Proteinurea In A Ten Month Old With Fever

A 10 months old weight 3.4 kg Hb 2 gm % TLC, DLC ,Platelet WNL, urine--protein --(4+), RBC--0-1, WBC-3-4, GRANULAR CAST 1-2, SP GR--1.020. He is having high grade fever non responding to ceftriaxone, inj piperacilin, inj amikacin, typhidot, scrub, malaria negative, cxr pa nad, montoux negative, USG KUB NAD.

What to do now?