Materials and Methods
Chart Review
A retrospective review of medical records was performed for all patients who underwent orthotopic liver transplantation at Mayo Clinic in Arizona between June 6, 1999 and December 2, 2007. Patients who did not survive the surgery were excluded from the review. We recorded details of the transplantation, comorbid conditions, coccidioidal infection (if applicable) (e.g. date of infection; history of coccidioidomycosis; symptoms; extent and outcome of the infection; serologic, microbiologic, histopathologic and radiographic findings), other infections, immunosuppressive treatment, rejection of the organ and outcome of the patient. The Mayo Clinic Institutional Review Board approved our study.
Definitions
We defined the following terms for consistency throughout our study:
Confirmed coccidioidomycosis: a case in which either biopsied material showed Coccidioides spherules in direct examination or cultures of clinical specimens grew Coccidioides species.
Highly probable coccidioidomycosis: a case with positive serologic findings, symptoms typical of coccidioidomycosis and radiographic findings (such as, but not limited to, infiltrates, masses, nodules and cavities) characteristic of coccidioidal infection.
Probable coccidioidomycosis: a case with positive serologic findings and either symptoms or a radiographic finding, but not both, characteristic of coccidioidal infection.
Asymptomatic positive serology: a case with positive serologic findings but normal results on radiographic study and no identifiable illness.
Disseminated coccidioidomycosis: a case with a biopsy- or culture-proven extrapulmonary site or the presence of miliary pattern on the chest radiograph.
Coccidioidomycosis before transplantation: a case of a diagnosis of coccidioidomycosis made by a medical practitioner and supported by a description of a compatible illness that included 1 or more typical symptoms (e.g. fever, chills, sweats, respiratory symptoms, headache, rash, myalgias, arthralgias and fatigue) and typical findings on laboratory (positive results on serology, microbiology or histopathology) and radiographic (e.g. chest radiographs, computed tomographic scans) studies. This category did not include patients who did not have a formal diagnosis made by a medical professional.
Coccidioidal Serology
Patients were routinely screened with serologic testing for coccidioidomycosis, with numerous simultaneous methods at the initial evaluation, on the day of transplantation, at 3 and 12 months posttransplantation, and annually thereafter. Studies are repeated as needed to evaluate symptoms.
Multiple methods were used for identifying coccidioidal antibodies, including enzyme immunoassay (EIA) for immunoglobulin M (IgM) and immunoglobulin G (Meridian Bioscience Test Kit; Meridian Bioscience, Inc., Cincinnati, OH, USA), immunodiffusion for IgM (Meridian Bioscience Test Kit; Meridian Bioscience, Inc.) and immunoglobulin G (Gibson Laboratories Test Kit; Gibson Laboratories, Lexington, KY, USA), and complement fixation test (antigen obtained from the Coccidioidomycosis Serology Laboratory at the School of Medicine, University of California, Davis, Davis, CA, USA). When results were indeterminate, tests were repeated; if necessary, samples were sent to the Coccidioidomycosis Serology Laboratory at the School of Medicine, University of California, Davis, for further clarification.
Coccidioidomycosis Prophylaxis
The dose and duration of the coccidioidal prophylaxis after liver transplantation were based on the patient's pretransplantation history of coccidioidomycosis, the results of serologic testing, or the development of active infection posttransplantation, in accordance with previously published protocol. Patients with seronegative results who had no history of coccidioidomycosis before transplantation or who did not have coccidioidomycosis after transplantation did not receive coccidioidal prophylaxis. Patients with seronegative results who had a well-documented history of coccidioidomycosis of more than 1 year before transplantation received oral fluconazole (200 mg/day) for 6–12 months. Patients who had positive coccidioidal serologic results at transplantation or had either active infection in the 1 year before transplantation or after transplantation received lifelong prophylaxis of oral fluconazole (400 mg/day).
Noncoccidioidal, Antifungal Prophylaxis
Various (noncoccidioidal) antifungal prophylaxis regimens were used in the follow-up period, in part reflecting changes to protocol, type of transplantation procedure received, the presence or absence of biliary complications, or patient participation in studies. Nystatin was administered as part of the selective bowel decontamination study in participating patients (study period, September 1999–September 2000; n = 16). Fluconazole (200 mg/day) for 1 month was administered to patients who participated in a multicenter immunosuppression study (study period, November 2002–February 2004; n = 18) or patients who received a living donor organ in accordance with living donor protocol (June 2002–November 2007; n = 46). Patients whose transplantation course was complicated with a bile leak received fluconazole (200 or 400 mg/day), amphotericin B, liposomal amphotericin B, voriconazole or no prophylaxis, as determined on a case-by-case basis.
Pretransplantation Evaluation
All liver transplant candidates underwent a multidisciplinary evaluation that included history taking, physical examination and laboratory and radiologic testing. All candidates were carefully interviewed and examined by an infectious-disease specialist, who looked for any history or presence of infection. All identified abnormalities were further evaluated and defined. For instance, any abnormality on chest radiograph (whether active or indeterminate) was further evaluated with chest computed tomography, bronchoscopy, biopsy or other studies and treated as appropriate.
Liver Transplant Immunosuppression
Standard immunosuppression for liver transplant recipients consisted of tacrolimus with intravenous methylprednisolone, followed by oral prednisone, the dose of which was tapered and discontinued within 4 months. For patients with a serum creatinine value of 2.0 or greater, mycophenolate mofetil (MMF) (1000 mg twice daily) was added to allow lower tacrolimus levels; this dosage was reduced to 500 mg twice daily to accommodate symptomatic intolerance or cytopenia found on a complete blood cell count. Patients with primary biliary cirrhosis and autoimmune hepatitis received low-dose prednisone (5 mg/day). Patients who were not able to tolerate this type of immunosuppression received cyclosporine or sirolimus as determined on a case-by-case basis.
From November 2001 to February 2004, 19 patients participated in a multicenter immunosuppression study in which patients were randomly assigned to receive tacrolimus plus prednisone (n = 4), tacrolimus plus prednisone plus MMF (n = 6) or tacrolimus plus MMF plus daclizumab (n = 9).
Graft Rejection
Patients with biopsy-proven acute cellular rejection were treated with three doses of methylprednisolone sodium succinate (3 g total) or, occasionally, with an increase in the dose of immunosuppressive medications as decided on a case-by-case basis. To date, antilymphocyte or anti-IL-2 treatments have not been required.
Statistical Analysis
We used simple descriptive statistics for analysis of the data obtained in the study. Fisher exact test was used to assess differences among proportions of various attributes of patients who did or did not have coccidioidomycosis.