Silent Perforated Diverticulitis in a Kidney Transplant Patient With Autosomal Dominant Form of Polycystic Kidney Disease

Introduction: Large bowel and colonic diverticulosis are among the common extrarenal manifestations of the autosomal dominant form of polycystic kidney disease (ADPKD), notably, with a prevalence of 4.1% for diverticulosis and 1.2% for diverticulitis. Additionally, those patients with kidney transplant and on immunosuppressive therapy are at an increased risk of bowel perforation. Case Description/Methods: Our patient is a 64-year-old man with a past medical history of ADPKD treated with nephrectomy and kidney transplant on tacrolimus, mycophenolate mofetil, and prednisone. He presented to our hospital for total knee arthroplasty. The procedure was performed successfully with no complications and with minimal blood loss. On day two, he complained of mild lower abdominal pain after a bowel movement. Physical exam showed stable vital signs and mild lower abdominal tenderness with negative peritoneal signs. Moreover, laboratory work was unremarkable. The patient was placed on nothing by mouth, and conservative measures were initiated. An urgent computerized tomography (CT) scan of the abdomen and pelvic with oral contrast revealed perforated sigmoid and diverticulitis with moderate pneumoperitoneum (Figure 1). Intravenous antibiotics were started. Furthermore, laparotomy, sigmoidectomy, and colostomy were urgently performed. He had a complete recovery and was discharged home. Discussion: The ADPKD is the most common life-threatening monogenic disease, affecting 12 million people worldwide. ADPKD is commonly associated with colonic diverticulosis, most commonly in the sigmoid. Interestingly, colonic perforation is facilitated by immunotherapy's suppressive influence on collagen formation. Also, it suppresses inflammatory cells and pain-inducing prostaglandins, thereby concealing the natural inflammatory response. Adults with perforated sigmoid treated with primary resection have a high mortality rate, occurring in up to 45% of patients. This case demonstrates that a high index of suspicion is required in this population of patients as typical symptoms may not appear in immunocompromised individuals. Nevertheless, early detection and treatment can prevent life-threatening outcomes.Figure 1.: CT scan of the abdomen and pelvis with oral contrast.