Nocardiosis in renal transplant patients

Pulmonary Nocardiosis in Renal Transplant Recipients From Pakistan: Risk Factors, Clinical Presentation, and Mortality

OBJECTIVES

Nocardia is an opportunistic infection among renal transplant recipients with an incidence of <1% but high mortality. Data from Pakistan are scarce. Our aim was to find the risk factors, clinical and radiographic findings, antimicrobial sensitivity, and outcomes of Nocardia infection among renal transplant recipients in Pakistan.

MATERIALS AND METHODS

All adult renal transplant recipients diagnosed with nocardiosis between 2013 and 2020 were included. The cases were matched 1:2 with controls based on sex, age (±1 year), and transplant date (±1 year). Risk factors, clinical features, antibiotic sensitivities and outcomes were analyzed.

RESULTS

A total of 48 patients developed nocardiosis. Around 25% of patients presented with disseminated disease. Median time from transplant to disease development was 2.68 years. High-dose methylprednisolone and presence of cytomegalovirus infection within 90 days of disease development were independent risk factors for Nocardia infection. The mortality rate was 20%. Central nervous system disease and cytomegalovirus infection within 90 days were significantly associated with mortality. The most susceptible drugs were co-trimoxazole and linezolid. Imipenem susceptibility was only 20%.

CONCLUSIONS

High-dose methylprednisolone and cytomegalovirus infection were independent risk factors for Nocardia infection. Central nervous system disease was associated with mortality. Nocardia species were highly resistant to ceftriaxone and imipenem in our patient population.

Nocardiosis in kidney transplant recipients: A tertiary care center experience

INTRODUCTION

Kidney transplant recipients are at increased risk of opportunistic infections, including Nocardia. The incidence of nocardiosis in kidney transplant recipients is 0.4-1.3%. The data regarding its epidemiology and outcomes is limited.

METHODS

This was a 10-year retrospective observational study from January 2012 to December 2021 at a tertiary care center in northern India, in which all kidney transplant recipients with Nocardia infection were included and followed.

RESULTS

12 (1.1%) patients had a Nocardia infection among the 1108 kidney transplant recipients. All were living donor kidney transplant recipients, and the mean age at diagnosis was 48.67 ± 12.60 years. Nocardia infection occurred at a median of 26 months (range 4-235) post-transplantation, with 4 (33.1%) of the cases occurring within a year of transplant. Breakthrough infection occurred in 7 (58.3%) patients on cotrimoxazole prophylaxis. 41.7% (n = 5) cases had an episode of rejection in the preceding year of Nocardia diagnosis. Concurrent cytomegalovirus (CMV) infection was present in one (8.3%) case. The lung was the most frequently involved organ. Microscopy was positive in all the cases; while culture was positive in 10 cases, and antimicrobial susceptibility testing (AST) were performed for these isolates. The majority (60%) of isolates were resistant to cotrimoxazole. All tested isolates remained susceptible to Amikacin, Imipenem, and Linezolid. No patients experienced Nocardia recurrence after completion of antibiotic therapy. The mortality at 12 months was 66.7% (n = 4), and only one death was Nocardia-related.

CONCLUSION

Nocardia may cause a late-manifesting infection beyond the traditional window. The cotrimoxazole prophylaxis may not be sufficient for Nocardia prevention.

Cutaneous squamous cell carcinoma and mortality in end-stage renal disease

BACKGROUND

In the general population, cutaneous squamous cell carcinoma (cSCC) is associated with increased all-cause mortality. Transplant patients have been shown to have an increased risk of developing cSCC, and their cSCC is associated with an increased risk for mortality. In end-stage renal disease (ESRD) patients, there is extensive mortality and immune dysfunction. Because of this immune system dysfunction, we examined whether cSCC is associated with increased risk of all-cause mortality among ESRD patients, as well as the risk factors for cSCC.

METHODS

We analyzed ESRD patients in the United States Renal Data System from 2004-2014, excluding organ transplant recipients. We assessed mortality using a Cox Proportional Hazards (CPH) model to control for various demographic and clinical parameters, identified using international classification of diseases (ICD)-9 codes.

RESULTS

Of the 1,035,193 patients included, 624 (0.1%) were diagnosed with cSCC. The median survival time for those with cSCC was 3.91 years [95% confidence interval (CI) = 3.67-4.15], versus 2.92 years [95%CI = 2.92-2.93] for patients without cSCC. ESRD patients with cSCC were at lower risk of death [adjusted hazard ratio = 0.75; 95%CI = 0.69-0.82] compared to those without. Decreased risk of death was also associated with parameters such as black race, Hispanic ethnicity, tobacco dependence and actinic keratosis. Increased mortality risk was associated with increasing age, male sex, hemodialysis (versus peritoneal dialysis) and alcohol dependence.

CONCLUSIONS

Contrary to expectations, ESRD patients with a cSCC diagnosis showed reduced all-cause mortality risk relative to those without. The reason for this discrepancy remains unclear, suggesting the need for further study.

Successful Management of Combined BK Nephropathy and Nocardiosis in a Renal Transplant Recipient: Case Report

Nocardiosis is a life-threatening infection in immunocompromised patients. The prevalence of the disease ranges from 2.3% to 5% in renal allograft recipients. Here, we describe a case of BK nephropathy associating with nocardiosis with successful recovery. The 54-year-old male patient had end-stage kidney disease due to diabetic nephropathy associated with diabetic retinopathy, hypertension, and dyslipidemia. He started hemodialysis in October 2017; 2 years later, he underwent a deceased donor kidney transplant with 2 HLA mismatches and high panel reactive antibodies. He received desensitization with intravenous immunoglobulin and rituximab, received thymoglobulin as induction, and was maintained on prednisolone, mycophenolate mofetil, and tacrolimus. His serum creatinine decreased to a nadir of 90 μmol/L. He developed graft dysfunction, which was proven to be due to BK nephropathy. Therefore, mycophenolate mofetil was replaced with leflunomide in addition to intravenous immunoglobulin therapy. Ten months later, he had an accidental fall and sought an orthopedic evaluation. Magnetic resonance imaging of the lumbar spine and pelvis revealed lumbar spondylosis, avascular necrosis of the femoral head, and obturator muscle abscess. He was explored surgically, but the surgeon found no abscess or avascular hip necrosis. The patient's blood grew Nocardia, and he was readmitted and started imipenem and linezolid empirically. Brain and chest computed tomography scans ruled out any central nervous system or pulmonary involvement, but a bone scan revealed osteomyelitis of the right superior pubic ramus and prepubic swelling, which was confirmed by computed tomography to be an abscess in both obturator externus and internus. He continued the same antibiotics for 6 months based on culture and sensitivity. At follow-up, the patient has shown stable graft function (creatinine 155 μmol/L) with improved BK viremia with immunosuppression minimization. In renal transplant recipients, successful management of combined BK nephropathy and nocardiosis was feasible with minimization of immunosuppression and proper antimicrobial therapy.