Belatacept and mediastinal histoplasmosis in a kidney transplant patient

Clinical Characteristics and Outcomes of Endemic Mycoses After Solid Organ Transplantation: A Comprehensive Review

Background

Geographically endemic fungi can cause significant disease among solid organ transplant (SOT) recipients. We provide an update on the epidemiology, clinical presentation, and outcomes of 5 endemic mycoses in SOT recipients.

Methods

Multiple databases were reviewed from inception through May 2023 using key words for endemic fungi (eg, coccidioidomycosis or Coccidioides, histoplasmosis or Histoplasma, etc). We included adult SOT recipients and publications in English or with English translation.

Results

Among 16 cohort studies that reported on blastomycosis (n = 3), coccidioidomycosis (n = 5), histoplasmosis (n = 4), and various endemic mycoses (n = 4), the incidence rates varied, as follows: coccidioidomycosis, 1.2%-5.8%; blastomycosis, 0.14%-0.99%; and histoplasmosis, 0.4%-1.1%. There were 204 reports describing 268 unique cases of endemic mycoses, including 172 histoplasmosis, 31 blastomycosis, 34 coccidioidomycosis, 6 paracoccidioidomycosis, and 25 talaromycosis cases. The majority of patients were male (176 of 261 [67.4%]). Transplanted allografts were mostly kidney (192 of 268 [71.6%]), followed by liver (n = 39 [14.6%]), heart (n = 18 [6.7%]), lung (n = 13 [4.9%]), and combined kidney-liver and kidney-pancreas (n = 6 [2.7%]). In all 5 endemic mycoses, most patients presented with fever (162 of 232 [69.8%]) and disseminated disease (179 of 268 [66.8%]). Cytopenias were frequently reported for histoplasmosis (71 of 91 [78.0%]), coccidioidomycosis (8 of 11 [72.7%]) and talaromycosis (7 of 8 [87.5%]). Graft loss was reported in 12 of 136 patients (8.8%). Death from all-causes was reported in 71 of 267 (26.6%); half of the deaths (n = 34 [50%]) were related to the underlying mycoses.

Conclusions

Endemic mycoses commonly present with fever, cytopenias and disseminated disease in SOT recipients. There is a relatively high all-cause mortality rate, including many deaths that were attributed to endemic mycoses.

Cryptococcus neoformans, a global threat to human health

BACKGROUND

Emerging fungal pathogens pose important threats to global public health. The World Health Organization has responded to the rising threat of traditionally neglected fungal infections by developing a Fungal Priority Pathogens List (FPPL). Taking the highest-ranked fungal pathogen in the FPPL, Cryptococcus neoformans, as a paradigm, we review progress made over the past two decades on its global burden, its clinical manifestation and management of cryptococcal infection, and its antifungal resistance. The purpose of this review is to drive research efforts to improve future diagnoses, therapies, and interventions associated with fungal infections.

METHODS

We first reviewed trends in the global burden of HIV-associated cryptococcal infection, mainly based on a series of systematic studies. We next conducted scoping reviews in accordance with the guidelines described in the Preferred Reporting Items for Systematic Reviews and Meta-analyses extension for Scoping Reviews using PubMed and ScienceDirect with the keyword Cryptococcus neoformans to identify case reports of cryptococcal infections published since 2000. We then reviewed recent updates on the diagnosis and antifungal treatment of cryptococcal infections. Finally, we summarized knowledge regarding the resistance and tolerance of C. neoformans to approved antifungal drugs.

RESULTS

There has been a general reduction in the estimated global burden of HIV-associated cryptococcal meningitis since 2009, probably due to improvements in highly active antiretroviral therapies. However, cryptococcal meningitis still accounts for 19% of AIDS-related deaths annually. The incidences of CM in Europe and North America and the Latin America region have increased by approximately two-fold since 2009, while other regions showed either reduced or stable numbers of cases. Unfortunately, diagnostic and treatment options for cryptococcal infections are limited, and emerging antifungal resistance exacerbates the public health burden.

CONCLUSION

The rising threat of C. neoformans is compounded by accumulating evidence for its ability to infect immunocompetent individuals and the emergence of antifungal-resistant variants. Emphasis should be placed on further understanding the mechanisms of pathogenicity and of antifungal resistance and tolerance. The development of novel management strategies through the identification of new drug targets and the discovery and optimization of new and existing diagnostics and therapeutics are key to reducing the health burden.

Opportunistic infections after conversion to belatacept in kidney transplantation

BACKGROUND

Belatacept (bela) rescue therapy seems to be a valuable option for calcineurin inhibitor chronic toxicity in kidney transplantation. Nevertheless, the risk of infection associated with bela is not well reported.

METHODS

We report the rate of opportunistic infections (OPI) after a switch to bela in a multicentric cohort of 280 kidney transplant patients.

RESULTS

Forty-two OPI occurred in 34 patients (12.1%), on average 10.8 ± 11.3 months after the switch. With a cumulative exposure of 5128 months of bela treatment, we found an incidence of 0.008 OPI/month of exposure, and 9.8 OPI/100 person-years. The most common OPI was cytomegalovirus (CMV) disease in 18/42 OPI (42.9%) and pneumocystis pneumonia in 12/42 OPI (28.6%). Two patients presented a progressive multifocal leucoencephalopathy and two patients developed a cerebral Epstein-Barr virus-induced post-transplant lymphoproliferative disease. OPI led to death in 9/34 patients (26.5%) and graft failure in 4/34 patients (11.8%). In multivariate analysis, estimated glomerular filtration rate <25/mL/min/1.73 m2 on the day of the switch and the use of immunosuppressive agents before transplantation were associated with the occurrence of OPI. We found a higher rate of infection-related hospitalization (24.1 versus 12.3/100 person-years, P = 0.0007) and also a higher rate of OPI (13.2 versus 6.7/100 person-years, P = 0.005) in the early conversion group (within 6 months).

CONCLUSIONS

The risk of OPI is significant post-conversion to bela and may require additional monitoring and prophylactic therapy, particularly regarding pneumocystis pneumonia and CMV disease. These data need to be confirmed in a larger case-control study.

Fungal Infections Potentiated by Biologics

Biologic therapies including monoclonal antibodies, tyrosine kinase inhibitors, and other agents represent a notable expansion in the pharmacotherapy armamentarium in treatment of a variety of diseases. Many of these therapies possess direct or indirect immunosuppressive and immunomodulatory effects, which have been associated with bacterial, viral, and fungal opportunistic infections. Careful screening of baseline risk factors before initiation, targeted preventive measures, and vigilant monitoring while on active biologic therapy mitigate these risks as use of biologics becomes more commonplace. This review compiles reported evidence of fungal infections associated with these agents with a focus on the tumor necrosis factor-α inhibitor class.

Histoplasmosis in transplant recipients

Histoplasma capsulatum is a dimorphic fungus that most often causes asymptomatic infection in the immunocompetent population. In immunocompromised patients, including solid organ transplant (SOT) and hematopoietic cell transplant (HCT) recipients, however, it is likely to cause severe life-threatening infection. Post-transplant histoplasmosis (PTH) in SOT is uncommon with an incidence of ≤1% and is even rarer in HCT patients. The majority of PTH in SOT is diagnosed in the first 2 years following transplantation. Histoplasmosis may result from endogenous reactivation of latent infection, de novo post-transplant acquisition, and donor-derived infection. Disseminated infection is common. Fever is the most common symptom and clinical features are often nonspecific, but patients with disseminated infection may present with a septic picture. Other features, including pancytopenia and hepatosplenomegaly, may not be prominent early in the course of illness. Contemporary histoplasma antigen assays are the most sensitive tests but cross-reactivity with antigens of other fungi, including with Aspergillus galactomannan, is not uncommon. Treatment should be continued for at least a year. Histoplasma antigen levels have prognostic value and can be used to monitor the response to therapy. The attributable mortality is approximately 10%. Routine screening of donors and recipients is not currently recommended.