What is the likely diagnosis in a patient who has low back ache, L3 tenderness, and the following data: total proteins 8.9 g/dL, albumin:globulin ratio 2.9/5.9 (reversed), serum creatinine 5.5 mg/dL, TLC 4500/mm3, DLC neutrophils 55%, lymphocytes 40%, eosinophils 2%; blood urea was 93 mg/dL and serum creatinine was 1.2 mg/dL; ESR was 90 mm in the first hour?