Invasive aspergillosis with pulmonary and central nervous system involvement during ibrutinib therapy for relapsed chronic lymphocytic leukaemia: case report

Acute lymphoblastic leukemia with central nervous system Aspergillus infection: A case report and literature review

Ubiquitous in nature, Aspergillus rarely invades the brain to induce infection in general. However, in clinical practice, some patients with hematological malignancies or immunosuppression may suffer from Aspergillus infection of the central nervous system, which arises most commonly as a result of hematogenous dissemination from a pulmonary focus or direct extension from the paranasal sinus infection. Treatment is clinically challenging and the mortality rate is relatively high. Recently, a case diagnosed with acute lymphocytic leukemia was admitted to the Department of Neurosurgery, The First People's Hospital of Huzhou (First Affiliated Hospital of Huzhou University, Huzhou, China). During chemotherapy, space-occupying lesions were observed in the right occipital lobe of the patient, and lesion progression was captured. After treatment with surgery, an analysis of specimens collected from the patient was performed and was suggestive of Aspergillus infection. Following the symptomatic therapy with voriconazole, the patient's disease prognosis was favorable. The focus of infection due to pulmonary aspergillosis or Aspergillus sinusitis was not detected in the patient and the focus was not a common site of hematogenous infection. In addition, the patient exhibited no obvious clinical symptoms. In view of the above observations, the possibility of hospital-acquired infection was considered, to which clinicians should be alert.

Aspergillosis of central nervous system in patients with leukemia and stem cell transplantation: a systematic review of case reports

Background

Aspergillosis of Central Nervous System (CNS) is a highly lethal infection in patients with leukemia and Stem Cell Transplantation (SCT).

Methods

Case reports of CNS aspergillosis in patients with leukemia and SCT published between 1990 and August 2020 were gathered using a structured search through PubMed/Medline.

Results

Sixty-seven cases were identified over the searches of the PubMed bibliographic database and then, 59 cases were included in the final analysis. Europe had the largest share of cases at 57.6% (34 reports), followed by Americas and Asia. Affected patients were predominantly males (58.6%) and the mean age of the patients was 36.1 years, while 62.7% of the patients were under the age of 50 years. The most common leukemia types include Acute Lymphoblastic Leukemia (ALL), Chronic Lymphocytic Leukemia (CLL), and Acute Myeloid Leukemia (AML) at 43.4%, 27.4%, and 23.5%, respectively. Furthermore, stem cell transplantation was reported in 11 cases. The overall mortality was 33%; however, the attributable mortality rate of CNS aspergillosis was 24.5%. Altered mental status, hemiparesis, cranial nerve palsies, and seizures were the clearest manifestations of infection and lung involvement reported in 57% of the patients. Histopathologic examination led to the diagnosis of infection in 57% of the patients followed by culture (23.7%), galactomannan assay (8.5%), and molecular method (3.3%). Amphotericin B and voriconazole were the most frequently used drugs for infection treatment. Good results were not obtained in one-third of the patients treated by voriconazole. Finally, neurosurgical intervention was used for 23 patients (39%).

Conclusion

CNS aspergillosis is a rapidly progressive infection in leukemic patients. Thus, these patients should be followed up more carefully. Furthermore, management of induction chemotherapy, use of different diagnostic methods, and use of appropriate antifungal can lead to infection control.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12941-021-00452-9.

Updated EUCAST Clinical Breakpoints against Aspergillus, Implications for the Clinical Microbiology Laboratory

Azole resistance poses a problem for the management of patients with invasive aspergillosis. Former species are in fact groups of closely related species (or complexes); cryptic species frequently show high antifungal resistance. The European Committee on Antimicrobial Susceptibility Testing (EUCAST) EUCAST Definitive Document (E.Def) 9.3.2 includes guidelines for antifungal susceptibility testing on Aspergillus spp. and clinical breakpoints for amphotericin B, itraconazole, voriconazole, posaconazole, and isavuconazole against A. flavus, A. fumigatus, A. nidulans, A. niger, and A. terreus. New clinical breakpoints were released in February 2020 and one of the most relevant modifications was the definition of the new "susceptible, increased exposure" (formerly "intermediate") category. Another relevant change was the adoption of the concept of area of technical uncertainty (ATU) that refers to problematic areas which involve uncertainty of susceptibility categorisation (e.g., when minimum inhibitory concentrations (MICs) for susceptible and resistant organisms overlap). To accommodate both the new "susceptible, increased exposure" category and the concept of ATU, MICs of azoles and amphotericin B that fall in the former "intermediate" category have been automatically categorized as either R (amphotericin B) or ATU (triazoles). Finally, EUCAST-AFST (Antifungal Susceptibility Testing) decided to adopt new breakpoints for less common species provided that the epidemiological cut-off value (ECOFF) is below or comparable to the breakpoint for the type species (A. fumigatus).

Azole resistance survey on clinical Aspergillus fumigatus isolates in Spain

OBJECTIVES

We aimed to assess the percentage of azole resistance in Aspergillus fumigatus in Spain.

METHODS

Thirty participating Spanish hospitals stored all morphologically identified A. fumigatus sensu lato clinical isolates-regardless their clinical significance-from 15 February to 14 May 2019. Isolates showing azole resistance according to the EUCAST 9.3.2 methodology were molecularly identified and the cyp51A gene was studied in A. fumigatus sensu stricto isolates.

RESULTS

Eight hundred and forty-seven isolates from 725 patients were collected in 29 hospitals (A. fumigatus sensu stricto (n = 828) and cryptic species (n = 19)). Isolates were mostly from the lower respiratory tract (94.0%; 797/847). Only cryptic species were amphotericin B resistant. Sixty-three (7.4%) out of the 847 isolates were resistant to ≥1 azole(s). Azole resistance was higher in cryptic species than in A. fumigatus sensu stricto (95%, 18/19 vs. 5.5%, 45/828); isavuconazole was associated to the lowest number of non-wild type isolates. The dominant mechanism of resistance was the presence of TR₃₄-L98H substitutions (n = 24 out of 63). Out of the 725 patients, 48 (6.6%) carried either cryptic species (n = 14) or A. fumigatus sensu stricto (n = 34; 4.7%) resistant isolates. Aspergillus fumigatus sensu stricto harbouring either the TR₃₄-L98H (n = 19) or TR₄₆/Y121F/T289A (n = 1) mutations were detected in patients in hospitals located at 7/24 studied cities.

DISCUSSION

Of the patients, 6.6% carry azole-resistant A. fumigatus sensu lato isolates in Spain. TR₃₄-L98H is the dominant cyp51A gene substitutions, although its presence is not widespread.

Immunomodulatory effect of ibrutinib: Reducing the barrier against fungal infections

The Bruton tyrosine kinase (BTK) inhibitor ibrutinib is increasingly used in the treatment of chronic lymphocytic leukemia (CLL). Moreover, very promising results have been reported in other B-cell malignancies, including primary central nervous system lymphoma (PCNSL). Although well-tolerated in the majority of patients, ibrutinib demonstrates in some cases troublesome toxicities, including invasive fungal infections (IFIs). In the present review, we summarize clinical manifestations of IFIs in patients treated with ibrutinib, generally characterized by an early onset, mild clinical manifestations, asymptomatic/low symptomatic pulmonary localization and high incidence of central nervous system (CNS) involvement. IFI risk appears particularly increased in patients receiving ibrutinib associated with other immune modulator agents, especially with steroids or immune-chemotherapy. Moreover, the immunomodulatory effect of ibrutinib is described, pointing the attention on the involvement of specific molecules targeted by ibrutinib in innate and adaptive response to fungal infection. Overall, the findings indicate the ibrutinib may rapidly impair innate immune cell functions, while concomitantly restoring an effective protective potential of adaptive immune compartment. A correct awareness, especially when other predisposing factors are present, is warranted about the potential risk of IFIs in ibrutinib-treated patients.

Ibrutinib-associated invasive fungal diseases in patients with chronic lymphocytic leukaemia and non-Hodgkin lymphoma: An observational study

BACKGROUND

Invasive fungal diseases (IFD) are life-threatening infections most commonly diagnosed in acute leukaemia patients with prolonged neutropenia and are uncommonly diagnosed in patients with lymphoproliferative diseases.

OBJECTIVES

Following the initial report of aspergillosis diagnosed shortly after beginning ibrutinib for chronic lymphocytic leukaemia, a survey was developed to seek additional cases of IFD during ibrutinib treatment.

METHODS

Local and international physicians and groups were approached for relevant cases. Patients were included if they met the following criteria: diagnosis of chronic lymphocytic leukaemia/non-Hodgkin lymphoma; proven or probable IFD; and ibrutinib treatment on the date IFD were diagnosed. Clinical and laboratory data were captured using REDCap software.

RESULT

Thirty-five patients with IFD were reported from 22 centres in eight countries: 26 (74%) had chronic lymphocytic leukaemia. The median duration of ibrutinib treatment before the onset of IFD was 45 days (range 1-540). Aspergillus species were identified in 22 (63%) of the patients and Cryptococcus species in 9 (26%). Pulmonary involvement occurred in 69% of patients, cranial in 60% and disseminated disease in 60%. A definite diagnosis was made in 21 patients (69%), and the mortality rate was 69%. Data from Israel regarding ibrutinib treated patients were used to evaluate a prevalence of 2.4% IFD.

CONCLUSIONS

The prevalence of IFD among chronic lymphocytic leukaemia/non-Hodgkin lymphoma patients treated with ibrutinib appears to be higher than expected. These patients often present with unusual clinical features. Mortality from IFD in this study was high, indicating that additional studies are urgently needed to identify patients at risk for ibrutinib-associated IFD.

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.

The Muddied Waters of Ibrutinib Therapy

A 37-year-old male was admitted with an atypical presentation of central nervous system (CNS) aspergillosis while on ibrutinib therapy for a CNS relapse of mantle cell lymphoma. This case highlights the importance of a high clinical suspicion of opportunistic infections in patients receiving small-molecule kinase inhibitors. This report includes a review of reported cases of Aspergillus infections in patients receiving ibrutinib and the shared features of these cases.

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.

Review of targeted therapy in chronic lymphocytic leukemia: what a radiologist needs to know about CT interpretation

The last 5 years have been marked by profound innovation in the targeted treatment of chronic lymphocytic leukemia (CLL) and indolent lymphomas. Using CLL as a case study, we present a timeline and overview of the current treatment landscape for the radiologist, including an overview of clinical and radiological features of CLL, discussion of the targeted agents themselves, and the role of imaging in response and toxicity assessment. The goal is to familiarize the radiologist with multiple Food and Drug Administration (FDA)-approved targeted agents used in this setting and associated adverse events which are commonly observed in this patient population.