Invasive bacillary angiomatosis in a kidney transplant recipient: A challenging case on belatacept immunosuppression.

Bacillary angiomatosis is a disseminated vascular proliferative disease caused by aerobic gram-negative bacilli Bartonella henselae or Bartonella quintana. Bacillary angiomatosis is mostly described in immunosuppressed patients with HIV infection and organ transplant recipients. We describe the case of a female aged 75 years who is a kidney transplant recipient who was admitted for a 3-month history of intermittent fever, chills, vomiting, and a 12-kg weight loss. The maintenance immunosuppression was based on prednisone, mycophenolate, and monthly infusions of belatacept. Physical examination was unremarkable. Laboratory investigations revealed elevated blood acute phase proteins but all blood cultures were negative. Serological tests for Bartonella were negative. Thoracoabdominal computed tomography scan and transesophageal echocardiography were normal. A Positron Emission Tomography scan showed a hypermetabolic mass in the duodenopancreatic region, with multiple hepatic and splenic lesions. Histological findings of spleen and pancreatic biopsies were not conclusive. The histopathological examination of a celiac lymph node biopsy finally demonstrated bacillary angiomatosis. The diagnosis of bacillary angiomatosis in immunocompromised patients is most often delayed in the absence of skin involvement. A high index of clinical suspicion is needed when interpreting negative results.