A 61-year-old woman with a kidney-pancreas transplant in 2004 followed by a second kidney transplant in 2017 presented to the emergency department with recurrent falls in the setting of several weeks of diarrhea with generalized weakness and progressive bilateral lower extremity swelling. Prior to admission, the patient was having 6 to 7 loose bowel movements per day for 2 weeks. The number of episodes and volume were not affected by food intake. The large-volume, high-frequency diarrhea was debilitating and subsequently led to decreased oral intake and a decline in her overall nutritional status. Additional medical history was pertinent for type 2 diabetes. For her transplantation, she had been induced with anti-thymocyte globulin, and maintenance immunosuppression at the time of admission consisted of tacrolimus, mycophenolate mofetil, and prednisone. Social history was unremarkable. She lived alone, denied sick contacts, did not smoke or drink, and had not traveled in or outside the country.
On admission to our institution, vital signs demonstrated a temperature of 36.4 C, blood pressure of 131/68 mm Hg, heart rate of 64 beats per minute, respiratory rate of 16 breaths per minute, and oxygen saturation of 97% on room air. Her weight was 47.2 kg and body mass index was 17.32 kg/m2. Physical examination revealed a pale, frail, ill-appearing lady with generalized muscle wasting in her extremities, bilateral temporal wasting, and loss of her buccal pad of fat. She had 2 plus pitting lower extremity edema up to the hips. There was no fluid wave on abdominal examination.
Renal function tests demonstrated a creatinine of 4.5 mg/dL (increased from baseline 3.5 mg/dL), blood urea nitrogen of 65 mg/dL, and bicarbonate of 16 mmol/L. Serum albumin was 1.7 g/dL. Complete blood count demonstrated hemoglobin of 6.8 g/dL (baseline, 7.5-9 g/dL), mean corpuscular volume of 91.5 fL, and white blood cell count of 6.37K/cumm. Gastrointestinal (GI) polymerase chain reaction was tested and was negative on 2 occasions. Fecal calprotectin and fecal leucocytes were also negative. The stool was negative for cyclospora.
Due to her severe diarrhea and cytomegalovirus (CMV) plasma viral load of 1823 IU/mL, intravenous ganciclovir was started for a presumed diagnosis of CMV colitis. Colonoscopy showed a few sessile polyps with a few diverticula but was overall unremarkable. Colonic biopsies were negative for CMV on histopathological examination. Given her persistent symptoms despite ganciclovir therapy, an upper endoscopy was performed, which demonstrated erosive gastropathy and mucosal changes with nodularity in the first and second parts of the duodenum.(Figure 1A, B)
On hospital day 7, ova and parasite stool study returned 3+ positive for acid fast bacteria (AFB). Around the same time, blood cultures also turned AFB-positive. Histopathologic results from the duodenal biopsy demonstrated abundant AFB organisms present within lamina propria macrophages and acid fast organisms consistent with mycobacteria seen on Kinyoun stain (auramine-rhodamine-positive, periodic acid-Schiff with diastase-positive) (Figure 1C and D).
Transplant infectious disease team was consulted and she was started on a multidrug regimen to cover both NTM and mycobacterium tuberculosis, adjusting for renal function, with ethambutol, azithromycin, rifabutin, amikacin, isoniazid, and moxifloxacin.
Unfortunately, despite appropriate treatment and supportive measures, our patient continued to deteriorate. She developed respiratory distress and acute hypoxic respiratory failure requiring transfer to the intensive care where she was intubated. Chest imaging demonstrated bilateral multifocal pneumonia with bilateral pleural effusions. Bronchoalveolar lavage and pleural fluid analysis returned AFB-positive, confirming a diagnosis of disseminated NTM. The organism was later identified as Mycobacterium avium complex (MAC).
Over the next few days, her kidney function continued to deteriorate and she ultimately lost renal graft function all together. Her tenuous hemodynamics did not permit intermittent hemodialysis and she needed to be on continuous renal replacement therapy. After spending 2 months in the hospital with repeated trips to intensive care, she succumbed to the disseminated infection.