Cryptococcus neoformans empyema in a patient receiving ibrutinib for diffuse large B-cell lymphoma and a review of the literature

Cryptococcosis Associated With Biologic Therapy: A Narrative Review

Cryptococcus is an opportunistic fungal pathogen that can cause disseminated infection with predominant central nervous system involvement in patients with compromised immunity. Biologics are increasingly used in the treatment of neoplasms and autoimmune/inflammatory conditions and the prevention of transplant rejection, which may affect human defense mechanisms against cryptococcosis. In this review, we comprehensively investigate the association between cryptococcosis and various biologics, highlighting their risks of infection, clinical manifestations, and clinical outcomes. Clinicians should remain vigilant for the risk of cryptococcosis in patients receiving biologics that affect the Th1/macrophage activation pathways, such as tumor necrosis factor α antagonists, Bruton tyrosine kinase inhibitors, fingolimod, JAK/STAT inhibitors (Janus kinase/signal transducer and activator of transcription), and monoclonal antibody against CD52. Other risk factors-such as age, underlying condition, and concurrent immunosuppressants, especially corticosteroids-should also be taken into account during risk stratification.

Isolated cryptococcal pleural effusion in a heart transplant recipient: A case report and literature review of pleural fluid adenosine deaminase levels

Isolated cryptococcal pleural effusion is rare as the initial clinical presentation in opportunistic cryptococcal infection. We describe a 59-year-old male heart transplantation recipient who presented with a mononuclear-leukocyte-predominant exudative pleural effusion, with adenosine deaminase levels (ADA) of 37 IU/L and focal pleural nodularity on computed tomography. A thorough evaluation, including pleural fluid culture, cryptococcal antigen, and histological examination, led to the diagnosis of cryptococcal pleural effusion. Antifungal therapy with fluconazole of 400 mg/day showed clinical and radiological improvement. A literature review identified six cases of cryptococcal pleural effusion that reported pleural fluid ADA levels. All cases, including the present one, involved immunocompromised hosts and exhibited a mononuclear-leukocyte-predominant exudate. High pleural fluid ADA levels were observed in approximately half of these cases. The pleural fluid cryptococcal antigen test was an important diagnostic tool for early diagnosis. In an era where immunocompromised hosts are increasing, cryptococcal infection should be considered as a potential aetiology in immunosuppressed patients with an exudative pleural effusion of unknown cause, even if ADA levels are elevated.

Disseminated Cryptococcal Disease in A Patient With Chronic Chylothorax and a Pleurovenous Catheter, a Case Report With Autopsy Findings

Cryptococcus species are ubiquitous in the environment with a global distribution. While causing disease predominantly in immunocompromised hosts such as those with advanced HIV, HIV-uninfected patients are increasingly recognized as being affected. The most common forms of infection are cryptococcal pneumonia and meningitis. HIV-uninfected patients and extrapulmonary infections have worse outcomes, likely due to delayed diagnosis and treatment. Cryptococcus infections involving chylothorax or chyloabdomen have rarely been reported in humans. We describe a case of fulminant disseminated cryptococcosis with fungemia, peritonitis, and empyema in a patient with chronic chylothorax treated with an indwelling pleurovenous shunt. Key autopsy findings included cryptococcal organisms identified on calcified lymphadenopathy, pleural adhesions, and pericardium. We discuss the importance of identifying patients with nontraditional risks factors for cryptococcal disease, such as lymphopenia and hypogammaglobulinemia, and the potential implications of pleurovenous catheters in Cryptococcus dissemination.

A Multicenter, Longitudinal Cohort Study of Cryptococcosis in Human Immunodeficiency Virus-negative People in the United States

BACKGROUND

Cryptococcosis is increasingly recognized in people without human immunodeficiency virus (HIV).

METHODS

A multicenter, prospective cohort study was performed in 25 US centers. Consenting patients were prospectively followed for ≤2 years. Neurological morbidities were assessed with longitudinal event depiction and functional scores (Montreal Cognitive Assessment [MoCA]). Risks of death were analyzed using Cox regression.

RESULTS

One hundred forty-five subjects were enrolled. Most were male (95; 65.5%) and had immunosuppression (120; 82.8%), including solid organ transplant (SOT; 33.8%), autoimmunity (15.9%), and hematologic malignancies (11.7%). Disease involved the central nervous system (CNS) in 71 subjects (49%). Fever was uncommon, documented in 40 (27.8%) subjects, and absence was associated with diagnostic delay (mean: 48.2 vs 16.5 days; P = .007). Abnormal MoCA scores (<26) were predictive of CNS disease; low scores (<22) were associated with poor long-term cognition. Longitudinal event depiction demonstrated frequent complications in people with CNS disease; 25 subjects (35.2%) required >1 lumbar puncture and 8 (11.3%) required ventriculostomies. In multivariable models, older age (>60 years) was associated with higher risks of death (hazard ratio [HR], 2.14; 95% confidence interval [CI], 1.05-4.38; P = .036), and lower risks were noted with underlying hematologic malignancy (HR, 0.29; 95% CI, 0.09-0.98; P = .05) and prior SOT (HR, 0.153; 95% CI, 0.05-0.44; P = .001).

CONCLUSIONS

Despite aggressive antifungal therapies, outcomes of CNS cryptococcosis in people without HIV are characterized by substantial long-term neurological sequelae. Studies are needed to understand mechanism(s) of cognitive decline and to enable better treatment algorithms.

Disseminated Cryptococcosis in a Patient With Metastatic Prostate Cancer Who Died in the Coronavirus Disease 2019 (COVID-19) Outbreak

We report the case of a 61-year-old patient with a history of prostate cancer affected by bone metastasis. He presented to our attention for ulcerous and necrotic cutaneous lesions unresponsive to antibiotics. The spread of cutaneous lesions and the onset of neurological symptoms suggested a cryptococcal disease, which was confirmed by lumbar puncture and cutaneous biopsy. We present the diagnostic and therapeutic approach to this case.

Fungal immunology in clinical practice: Magical realism or practical reality?

Invasive fungal infections (IFIs) occur predominantly in immunocompromised individuals but can also be seen in previously well persons. The human innate immune system recognizes key components of the fungal cell wall as foreign resulting in a myriad of signaling cascades. This triggers release of antifungal molecules as well as adaptive immune responses, which kill or at least contain the invading fungi. However, these defences may fail in hosts with primary or secondary immunodeficiencies resulting in IFIs. Knowledge of a patient's immune status enables the clinician to predict the fungal infections most likely to occur. Moreover, the occurrence of an opportunistic mycosis in a patient without known immunocompromise usually should prompt a search for an occult immune defect. A rapidly expanding number of primary and secondary immunodeficiencies associated with mycoses has been identified. An investigative approach to determining the nature of these immunodeficiencies is suggested to help guide clinicians encountering patients with IFI. Finally, promising adjunctive immunotherapy measures are currently being investigated in IFI.

Invasive fungal infections in the immunocompromised host: Mechanistic insights in an era of changing immunotherapeutics

The use of cytotoxic chemotherapy in the treatment of malignant and inflammatory disorders is beset by considerable adverse effects related to nonspecific cytotoxicity. Accordingly, a mechanistic approach to therapeutics has evolved in recent times with small molecular inhibitors of intracellular signaling pathways involved in disease pathogenesis being developed for clinical use, some with unparalleled efficacy and tolerability. Nevertheless, there are emerging concerns regarding an association with certain small molecular inhibitors and opportunistic infections, including invasive fungal diseases. This is perhaps unsurprising, given that the molecular targets of such agents play fundamental and multifaceted roles in orchestrating innate and adaptive immune responses. Nevertheless, some small molecular inhibitors appear to possess intrinsic antifungal activity and may therefore represent novel therapeutic options in future. This is particularly important given that antifungal resistance is a significant, emerging concern. This paper is a comprehensive review of the state-of-the-art in the molecular immunology to fungal pathogens as applied to existing and emerging small molecular inhibitors.

Fungal Infections with Ibrutinib and Other Small-Molecule Kinase Inhibitors

Purpose of review

Small molecule kinase inhibitors (SMKIs) have revolutionized the management of malignant and autoimmune disorders. Emerging clinical reports point toward an increased risk for invasive fungal infections (IFIs) in patients treated with certain SMKIs. In this mini-review, we highlight representative examples of SMKIs that have been associated with or are expected to give rise to IFIs.

Recent findings

The clinical use of the Bruton's tyrosine kinase inhibitor ibrutinib as well as other FDA-approved SMKIs has been associated with IFIs. The fungal infection susceptibility associated with the clinical use of certain SMKIs underscores their detrimental effects on innate and adaptive antifungal immune responses.

Summary

The unprecedented development and clinical use of SMKIs is expected to give rise to an expansion of iatrogenic immunosuppressive factors predisposing to IFIs (and other opportunistic infections). Beyond increased clinical surveillance, better understanding of the pathogenesis of SMKI-associated immune dysregulation should help devising improved risk stratification and prophylaxis strategies in vulnerable patients.

Invasive aspergillosis complicating treatment with tyrosine kinase inhibitors

We describe three cases of pulmonary aspergillosis (PA) in three patients without traditional risk factors for invasive aspergillosis infection, such as prolonged neutropenia or high dose systemic corticosteroid therapy. All three patients developed PA while taking tyrosine kinase inhibitors (TKI) and sustained greater clinical improvement once TKI were withdrawn. Our case series supports the theory TKI treatment can increase susceptibility to PA without causing neutropenia. Recognition that TKI treatment may predispose to invasive aspergillosis will allow for rapid recognition of affected patients and more effective management of future cases.