Invasive Aspergillosis after Renal Transplantation

Abstract

Over 95,000 renal transplantation procedures were completed in 2021. Invasive aspergillosis (IA) affects about 1 in 250 to 1 in 43 renal transplant recipients. About 50% of cases occur in the first 6 months after transplantation; the median time of onset is nearly 3 years. Major risk factors for IA include old age, diabetes mellitus (especially if prior diabetic nephropathy), delayed graft function, acute graft rejection, chronic obstructive pulmonary disease, cytomegalovirus disease, and neutropenia. Hospital construction, demolition activities, and residential refurbishments also increase the risk. Parenchymal pulmonary infection is the most common (~75%), and bronchial, sinus, cerebral, and disseminated disease are less common. Typical pulmonary features of fever, dyspnea, cough, and hemoptysis are seen in most patients, but 20% have non-specific general features of illness. Non-specific infiltrates and pulmonary nodules are the commonest radiological features, with bilateral disease carrying a worse prognosis. Bronchoscopy for direct microscopy, fungal culture, and Aspergillus antigen are the fastest means of establishing the diagnosis; a positive serum Aspergillus antigen presages a worse outcome. Standard therapy includes voriconazole, isavuconazole, or posaconazole, with great attention necessary to assess likely drug-drug interactions. Liposomal amphotericin B and echinocandins are less effective. A reduction in or stopping immunosuppression needs careful consideration, given the overall mortality of IA in renal-transplanted patients; continuing corticosteroid after the diagnosis of IA increases mortality by 2.5 times. Surgical resection or the addition of a gamma interferon should also be considered.

Keywords: antifungals; immunosuppression; invasive aspergillosis; renal transplantation.

Figure 1

Chest X-ray of invasive aspergillosis in 58-year-old renal transplant recipient shows bilateral infiltrates.

Figure 2

HRCT images of invasive aspergillosis in 58-year-old renal transplant recipient show (a) right-sided wedge-shaped consolidation with ground glass changes in the right lower lobe, (b) left upper lobe patchy consolidation with ground glass changes laterally, (c) thin-walled cavitation with fluid level and material in the cavity in the right lower lobe after 6 weeks of voriconazole, and (d) residual findings of the right lower lobe after 2 years of initial presentation and voriconazole treatment showing thin-walled cavity medially, an aspergilloma, and pleural thickening.