Febrile renal transplant recipient with discordant findings of 99mTc-Leukoscan (Sulesomab) and 67Ga-citrate scan in pyelonephritis
Single 19-year-old male, a renal transplant recipient presented with history of fever with gradual rise in the white blood counts (WBC) and serum creatinine over 2 months. The patient underwent pre-emptive renal transplant a year ago as he was diagnosed to have chronic kidney disease with bilateral reflux nephropathy. Post-renal transplant the patient was on regular immunosuppressant therapy with steroids for 10 months, he started having episodes of febrile illness since 2 months. Patient developed complications of miliary tuberculosis with recurrent secondary evidence of pseudomonal urinary tract infection for which apart from steroids, immunosuppressants, he was started on AKT (Anti-tubercular medication containing ethambutol 500mg, isoniazid 300mg, pyrazinamide 750mg and rifampicin 450mg), antibiotics and antihypertensives. On examination there was tenderness in right loin. The ultrasound revealed unremarkable both native kidneys and normal sized transplant kidney with prominent cortices. Blood investigations revealed raised WBC, normal biochemistry tests, marginally raised cyclosporine levels, Cytomegalo Virus (CMV) was negative. Urine routine examinations revealed 15-20 pus cells and urine culture showed rich growth of pseudomonas aeruginosa.\nA dose of 740 MBq (20 mCi) of 99mTc-Sulesomab (99mTc-Leukoscan) was injected intravenously and planar early as well as delayed whole body images were acquired in anterior and posterior projections at 2 h and 24 h respectively. Following this a dose of 148 MBq (4mCi) of 67Ga-Citrate was injected intravenously and planar whole body anterior and posterior images were acquired at 48 h.\n99mTc-Leukoscan [] revealed the transplant renal graft located in the right iliac fossa, appears normal in size and reveals inhomogeneous radiotracer uptake. It revealed relatively reduced radiotracer uptake in the upper pole (two areas) and in the lower pole (single area) with normal physiological uptake in the midpole region (functioning renal parenchyma revealing normal excretory phase). There is a faint visualization of the native right kidney in the 2 h and 24 h images. The native left kidney is not visualized throughout the study. Normal biodistribution of 99mTc-Sulesomab is seen in salivary glands, liver, spleen, blood pool, bone marrow, bladder and gut.\n67Ga-Citrate scintigraphy [] acquired at 48 h revealed abnormal diffuse accumulation of tracer in the native right kidney and two focal areas of increased tracer uptake involving the upper pole and a focal area of tracer uptake in the lower pole of the transplanted kidney (corresponding to the relatively reduced radiotracer uptake areas seen on 99mTc-Leukoscan).\nThis report shows diffuse pyelonephritic involvement of the native right kidney, the upper and lower poles of transplant kidney revealing discordance in uptake in 99mTc-leukoscan and 67Ga-Citrate scan in the transplant kidney.