -- Arbetsmedicin och miljömedicin (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Occupational Health and Environmental Health (hsv//eng)

Nyckelord

general population-based

histopathology

IgA nephropathy

kidney

renal disease

validation studies

Publikations- och innehållstyp

ref (ämneskategori)

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