Fungal infection in post-renal transplant patient: Single-center experience

Talaromyces marneffei: A challenging diagnosis in a kidney transplant patient

Key Clinical Message

In addition to post-transplant lymphoproliferative disorders, it is necessary to be alert to the drug-resistant bacteria or fungal infection, especially Talaromyces marneffei, in kidney transplant patients who have failed antibiotic treatment and whose PET-CT indicates high metabolic mass in the transplanted kidney with a large number of other organs and lymph nodes.

Abstract

Talaromyces marneffei (TM) is a rare pathogenic fungus that primarily affects individuals with compromised immune systems. Post-transplant lymphoproliferative disorders (PTLD) are serious complications that can occur after solid organ and cell transplantation. Both TM infection and PTLD can invade the monocyte-macrophage system and often manifest as extranodal masses. This case report describes a kidney transplant patient who presented with symptoms of frequent, urgent, and painful urination over 6 months. Pulmonary CT scans revealed multiple nodules, and PET-CT demonstrated enlarged lymph nodes in the lungs and the transplanted kidney. The clinical manifestations closely mimicked those of PTLD. The confirmation of TM was achieved through pathogen metagenomic next-generation sequencing and renal biopsy. Unfortunately, despite receiving treatment with antifungal agents, anti-infective therapy, the patient's condition did not respond favorably, ultimately resulting in their unfortunate demise due to COVID-19.

COVID-19-Associated Rhino-Orbito-Cerebral Mucormycosis: A Single Tertiary Care Center Experience of Imaging Findings With a Special Focus on Intracranial Manifestations and Pathways of Intracranial Spread

Background and objective The COVID-19 pandemic and mucormycosis epidemic in India made research on the radiological findings of COVID-19-associated mucormycosis imperative. This study aims to describe the imaging findings in COVID-19-associated mucormycosis, with a special focus on the intracranial manifestations.  Methodology Magnetic resonance imaging (MRI) scans of all patients with laboratory-proven mucormycosis and post-COVID-19 status, for two months, at an Indian Tertiary Care Referral Centre, were retrospectively reviewed, and descriptive statistical analysis was carried out. Results A total of 58 patients (47 men, 81%, and 11 women, 19%) were evaluated. Deranged blood glucose levels were observed in 47 (81%) cases. The intracranial invasion was detected in 31 (53.4%) patients. The most common finding in cases with intracranial invasion was pachymeningeal enhancement (28/31, 90.3%). This was followed by infarcts (17/31, 55%), cavernous sinus thrombosis (11/58, 18.9%), fungal abscesses (11/31, 35.4%), and intracranial hemorrhage (5/31, 16.1% cases). The perineural spread was observed in 21.6% (11/51) cases. Orbital findings included extraconal fat and muscle involvement, intraconal involvement, orbital apicitis, optic neuritis, panophthalmitis, and orbital abscess formation in decreasing order of frequency. Cohen's kappa coefficient of interrater reliability for optic nerve involvement and cavernous sinus thrombosis was 0.7. Cohen's coefficient for all other findings was 0.8-0.9. Conclusions COVID-19-associated rhino-orbito-cerebral mucormycosis has a plethora of orbital and intracranial manifestations. MRI, with its superior soft-tissue resolution and high interrater reliability, as elucidated in this study, is the imaging modality of choice for expediting the initial diagnosis, accurately mapping out disease extent, and promptly identifying and scrupulously managing its complications.

Cryptococcosis in kidney transplant recipients: Current understanding and practices

Cryptococcosis is the third most commonly occurring invasive fungal disease in solid organ transplant recipients (SOT). It is caused by encapsulated yeast, Cryptococcus species, predominantly Cryptococcus neoformans and Cryptococcus gattii. Though kidney transplant recipients are at the lowest risk of cryptococcosis when compared to other solid organ transplant recipients such as lung, liver or heart, still this opportunistic infection causes significant morbidity and mortality in this subset of patients. Mortality rates with cryptococcosis range from 10%-25%, while it can be as high as 50% in SOT recipients with central nervous system involvement. The main aim of diagnosis is to find out if there is any involvement of the central nervous system in disseminated disease or whether there is only localized pulmonary involvement as it has implications for both prognostication and treatment. Detection of cryptococcal antigen (CrAg) in cerebrospinal fluid or plasma is a highly recommended test as it is more sensitive and specific than India ink and fungal cultures. The CrAg lateral flow assay is the single point of care test that can rapidly detect cryptococcal polysaccharide capsule. Treatment of cryptococcosis is challenging in kidney transplant recipients. Apart from the reduction or optimization of immunosuppression, lipid formulations of amphotericin B are preferred as induction antifungal agents. Consolidation and maintenance are done with fluconazole; carefully monitoring its interactions with calcineurin inhibitors. This review further discusses in depth the evolving developments in the epidemiology, pathogenesis, diagnostic assays, and management approach of cryptococcosis in kidney transplant recipients.

Immunosuppressive Therapy and Nutritional Status of Patients after Kidney Transplantation: A Protocol for a Systematic Review

(1) Background: Kidney transplantation is widely recognized as the most effective method of treating end-stage renal disease. Immunosuppressive therapy plays a pivotal role in the treatment of kidney transplant patients, encompassing all patients (except identical twins), and is administered from organ transplantation until the end of its function. The aim of this systematic review is to identify the evidence of the association between immunosuppressive therapy and nutritional status of patients following kidney transplantation. (2) Methods: This protocol has been designed in line with Preferred Items for Systematic Reviews (PRISMA-P). Our search encompasses several databases, including MEDLINE (via PubMed), EMBASE (Elsevier), Scopus and Web of Science. We intend to include observational studies (cross-sectional, case-control, and cohort designs), randomized controlled trials (RCTs), as well as completed and ongoing non-randomized study designs. We will confine our search to studies published in English within the past decade (from inception to 17 February 2023). Qualitative studies, case studies, and conference reports will be excluded. The selection process will be done in Covidence by two independent reviewers. Data extraction will be conducted using a standardized MS Excel template version 16.0. Quality assessment of included studies will be performed using the Cochrane Risk of Bias tool for randomized trials (RoB2), or the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool. Risk-of-bias plots will be generated using the web application Robvis. Relevant data that have been extracted from eligible studies will be presented in a narrative synthesis. We expect the studies to be too heterogeneous to perform subgroup analyses. (3) Conclusion: This systematic review will offer insights into the evidence regarding association between immunosuppressive therapy and nutritional status of adult patients (18 years of age or older) within the initial year following kidney transplantation. To our knowledge, there is no systematic review addressing that question.

Brain abscess following kidney transplantation: A single centre observational study from North India

Background

Amongst the infections in kidney transplant recipients, brain abscess represents an uncommon life-threatening complication. Mortality continues to be high despite improvements in diagnostics and therapeutics.

Method

We conducted an observational study, describing the incidence, presentation, implicating pathogen, management and outcome of brain abscess following kidney transplantation at our centre.

Result

Amongst the 1492 patients who underwent kidney transplantation at our centre between June 1991 and January 2023 (cumulative follow-up: 4936 patient-years), five females and four males, developed brain abscesses. The incidence proportion (risk) is 0.6% with an incidence rate of 6.03 cases per 1000 patient years. The median duration from transplant to development of brain abscess was 5 weeks (range: 4 weeks to 9 years). The commonest presentation was a headache. A definitive microbiological diagnosis was established in eight out of nine patients. The commonest implicated organism was a dematiaceous fungus, Cladophialophora bantiana (3 patients, 33.3%). Despite the reduction in immunosuppression, surgical evacuation and optimal medical therapy, five (55.55%) patients succumbed to their illness.

Conclusions

Brain abscesses following kidney transplantation is an uncommon, life-threatening condition. It usually occurs in the early post-transplant period and the presentation is often subtle. Unlike immunocompetent individuals, a fungus is the most common causative organism in those with solid organ transplants. The management includes a reduction in immunosuppression, early antimicrobial therapy, and surgical decompression.

South Asian Transplant Infectious Disease Guidelines for Solid Organ Transplant Candidates, Recipients, and Donors

These guidelines discuss the epidemiology, screening, diagnosis, posttransplant prophylaxis, monitoring, and management of endemic infections in solid organ transplant (SOT) candidates, recipients, and donors in South Asia. The guidelines also provide recommendations for SOT recipients traveling to this region. These guidelines are based on literature review and expert opinion by transplant physicians, surgeons, and infectious diseases specialists, mostly from South Asian countries (India, Pakistan, Bangladesh, Nepal, and Sri Lanka) as well as transplant experts from other countries. These guidelines cover relevant endemic bacterial infections (tuberculosis, leptospirosis, melioidosis, typhoid, scrub typhus), viral infections (hepatitis A, B, C, D, and E; rabies; and the arboviruses including dengue, chikungunya, Zika, Japanese encephalitis), endemic fungal infections (mucormycosis, histoplasmosis, talaromycosis, sporotrichosis), and endemic parasitic infections (malaria, leishmaniasis, toxoplasmosis, cryptosporidiosis, strongyloidiasis, and filariasis) as well as travelers' diarrhea and vaccination for SOT candidates and recipients including travelers visiting this region. These guidelines are intended to be an overview of each topic; more detailed reviews are being published as a special supplement in the Indian Journal of Transplantation .

Role of Fine Needle Aspiration Cytology in the Rapid Diagnosis of Pulmonary Infections in Renal Allograft Recipients with Respiratory Failure

Background

Renal transplantation is the treatment of choice in patients with end-stage renal disease. However, allograft recipients are at a higher risk of infection due to immunosuppressive therapies. This study aimed to analyze the utility of fine needle aspiration cytology (FNAC) lung in the etiological diagnosis of pulmonary infections in renal allograft recipients with respiratory failure.

Materials and Methods

This is a retrospective study done in post-renal transplant patients presenting with pulmonary infections and respiratory failure in the past 7 years, in whom image-guided lung FNAC was done for diagnosis.

Results

A total of 35 renal allograft recipients presenting with respiratory failure and having focal or diffuse pulmonary opacities (lesions) on radiological imaging were subjected to lung FNAC. The mean age of the patients was 41.1 ± 11.8 years (range 19-72), with the majority being males (n = 28, 80%); six (17.1%) of them were on invasive ventilation. The diagnostic yield of FNAC in our cohort was 77.1% (27 out of 35). Microorganisms were isolated in 21 cases (60%), with Nocardia being the most common (nine cases, 25.7%), Mycobacterial tuberculosis identified in six patients (17.1%), Aspergillus in three (8.6%), and one (2.9%) each had atypical Mycobacterium, zygomycetes, and Cryptococcus. FNAC suggested viral cytopathic effect in five patients, and cytomegalovirus (CMV) quantitative polymerase chain reaction test was found positive in four of these. One case was diagnosed as adenocarcinoma lung.

Conclusion

Lung FNAC is a useful for establishing the etiological diagnosis of pulmonary lesions in renal transplant patients with respiratory failure.

Current Status Regarding Immunosuppressive Treatment in Patients after Renal Transplantation

Renal transplantation is now the best treatment for end-stage renal failure. To avoid rejection and prolong graft function, organ recipients need immunosuppressive therapy. The immunosuppressive drugs used depends on many factors, including time since transplantation (induction or maintenance), aetiology of the disease, and/or condition of the graft. Immunosuppressive treatment needs to be personalised, and hospitals and clinics have differing protocols and preparations depending on experience. Renal transplant recipient maintenance treatment is mostly based on triple-drug therapy containing calcineurin inhibitors, corticosteroids, and antiproliferative drugs. In addition to the desired effect, the use of immunosuppressive drugs carries risks of certain side effects. Therefore, new immunosuppressive drugs and immunosuppressive protocols are being sought that exert fewer side effects, which could maximise efficacy and reduce toxicity and, in this way, reduce both morbidity and mortality, as well as increase opportunities to modify individual immunosuppression for renal recipients of all ages. The aim of the current review is to describe the classes of immunosuppressive drugs and their mode of action, which are divided by induction and maintenance treatment. An additional aspect of the current review is a description of immune system activity modulation by the drugs used in renal transplant recipients. Complications associated with the use of immunosuppressive drugs and other immunosuppressive treatment options used in kidney transplant recipients have also been described.

Biopsy-proven fungal pyelonephritis complicating delayed graft function in a renal transplant patient

Delayed graft function (DGF) is a common phenomenon following renal transplantation, which can be due to several factors. A rare cause includes invasive fungal infections, which can often be a challenge to diagnose. Nonetheless, prompt identification of such infections particularly within transplant patients is essential as they can lead to severe downstream sequelae, including graft loss and even death. We describe here a challenging case of fungal pyelonephritis complicating and potentially leading to DGF and further dialysis dependence within a renal transplant patient. Notably, we highlight the importance and clinical utility of biopsy to confirm the diagnosis, as investigations may be largely normal otherwise. Furthermore, we emphasise that with early identification of these infections, effective antifungal treatment can be commenced in a timely fashion leading to better patient outcomes and good graft function.

Epidemiology of Invasive Fungal Infections in Solid Organ Transplant Recipients: an Indian Perspective

Purpose of Review

This review summarizes the available Indian data on epidemiology of invasive fungal infections (IFI) in recipients of solid organ transplants (SOT). The epidemiology is further compared with studies from other parts of the world for each SOT type.

Recent Findings

The available studies on Indian epidemiology of IFI in SOT are scarce, though the number of SOTs performed in India have increased tremendously in recent years. The limited data from India present a distinct spectrum of infection in transplant recipients with high incidence of mucormycosis. During COVID-19 outbreak, IFI rate increased and renal transplant recipients acquired mucormycosis earlier than previous studies.

Summary

Maximum data on IFI was available from renal transplant recipients, wherein mucormycosis was the predominant IFI in Indian patients in contrast to invasive candidiasis in majority countries. The other IFIs had varied spectrum. With the increasing number of SOTs being performed and the already persisting high burden of IFI in India, there is an urgent need of larger prospective studies on epidemiology of IFI in transplant recipients.

Comprehensive analysis of peripheral blood non-coding RNAs identifies a diagnostic panel for fungal infection after transplantation

The occurrence of fungal infection seriously affects the survival and life quality of transplanted patients. The accurate diagnosis is of particular importance in the early stage of infection. To develop a novel diagnostic method for this kind of patient, we established a post-transplant immunosuppressed mice model with fungus inoculation and collected their peripheral blood at specific time points after infection. After screening by microarray, differentially expressed miRNAs and lncRNAs were selected and homologously analyzed with those of human beings from the gene database. These miRNAs and lncRNAs candidates were validated by qRT-PCR in peripheral blood samples from transplanted patients. We found that, compared with normal transplanted patients, the levels of miR-215 and miR-let-7 c were up-regulated in the plasma of patients with fungal infection (P < 0.01), while levels of miR-154, miR-193a, NR_027669.1, and NR_036506.1 were down-regulated in their peripheral blood mononuclear cells (P < 0.01). Principal component analysis shows that the expression pattern of the above RNAs was different between the two groups. A 6-noncoding-RNA detection panel was established by the support vector machine analysis, whose area under the ROC curve was 0.927. The accuracy, precision, sensitivity, and specificity of this model were 0.928, 0.919, 0.944, and 0.910, respectively. Though our detection panel has excellent diagnostic efficacy, its clinical application value still needs to be further confirmed by multi-center prospective clinical trials.

Risk factors and outcomes of COVID associated mucormycosis in kidney transplant recipients

BACKGROUND

Invasive Mucormycosis (IM) is a life-threatening fungal infections occurring mostly in solid organ transplant (SOT)recipients, patients with haematological malignancies, and diabetes. A sudden spurt of mucormycosis has been reported in severe acute respiratory syndrome coronavirus-2 (SARS-COV2) pandemic in India, however there is little data about Coronavirus disease 2019 (COVID -19) associated mucormycosis (CAM) in kidney transplant recipients (KTRs).

METHODS

We describe the clinical presentations, risk factors, treatment and outcomes of 11 mucormycosis cases in Kidney transplant recipients (KTRs) post COVID 19 infection from February 2020 to June 2021 at a single centre in India.

RESULTS

Mucormycosis was seen in 11/102 (10.7%) KTRs during the pandemic. Six patients had mild disease and rest five had moderate disease. Seven patients had pre-existing diabetes mellitus and four developed new onset hyperglycemia after receiving steroids for COVID-19 infection. All had poorly controlled sugars at the time of presentation. Most common presentation was Rhino-orbital-cerebral mucormycosis (ROCM) in 10/11 (89%) patients and one ha pulmonary mucormycosis. All patients received combination of Amphotericin B and surgical debridement/excision of affected tissue followed by Posaconazole prophylaxis. Nine patients recovered, however two patient succumbed to their illness after median of 14(7-21) days from diagnosis. One patient developed acute T cell mediated rejection during the course of recovery. At last follow up, the mean serum creatinine was 2.05 mg/dl as compared to 1.4 mg/dl at presentation.

CONCLUSIONS

Invasive Mucormycosis is a common fungal infection in transplant recipients in India after COVID-19.Early diagnosis and prompt treatment with combination of surgical debridement and liposomal amphotericin B are key to better outcomes in COVID associated mucormycosis. Judicious use of steroids and control of hyperglycemia is key to avoid flaring up of the fungal infection. This article is protected by copyright. All rights reserved.

Immune-mediated membranous nephropathy: Long term fluconazole usage caused podocyte autophagy

The primary consequences of membranous nephropathy (MN) are the development of nephrotic syndrome including hypogammaglobulinemia, the increased infectious risk, the loss of protein-bound vitamin D, and, above all, an elevated thromboembolic incidence of up to 50% in severe proteinuria patients. Membrane nephropathy may be either idiopathic or primary, not recognized (70%-80%) or secondary (20%-30%) to pathological sicknesses such as hepatitis B, systemic lupus erythematosus, malignancies, and side-effects of medicines. The immunological responses in MN involve multiple components: immunoglobulin G (IgG), long-escaped antigens, and the membrane attachment complex, formed by the supplement to form C5b-9. In general, IgG4 is the most significant IgG subclass deposited in idiopathic membranous nephropathic disease but fluctuating IgG1 levels also are linked with immunological deposits. In contrast, IgG1, IgG2, and IgG3 deposition are greater than IgG4 deposition in secondary nephropathy. Fluconazole is a synthetic antifungal triazole that is often used. It is well tolerated in general and has never been identified as a cause of nephropathies. We report on the development of MN caused by fluconazole therapy that could potentiate podocyte autophagy.

Epidemiology of Mucormycosis in India

Mucormycosis is an angioinvasive disease caused by saprophytic fungi of the order Mucorales. The exact incidence of mucormycosis in India is unknown due to the lack of population-based studies. The estimated prevalence of mucormycosis is around 70 times higher in India than that in global data. Diabetes mellitus is the most common risk factor, followed by haematological malignancy and solid-organ transplant. Patients with postpulmonary tuberculosis and chronic kidney disease are at additional risk of developing mucormycosis in this country. Trauma is a risk factor for cutaneous mucormycosis. Isolated renal mucormycosis in an immunocompetent host is a unique entity in India. Though Rhizopus arrhizus is the most common etiological agent of mucormycosis in this country, infections due to Rhizopus microsporus, Rhizopus homothallicus, and Apophysomyces variabilis are rising. Occasionally, Saksenaea erythrospora, Mucor irregularis, and Thamnostylum lucknowense are isolated. Though awareness of the disease has increased among treating physicians, disease-associated morbidity and mortality are still high, as patients seek medical attention late in the disease process and given the low affordability for therapy. In conclusion, the rise in the number of cases, the emergence of new risk factors and causative agents, and the challenges in managing the disease are important concerns with mucormycosis in India.