Immunosuppression reduction in liver and kidney transplant recipients with suspected bacterial infection: A multinational survey

Severe pneumonia caused by Nocardia otitidiscaviarum in a patient with bronchiectasis and IgA nephropathy: a case report

Background

Nocardia species are rare opportunistic pathogens in the clinic, with strong invasiveness and dissemination, that can cause serious pulmonary infection, especially in immunocompromised patients, chronic lung diseases and hormone use, and is easy to be missed and misdiagnosed, preventing patients from obtaining timely and effective treatment, resulting in a high mortality rate.

Case presentation

Here, we present a rare case of a patient with chronic bronchiectasis and IgA nephropathy who developed Nocardia otitidiscaviarum pneumonia shortly after hormone therapy. The patient presented with tongue and lip ulcers, chest distress, cough, expectoration, and fever as the initial symptoms, which were extremely similar to common bacterial pulmonary infections. The laboratory examination and pulmonary computer tomography results indicated pulmonary infection, but the blood and multiple sputum cultures failed to identify the pathogen. Empirical treatment with piperacillin/tazobactam sodium and ceftriaxone was ineffective, and the patient's condition worsened and progressed to respiratory failure. Subsequently, a bronchoscopy examination was performed, and the bronchoalveolar lavage fluid was collected for bacterial culture, which indicated Nocardia infection, however the treatment used of trimethoprim-sulfamethoxazole combined with imipenem was not effective. Finally, the patient was confirmed to have Nocardia otitidiscaviarum infection by mass spectrometry. According to the antibiotic sensitivity test and minimum inhibitory concentration (MIC) value results, Nocardia otitidiscaviarum was resistant to imipenem, so the treatment was changed to trimethoprim-sulfamethoxazole combined with linzolid. The patient's condition improved rapidly and he was discharged after his condition was stable.

Conclusion

This case reminded us that for patients with a history of chronic lung disease, when pulmonary infection occurs during hormone or immunosuppressive therapy for kidney disease, the possibility of Nocardia infection should be fully considered, and high-quality specimens should be collected as early as possible. Appropriate bacterial culture methods and efficient identification techniques should be adopted to promptly identify pathogens, and personalized treatment plans should be developed based on antibiotic sensitivity tests to save patients' lives.

Cardoso F, P. Marques H. Carbapenem-Resistant Enterobacteriaceae Colonization or Infection Was Not Associated with Post-Liver Transplant Graft Failure: An Observational Cohort Study

Introduction

Carbapenem-resistant Enterobacteriaceae (CRE) epidemiology among liver transplant (LT) recipients is variable. We studied the impact of CRE colonization and infection on LT recipients' outcomes.

Methods

This observational cohort study included consecutive adult LT recipients between January 2019 and December 2020 at Curry Cabral Hospital, Lisbon, Portugal. Primary exposures were CRE colonization (rectal swabs under a screening program) and infection within 1 year of index LT. Primary endpoint was graft failure within 1 year of the index LT.

Results

Among 209 patients, the median (interquartile range [IQR]) age was 57 (47-64) years and 155 (74.2%) were male. CRE colonization was identified in 28 (13.4%) patients during the first year posttransplant (median [IQR] number of rectal swabs per patient of 4 [2-7]). CRE resistance genes identified were OXA48 in 8 (3.6%) patients, KPC in 19 (67.9%) patients, and VIM in 1 (3.6%) patient. Any bacterial/fungal and CRE infections were diagnosed in 88 (42.1%) and 6 (2.9%) patients, respectively, during the first year posttransplant. After adjusting for confounders, neither CRE colonization (aOR [95% CI] = 1.83 [0.71-4.70]; p = 0.21) nor infection (aOR [95% CI] = 1.35 [0.17-11.06]; p = 0.78) was associated with graft failure within 1 year of index LT.

Discussion/Conclusion

Under a screening program, CRE colonization and infection prevalence was low and neither was associated with graft failure.

Basics and Art of Immunosuppression in Liver Transplantation

Liver transplantation is one of the most challenging areas in the medical field. Despite that, it has already been established as a standard treatment option, especially in decompensated cirrhosis and selected cases of hepatocellular carcinoma and acute liver failure. Complications due to graft rejection, including mortality and morbidity, have greatly improved over time due to better immunosuppressive agents and management protocols. Currently, immunosuppression in liver transplant patients makes use of the best possible combinations of effective agents to achieve optimal immunosuppression for long-term graft survival. Induction agents are no longer used routinely, and the aim is to provide minimal immunosuppression in the maintenance phase. Currently available immunosuppressive agents are mainly classified as biological and pharmacological agents. Though the protocols may vary among the centers and over time, the basics of effective use usually remain similar. Most protocols use the combination of multiple agents with different mechanisms of action to reduce the dose and minimize the side effects. Along with the improvement in operative and perioperative techniques, this art of immunosuppression has contributed to the recent progress made in the outcomes of liver transplants. In this review, we will discuss the various types of immunosuppressive agents currently in use, the different protocols of immunosuppression used, and the art of optimal use for achieving maximum immunosuppression without increasing toxicity. We will also discuss the practical aspects of various immunosuppression regimens, including drug monitoring, and briefly discuss the concepts of immunosuppression minimization and withdrawal.

A, Sivaprasadan S, S. S. Immunosuppression in Liver Transplant Recipients in the Setting of Sepsis

Management of immunosuppression (IS) in liver transplant recipients in the setting of sepsis is an open stage for debate. The age-long practice of reduction or complete cessation of IS during sepsis has been followed by most centres across the world, although, their exact strategies are highly heterogeneous. On the other hand, the emergence of striking new evidence suggesting that there is, in fact, decreased mortality with the continuation of IS in sepsis, has raised doubts about our previously conceived intuitive notion that IS portends increased risk in sepsis. The theory postulated is that IS agents, perhaps reverse the state of dysregulated immune response in sepsis to that of an iatrogenically modulated immune response, thus dimming the inflammatory cascade and preventing its deleterious effects. Of note, none of these studies reported exaggerated rejection-related complications. These contrasting outlooks have made it rather onerous to formulate an evidence-based recommendation for liver transplant recipients afflicted with sepsis. Inclusion of transplanted patients in randomised controlled trials of sepsis-related interventions seems to be the need of the hour.

Recent advancements and perspective of ciprofloxacin-based antimicrobial polymers

In recent years, microbial pathogens, which are major sources of infections, have become a widespread concern across the world. The number of deaths caused by infectious diseases is continually rising, according to World Health Organization records. Antimicrobial resistance, particularly resistance to several drugs, is steadily growing in percentages of organisms. Ciprofloxacin is a second-generation fluoroquinolone with significant antimicrobial activity and pharmacokinetic characteristics. According to studies, many bacteria are resistant to the antibiotic ciprofloxacin. In this article, we look into polymers as ciprofloxacin macromolecular carriers with a wide range of antibacterial activity. We also discuss the latter form of coupling, in which ciprofloxacin and polymers are covalently bonded. This article also discusses the use of antimicrobial polymers in combination with ciprofloxacin in a various sectors. The current review article provides an overview of publications in the last five years on polymer loaded or modified with ciprofloxacin having applications in numerous sectors.

Isavuconazole and Liposomal Amphotericin B as Successful Combination Therapy of Refractory Invasive Candidiasis in a Liver Transplant Recipient: A Case Report and Literature Review

Invasive fungal infections in liver transplant recipients are associated with elevated morbidity and mortality and pose a challenge to the treating physicians. Despite of lacking clinical data, the use of antifungal combination therapy is often considered to improve response rates in an immunocompromised patient population. We herein report a case of refractory invasive candidiasis in a liver transplant recipient treated successfully with a combination of isavuconazole und high-dose liposomal amphotericin B. The antimycotic combination treatment was able to clear a bloodstream infection with C. glabrata and led to regression of bilomas among tolerable side effects. The use of the above-mentioned antifungal combination therapy in a liver transplant recipient has not been reported previously. This case highlights the efficacy and safety of antifungal combination therapy in immunocompromised patients with refractory invasive candidiasis.

Nanogels: A novel approach in antimicrobial delivery systems and antimicrobial coatings

The implementation of nanotechnology to develop efficient antimicrobial systems has a significant impact on the prospects of the biomedical field. Nanogels are soft polymeric particles with an internally cross-linked structure, which behave as hydrogels and can be reversibly hydrated/dehydrated (swollen/shrunken) by the dispersing solvent and external stimuli. Their excellent properties, such as biocompatibility, colloidal stability, high water content, desirable mechanical properties, tunable chemical functionalities, and interior gel-like network for the incorporation of biomolecules, make them fascinating in the field of biological/biomedical applications. In this review, various approaches will be discussed and compared to the newly developed nanogel technology in terms of efficiency and applicability for determining their potential role in combating infections in the biomedical area including implant-associated infections.

How do I manage nocardiosis?

BACKGROUND

Nocardiosis is a rare infection that is often difficult to treat and may be life-threatening. There is no consensus on its management.

OBJECTIVES

Our aim was to provide the current evidence for the diagnosis and management of individuals with nocardiosis, and to propose a management approach for this uncommon infection.

SOURCES

We systematically searched the medical literature on nocardiosis for studies published between 2010 and 2020 and describing ten or more individuals.

CONTENT

Nocardiosis, a primarily opportunistic infection which may occur in immunocompetent persons, most commonly involves the lungs and frequently disseminates to other sites including the central nervous system. The reference standard for Nocardia species identification is molecular biology, and the preferred method for antibiotic susceptibility testing (AST) is broth microdilution. Monotherapy seems appropriate for patients with primary skin nocardiosis or non-severe pulmonary disease; we reserve a multidrug regimen for more severe infections. Species identification and AST results are often missing at initiation of antibiotics. Trimethoprim-sulfamethoxazole is the preferred agent for initial therapy, because Nocardia is very often susceptible to this agent, and because it has been the keystone of nocardiosis treatment for years. Linezolid, to which Nocardia is almost always susceptible, may be an alternative. When combination therapy is required, the repertoire of companion drugs includes third-generation cephalosporins, amikacin and imipenem. Therapeutic modifications should take into account clinical response to initial therapy and AST results. Treatment duration of 6 months is appropriate for most situations, but longer durations are preferred for disseminated nocardiosis and shorter durations are reasonable in low-risk situations. Secondary prophylaxis may be considered in selected individuals with permanent immunosuppression.

IMPLICATIONS

We hereby provide the clinician with an easy-to-use algorithm for the management of individuals with nocardiosis. We also illuminate gaps in evidence and suggest future research directions.