According to a recent journal, a case study found that the development of anti-glomerular basement membrane disease (anti-GBM) may be triggered by COVID-19.
Anti-glomerular basement membrane disease (anti-GBM disease) is a disease that occurs as a result of injury to small blood vessels (capillaries) in the kidneys and/or lungs. Autoantibodies are antibodies directed toward the body itself (rather than towards something foreign such as bacteria or viruses). In anti-GBM disease, these autoantibodies are targeted to the basement membrane, which is part of the wall of these capillary blood vessels in the kidneys and lungs. The name anti-GBM disease reflects the fact that this disease is caused by autoantibodies targeting and causing damage to (anti-) the glomerular basement membrane (GBM).
Anti-GBM disease can affect just the kidneys or both the lungs and kidneys (it is uncommon for only the lungs to be affected). The reason these organs are affected is because the basement membrane is targeted in this disease and is only accessible to antibodies in the kidneys and lungs. About half of people with anti-GBM disease have lung involvement. Anti-GBM disease that only affects the kidneys is called anti-GBM glomerulonephritis. This is because there is inflammation (-itis), occurring in the glomeruli (filters) of the kidney. Anti-GBM disease affecting both the kidneys and lungs is often called Goodpasture’s syndrome or Goodpasture’s disease (though anti-GBM disease is the preferred term now).
When there is lung involvement, symptoms can include:
- Coughing up blood
- Cough (without blood)
- Shortness of breath/difficulty breathing (and even respiratory failure)
- Chest pain
When the kidneys are affected, this can cause:
- Low kidney function (kidney injury) or kidney failure, which can cause symptoms including fatigue, nausea/vomiting, poor appetite or weight loss, metallic taste in the mouth, and confusion or decreased alertness. However, most people with kidney injury or damage do not have a lot of symptoms until they are in kidney failure.
- Blood in the urine – this may or may not be visible
- Foamy urine (from protein in the urine)
The study, which was done in Madurai Medical College, took place from September 2020 to March 2021. Researchers looked at four cases of patients who contracted COVID-19 and later went on to present with anti-GBM disease. The patients studied had new-onset rapidly progressive glomerulonephritis and biopsy-proven anti-GBM disease with a COVID antibody present. They looked at the clinical features, anti-GBM titer, renal parameters, kidney biopsy pattern, progression to end-stage kidney disease, and responses to treatment.
Researchers wanted to examine this connection because a COVID-19 infection can lead to severe endothelial injury and disturbed endothelial cell membranes. This, therefore, may be an initiating event for exposing the cryptic basement membrane antigen
The case series showed that there was possibly a pathogenic association between COVID-19 and anti-GBM disease. This association causes a rapidly progressive form of crescentic glomerulonephritis. While the relationship is still speculated, there has been an increased number of new anti-GBM disease diagnoses after a COVID-19 infection.