Developed for the
Aerospace Medical Association
by their constituent organization
Overview: IgA nephropathy is the
most common cause of glomerulonephritis, responsible for approximately 45% of
cases. A peak incidence in the second
and third decades of life exists, but patients may present at any age. It occurs primarily in Asians and Caucasians,
rarely in blacks. IgA
nephropathy predominantly occurs in males (2:1) in North American and Western
European populations. Originally thought
to be benign, it is now known that many cases can progress to renal
failure. For the purpose of this
discussion, it is assumed the workup for hematuria and/or proteinuria has been
completed, and there is a final diagnosis of biopsy-confirmed IgA nephropathy. The
issue of biopsy may present a problem, since many nephrologists in the
Aeromedical Concerns: Flyers with IgA nephropathy may have disease ranging from totally benign to rapidly progressive renal failure. The risk of sudden incapacitation is negligible. Clinical predictors of progressive disease: 24-hour urine protein greater than 500 mg, serum creatinine 2.5 or more, and hypertension. Studies have been conducted looking for other markers of progression: the serum IgA/C3 ratio, histologic features such as crescent formation and interstitial fibrosis, and isolated microscopic hematuria, but these are recent and there’s not enough data to make them clinically useful.
Aeromedical Disposition (Military): Air Force: AFI 48-123 V3 A4.22.3 places the limit at 200 mg per 24 hours. Waivers are considered for fixed or reproducible orthostatic (postural) proteinuria, and have been granted for IgA nephropathy if the clinical predictors of disease are acceptable.
Army: Same as above.
Navy: Similar to the AF. The Navy waiver guide does not define “normal renal function.”
The urine protein/creatinine ratio (Pr/Cr) is commonly used in lieu of the 24-hour protein. However, it does have its limitations, which may be germane to aeromedical concerns. Pr/Cr accuracy relies on the assumption that daily creatinine excretion is 1000 mg (8.8 mmol)/day; it increases in muscular people, and decreases with cachetic patients. An increased creatinine excretion will underestimate proteinuria, and may be an issue in a young, muscular pilot population. Collecting this data in a younger population may yield better guidelines for its use at a later time.
Waiver Experience (Military): Waivers have been granted for IgA nephropathy if the proteinuria is below 1000 mg in 24 hours (12 of 14 cases in AIMWTS ). Review of the electronic records shows both the disqualified cases had one or more of the clinical predictors for advancing disease.
Waiver Experience (Civilian): Since there is little risk of incapacitation from IgA nephropathy itself, conditions secondary to chronic kidney failure will be important, especially blood pressure.
1. Cattran D C. Treatment and prognosis of IgA nephropathy UpToDate 2007 Retrieved September 27, 2007 from the World Wide Web: http://uptodateonline.com/online/content/topic.do?topicKey=glom_dis/10588
2. Barratt J. Causes and diagnosis of IgA nephropathy UpToDate 2007 Retrieved September 27, 2007 from the World Wide Web: http://uptodateonline.com/online/content/topic.do?topicKey=glom_dis/8139
3. Boulware L E. Screening for proteinuria in US adults. JAMA 2003: 3101-3114
4. US Air Force Instruction 48-123. Medical examinations and
5. US Army Regulation 40-501. Standards of medical fitness.
6. US Federal Aviation
Administration. Guide for Aviation Medical Examiners.
7. US Navy. Aeromedical Reference and Waiver Guide. 13 march 2007 Retrieved December 15, 2007 from the World Wide Web: http://www.nomi.med.navy.mil/NAMI/WaiverGuideTopics/index.htm
July 22, 2008