A 9-year-old boy is brought with history of decreased urine output, cola colored urine and swelling of the face and hands, of 2 days duration. He is hypeensive, has a puffy face and pitting edema of the lower limbs. He has history of skin lesions 4 weeks earlier. A diagnosis of post streptococcal glomerulonephritis is made. ASO titers are likely to be?

**Core Concept**
The underlying principle being tested is the relationship between post-streptococcal glomerulonephritis (PSGN) and Anti-Streptolysin O (ASO) titers. PSGN is a complication of streptococcal infection, typically occurring after a latency period.

**Why the Correct Answer is Right**
PSGN usually occurs 1-3 weeks after a streptococcal infection, and ASO titers are often low or negative by the time the renal symptoms appear. This is because ASO titers typically peak 2-3 weeks after the infection and then decline.

**Why Each Wrong Option is Incorrect**
**Option A:** This option would be incorrect because high ASO titers are usually seen during the acute phase of the infection, not during the onset of PSGN.
**Option B:** This option is also incorrect as very high ASO titers are not expected during the onset of PSGN.
**Option D:** This option is incorrect because very low ASO titers may be seen, but the most accurate answer choice should reflect the expected timing of ASO titer levels in relation to PSGN onset.

**Clinical Pearl / High-Yield Fact**
It's crucial to remember that ASO titers are often negative in PSGN due to the timing of the infection and the immune response.

**Correct Answer:** D. Low or negative

✓ Correct Answer: B. Not elevated