36-year-old Micronesian male presented with worsening left knee pain and swelling over the last seven days. His past medical history includes iron deficiency, chronic hepatitis B, and recently active TB. He described a throbbing pain encompassing his entire left knee. Additionally, he endorsed fatigue and night sweats without fevers, cough, or dyspnea. There is no personal or family history of immune deficiency. Seven months prior he was admitted to an outside facility due to left sided pyelonephritis and was found to have an abnormal CXR. Bronchoscopy and bronchial culture were positive for pansusceptible Mycobacterium tuberculosis. Fluid drained from his left chest wall abscess also grew Mycobacterium tuberculosis. At that time, urine acid-fast bacilli (AFB) stain was positive, and a left ureteral stent was placed for presumed TB-related pyelonephritis. However, urine Mycobacterium tuberculosis PCR was not performed. He was started on a four drug intensive phase regimen under direct supervision which he completed for two months. Currently, he takes isoniazid and rifampin for TB continuation phase along with Vitamin B6.
Physical exam revealed a warm, tender, erythematous left knee. Knee flexion was severely limited due to pain and he was unable to bear weight on his left leg. Pulmonary exam demonstrated normal lung sounds with symmetric chest rise. The remainder of the exam was unremarkable. Joint arthrocentesis produced bloody synovial fluid containing 8559 white blood cells without crystals. Subsequent cultures of this fluid yielded Cryptococcus. Magnetic resonance imaging (MRI) of his left knee, seen in Fig. 1, suggested infectious arthritis. Fungal cultures of his blood and cerebral spinal fluid were negative although serum Cryptococcal antigen was positive. During this admission, immunodeficiency work up revealed reduced levels of CD3(431 cells/mcl), CD4(269 cells/mcl), and CD8 (142 cells/mcl) T cells. HIV infection was ruled out with fourth-generation antibody/antigen combo testing at an outside hospital and at our institution. HIV 1 PCR was not requested.
Oral fluconazole was started and he underwent a left knee irrigation and drainage, synovectomy, and arthroplasty. Fig. 2 shows an intraoperative picture. A spacer was placed using amphotericin B and vancomycin cement. Intraoperative tibia samples obtained grew Cryptococcus as well.