Question: The patient was diagnosed with Crohn's disease of the colon at the age of 39 years and had a chronic active disease course with rapid response to infliximab. Biopsies from the colon showed extensive inflammation with granulomas. The patient had secondary loss of response to infliximab due to formation of antidrug antibodies (ADA). She did not tolerate azathioprine or 6-mercaptopurine owing to pancreatitis and had severe hair loss when treated with methotrexate. Owing to previous good response to anti-TNF treatment, the patient was given adalimumab and subsequently certolizumab pegol, both with good initial responses, but unfortunately with subsequent loss of response caused by ADA formation. The patient also had significant extraintestinal manifestations (iridocyclitis, sacroiliitis, and peripheral arthropathies) that tended to respond to biologics. At the age of 45, the patient was switched to golimumab with good symptomatic control of the disease and extraintestinal manifestations, but fluctuating Creactive protein levels between 0.5 and 2.5 mg/dL. At the age of 48, her estimated glomerular filtration rate decreased to <60 mL/min with more rapid decreases in periods with elevated inflammatory markers (Figure A). Urinalysis revealed proteinuria and no occult blood. Urinary excretion of protein was between 0.2 and 0.6 g/d. An initial ultrasound examination of the kidneys and urinary tracts was normal and a Tc-99-MAG3 renography showed bilateral decreased kidney function. A kidney biopsy was performed (Figure B). What is the diagnosis and treatment? Look on page 59 for the answer and see the Gastroenterology website (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and images in GI.