What is the primary method for diagnosing glomerulonephritis?

The primary method for diagnosing glomerulonephritis is the determination of an antistreptolysin O (ASO) titer. This test is particularly relevant when glomerulonephritis is suspected to be secondary to a recent streptococcal infection, such as post-streptococcal glomerulonephritis. The ASO titer measures antibodies against streptolysin O, a toxin produced by Streptococcus bacteria, and elevated levels indicate a recent infection that may be associated with glomerulonephritis.

In diagnosing glomerulonephritis, a healthcare provider will typically review clinical symptoms, laboratory findings, and sometimes imaging studies. However, the ASO titer plays a crucial role in confirming the diagnosis, especially when there is a strong clinical suspicion of streptococcal involvement. Other diagnostic tests, including urinalysis and serum creatinine levels, are also essential, but the ASO titer provides specific insight into infections that could lead to glomerular injury.