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?

Lab Diagnosis of PSGN: Antistreptolysin O (ASO) titer is commonly elevated after a pharyngeal infection but rarely increases after streptococcal skin infections.(as in this case) Best single antibody to document cutaneous streptococcal infection is anti deoxyribonuclease (DNase) B level. Other Lab tests of PSGN: The serum C3 level is significantly reduced in >90% of patients, and returns to normal 6-8 wk after onset. C4 is most often normal. Serum CH50 is commonly depressed A biopsy is rarely indicated when: renal function is severely impaired beyond 7-10 days serum C3 remains depressed beyond 12 weeks Patient with features of a systemic illness