Isavuconazole in a Successful Combination Treatment of Disseminated Mucormycosis in a Child with Acute Lymphoblastic Leukaemia and Generalized Haemochromatosis: A Case Report and Review of the Literature

Invasive mucormycosis in immunocompromised children is a life-threatening fungal infection. We report a case of a 7-year-old girl treated for acute lymphoblastic leukaemia complicated by disseminated mucormycosis during induction therapy. Microscopic examination of surgically removed lung tissue revealed wide, pauci-septate hyphae suggesting a Mucorales infection. This diagnosis was confirmed immunohistochemically and by PCR analysis followed by a final identification of Cunninghamella sp. The patient was treated successfully with surgical debridement and antifungal combination therapy with amphotericin B, caspofungin and isavuconazole. The use of isavuconazole in a child was not previously reported. Additionally, case reports concerning pulmonary mucormycoses in paediatric population published after 2010 were reviewed. Nineteen out of 26 identified patients suffered from haematological diseases. Reported mortality reached 38.5%. By the fact of rising morbidity, unsatisfactory results of treatment and remaining high mortality of mucormycoses in immunocompromised patients, new therapeutic options are warrant. Isavuconazole, with its broad-spectrum activity, good safety profile and favourable pharmacokinetics, is a promising drug. However, further studies are necessary to confirm positive impact of isavuconazole on mucormycosis treatment in children.

     

Posaconazole Salvage Treatment for Invasive Fungal Infection

Invasive fungal infection (IFI) is an important cause of morbidity and mortality. Posaconazole is a second generation triazole with a broad spectrum, and it may be suitable for salvage antifungal treatment although posaconazole is not usually considered to be as first-line antifungal therapy for IFI. The purpose of this study was to assess the utility of posaconazole salvage treatment for IFI. We conducted a retrospective review of patients with salvage antifungal treatment with posaconazole for IFI at our institution between December 2007 and July 2012. A total of ten patients received posaconazole salvage IFI. Etiology of IFI was consisting of mucormycosis (four patients), Paecilomyces variotii (one patient), and unspecified IFI etiology (five patients). Causes of posaconazole treatment were following; intolerance of previous antifungal therapy in five patients, refractory IFI on previous antifungal therapy in four patients, and both intolerance of previous antifungal therapy and refractory IFI on previous antifungal therapy in one patient. Duration of posaconazole salvage treatment ranged from 15 to 355 days with median 47 days. The overall successful posaconazole salvage treatment response rate was 80.0 % (8 of 10 patients). There were three patients who died during the study period. However, only one death was attributed to the progression of IFI. Two patients discontinued posaconazole due to adverse events. Posaconazole salvage treatment was effective antifungal therapy for IFI. Further studies are needed to define the optimal therapeutic strategy.     

A Case of Rhinoorbital Mucormycosis in a Leukemic Patient with a Literature Review from Turkey

Mucormycosis (Zygomycosis) is a rare, invasive, opportunistic fungal infection of the paranasal sinuses, caused by a fungus of the order Mucorales. We report a case of rhinoorbital mucormycosis caused by Rhizopus oryzae in an acute lymphoblastic leukemia patient and review the 79 Mucormycosis cases reported in the last decade from Turkey. In our case, the diagnosis was made with endoscopic appearance, computerized tomography of the paranasal sinuses, and culture of the surgical materials. Following aggressive surgical debridement and parenteral amphotericin B therapy, the patient recovered completely. In Turkish literature, rhinocerebral manifestations were the most common form of the mucormycosis (64 cases), followed by pulmonary form (6 cases). The most common risk factor was hematologic malignancies (32 cases) and diabetes mellitus (32 cases), similar to those reported from the rest of the world. The etiologic agents responsible for the review cases were Rhizopus sp., Mucor spp., Rhizomucor spp., Rhizopus oryzae, Mucor circinelloides, and Lichtheimia corymbifera. Although various treatment modalities were used, amphotericin B was the mainstay of therapy. Mortality rate was found to be 49.4% in review cases. It seems that strong clinical suspicion and early diagnosis, along with aggressive antifungal therapy and endoscopic sinus surgery, have great importance for better prognosis in mucormycosis.     

Tratamiento antifúngico individualizado en el paciente crítico con infección fúngica invasora

Invasive candidiasis (IC) is the most common invasive fungal infection (IFI) affecting critically ill patients, followed by invasive pulmonary aspergillosis (IPA). International guidelines provide different recommendations for a first-line antifungal therapy and, in most of them, echinocandins are considered the first-line treatment for IC, and triazoles are so for the treatment of IPA. However, liposomal amphotericin B (L-AmB) is still considered a second-line therapy for both clinical entities. Although in the last decade the management of IFI has improved, several controversies persist. The antifungal drugs currently available may have a suboptimal activity, or be wrongly used in certain IFI involving critically ill patients. The aim of this review is to analyze when to provide individualized antifungal therapy to critically ill patients suffering from IFI, emphasizing the role of L-AmB. Drug-drug interactions, the clinical status, infectious foci (peritoneal candidiasis is discussed), the fungal species involved, and the need of monitoring the concentration of the antifungal drug in the patient are considered.     

Mucormycosis: The hidden and forgotten disease

Mucormycosis is a rare but serious fungal infection caused by a group of moulds called mucormycetes. More attention has recently been paid to it due to its association with coronavirus disease 2019 (COVID-19). Thus, it is important to review the progress of studies on mucormycosis and highlight the important findings in relation to epidemiology, clinical manifestation, major risk factors, diagnostic strategies and management. An electronic literature search was performed in PubMed using the keywords: Rhizopus, Mucorales, mucormycosis, zygomycosis, zygomycetes, COVID-19, the drugs (azoles, posaconazole, isavuconazole, amphotericin B pharmaceutical preparations and caspofungin), combination therapy, diagnosis and clinical manifestations. Studies written in the English language from January 1960 to 2021 were considered for this review article. All search results were reviewed, and the relevance of each article was determined by the authors independently. The review emphasized the fact that the diagnosis of mucormycosis is difficult, it is necessary to have a high index of suspicion to identify it, surgical debridement should be done prior to the dissemination of infection to improve clinical outcomes and identifying underlying risk factors is important for proper treatment. Moreover, antifungal therapeutic options are few with polyenes and their combinations should be appropriate for empirical therapy while posaconazole and isavuconazole are best reserved for de-escalation, refractory cases or patients intolerant to amphotericin B.     

Treatment of breakthrough fungal infections: Is there one best drug strategy?

Widespread use of antifungal drugs in prophylactic and therapeutic settings is associated with breakthrough infections primarily due to Aspergillus and non-Aspergillus molds and non-albicans Candida. Reasons for breakthrough include worsening of initial infection, superinfection, and co-infection; subtherapeutic drug levels, emergence of antifungal resistance, and host factors may contribute to progression of the initial infection. Establishing an etiologic diagnosis is crucial because clinical and radiological features are nonspecific, and empirically chosen drug(s) may not provide appropriate antimicrobial coverage. Evidence-based data do not exist for the management of breakthrough infection. Current treatment strategies include switching therapy to a drug of another class, dose optimization, and combinations of drugs. Dosage adjustment of triazoles guided by serum concentrations may ensure optimal efficacy and avoidance of toxicity. A combination of an echinocandin plus a triazole or polyene appears to be synergistically effective against invasive aspergillosis. The treatment strategy needs to be individualized. For an optimal outcome, reversal of immunosuppression is essential.     

Current Diagnosis and Management of Mucormycoses

Due to the rising incidence of diabetes mellitus, the increasing populations of immunocompromised individuals of varied etiologies, and the progresses that have been made in the management of the critically ill, the incidence of invasive fungal infections, in particular those caused by the Mucorales, is increasing. Currently available diagnostics frequently miss this infection. Knowledge of the factors placing individuals at risk for and the varied clinical presentations of mucormycosis should alert clinicians of the possible presence of this infection. Survival of individuals with mucormycosis is dependant on prompt diagnosis and aggressive therapy with antifungal agents; surgical debridement; and, if possible, reversal of the risk factors predisposing the individual to this infection. It is hoped that improved diagnostic testing, improvements in pharmacotherapy, and adjunctive therapies will improve the morbidity and mortality of mucormycosis.     

El tratamiento de la mucormicosis (cigomicosis) en el siglo xxi

Infections due to zygomycetes, caused by mucorales and entomophthorales, are characterized by angioinvasion and invasion of neighboring organs or structures. Mucorales most commonly cause rhinocerebral, pulmonary, cutaneous or disseminated infection and its spread is favored by several diseases (such as diabetes or chronic kidney disease) and risk factors (neutropenia, immunosuppression, iron overload). They have a high mortality rate, and the key to success in their treatment are early diagnosis, prompt administration of antifungal treatment, and extensive surgical debridement. Currently, isavuconazole constitutes an option for the treatment of those mucormycosis refractory to liposomal amphotericin B. Due to its pharmacokinetic and pharmacodynamic characteristics and its low toxicity, it is also the best choice for maintenance therapy.     

A Mucormycosis Case in a Cirrhotic Patient Successfully Treated with Posaconazole and Review of Published Literature

Mucormycosis is an invasive fungal infection associated with a high mortality rate, especially in immunocompromised hosts. Mucormycosis rarely occurs in cirrhotic patients. Here, we report a case of mucormycosis with underlying liver cirrhosis and diabetes mellitus. The patient suffered from maxillary sinusitis and osteomyelitis, and the infection was successfully treated with antifungal agents, surgical debridement, and hyperbaric oxygen therapy. The antifungal treatments used were liposomal amphotericin B, itraconazole, and posaconazole. Although our patient had liver cirrhosis (Child-Pugh classification B), no hepatic decompensation was developed during the treatment course of posaconazole. This is the first report of the safe and effective use of posaconazole for the treatment of mucormycosis in a cirrhotic patient.     

Mucormicosis: perspectiva de manejo actual y de futuro

Infections caused by mucorales, with an increasing incidence after candidiasis and aspergillosis, are characterized by the fast angioinvasion of blood vessels and invasion of neighboring organs or structures. Mucorales most commonly cause rhinocerebral, pulmonary, cutaneous, digestive or disseminated infections, and their spread is favored by certain underlying diseases (diabetes, kidney failure) and risk factors (neutropenia, immunosuppression, iron overload). These infections have a high mortality rate, over 40% in many series, and the key to their cure depends on both an early diagnosis and an antifungal treatment, associated in most cases with extensive surgical debridement and other adjunctive therapies. Currently, there are international guidelines, not only local ones, for the management of mucormycosis, in which it is considered by consensus and with a strong recommendation that first-line treatment with high-dose liposomal amphotericin B is the best choice. The combined antifungal treatment of polyene agents with triazoles or candins remains in open debate.     

Invasive Fungal Infections in the Child with Chronic Granulomatous Disease

Invasive fungal infections (IFI) are a major threat for patients with chronic granulomatous disease (CGD) which is an inherited disorder of NADPH oxidase. The absence of a functional NADPH oxidase complex affects the display of an efficient antimicrobial effect as well as a controlled inflammatory response. Invasive aspergillosis caused by either Aspergillus fumigatus or A. nidulans is the most common IFI. Aspergillus nidulans infections seem to display a unique interaction with the CGD host and are seldom reported in other immunocompromised hosts. The occurrence of mucormycosis in the CGD host is mainly noted in the setting of treatment of inflammatory complications with immunosuppressive drugs. Candida infections are infrequently seen and show an age-dependent clinical presentation mainly affecting infants and young children. Furthermore, the child with CGD is susceptible to a wide range of fungal pathogens, indicating the need to determine the causative fungus, often by invasive diagnostic approaches, to guide optimal and rational treatment. Currently, it is becoming more and more clear that the exaggerated inflammatory response to fungal infection in the CGD host is leading in the pathogenesis, and antiinflammatory treatment might become as important as antifungal treatment in this specific host.     

Siderophore Production by Pathogenic Mucorales and Uptake of Deferoxamine B

Clinical reports have established that mucormycosis, mainly caused by Rhizopus spp., frequently occurs in patients treated with deferoxamine B (DFO, Desferal^®) which is misappropriated by these fungi. Siderophore production by twenty mucoralean isolates was therefore investigated using a commercial iron-depleted culture medium. Siderophore production was detected for most of the isolates. Our experiments confirmed that feroxamine B (iron chelate of DFO) promoted in vitro growth of Rhizopus arrhizus. Electrophoretic analysis of somatic extracts revealed iron-regulated proteins of 60 and 32 kDa which were lacking in iron-depleted culture conditions. Using a fluorescent derivative of deferoxamine B, we showed by fluorescence microscopy the entry of the siderophore within the fungal cells, thus suggesting a shuttle mechanism encompassing the uptake of the entire siderophore-ion complex into the cell. This useful tool renders possible a better understanding of iron metabolism in Mucorales which could lead to the development of new diagnostic method or new antifungal therapy using siderophores as imaging contrast agents or active drug vectors.     

Hyperthyroidism Secondary to Disseminated Mucormycosis in a Child with Acute Lymphoblastic Leukemia: Case Report and a Review of Published Reports

Thyroiditis due to fungal infection is an extremely rare cause of hyperthyroidism. The most common etiological factor of thyroiditis is Aspergillus. Infections due to members of the Mucorales have been an increasing clinical problem in recent years, and the prognosis in generalized infections due to those fungi is usually very poor. No hyperthyroidism in a child with thyroiditis due to mucormycosis has been reported in the literature so far. We describe a clinical course of generalized mucormycosis with thyroid involvement in a 12-year-old girl treated for acute lymphoblastic leukemia. The child underwent a hyperthyroidism connected with thyroid involvement due to a fungal process. The diagnosis was based on the clinical signs, laboratory findings and typical ultrasound scan; however, later attempt to amplify the fungi DNA from the tissue block has failed. The child died because of multiorgan failure due to general fungal infection 49 days after the invasive fungal infection was diagnosed. The generalized mucormycosis is always connected with poor prognosis and the mortality is high.     

Treatment of Invasive Candida Infections in the Neonatal Intensive Care Unit

Invasive Candida infections are a leading cause of morbidity and mortality in the neonatal intensive care unit (NICU). Extremely preterm and very low birth weight infants are at the highest risk of infection. There are currently no antifungal agents that have FDA-labeling for the treatment of invasive candidiasis in the neonatal population. Based on the current IDSA guidelines, amphotericin and fluconazole are considered first-line options for neonatal candidiasis. The newer antifungal agents (i.e., echinocandins and voriconazole) are currently considered second-line or salvage therapy; however, evidence supporting their use is emerging. This review focuses on the supporting evidence for the selection of antifungal agents for treatment of invasive Candida infections in the NICU.     

The role of adjuvant agents in treating fungal diseases

Invasive fungal infections (IFIs) remain a significant cause of morbidity and mortality despite the recent introduction of new antifungal medications. In this review, the available data on the use of adjuvant agents for the treatment of IFIs are discussed. Cytokines such as interferon-γ, colony-stimulating factors, granulocyte transfusions, and the monoclonal antibody efungumab may have in a role in the management of IFIs through augmentation of the host immune response, whereas pathogen-specific vaccines may help prevent infection. Pentraxin 3, an acute phase protein, may assist in the prevention and treatment of aspergillosis. Deferasirox, an iron chelator, is being investigated as an adjunctive therapy for the treatment of zygomycosis. Lactoferrin, an ironbinding protein, appears to have activity in Candida and Aspergillus infections, and omiganan may help prevent fungal catheter-related infections. Although none of these agents are currently approved for the treatment of IFIs, they may be involved in current and/or future treatment options when used in combination with antifungal drugs.     

Fob1 and Fob2 Proteins Are Virulence Determinants of Rhizopus oryzae via Facilitating Iron Uptake from Ferrioxamine

Dialysis patients with chronic renal failure receiving deferoxamine for treating iron overload are uniquely predisposed for mucormycosis, which is most often caused by Rhizopus oryzae. Although the deferoxamine siderophore is not secreted by Mucorales, previous studies established that Rhizopus species utilize iron from ferrioxamine (iron-rich form of deferoxamine). Here we determined that the CBS domain proteins of Fob1 and Fob2 act as receptors on the cell surface of R. oryzae during iron uptake from ferrioxamine. Fob1 and Fob2 cell surface expression was induced in the presence of ferrioxamine and bound radiolabeled ferrioxamine. A R. oryzae strain with targeted reduced Fob1/Fob2 expression was impaired for iron uptake, germinating, and growing on medium with ferrioxamine as the sole source of iron. This strain also exhibited reduced virulence in a deferoxamine-treated, but not the diabetic ketoacidotic (DKA), mouse model of mucormycosis. The mechanism by which R. oryzae obtains iron from ferrioxamine involves the reductase/permease uptake system since the growth on ferrioxamine supplemented medium is associated with elevated reductase activity and the use of the ferrous chelator bathophenanthroline disulfonate abrogates iron uptake and growth on medium supplemented with ferrioxamine as a sole source of iron. Finally, R. oryzae mutants with reduced copies of the high affinity iron permease (FTR1) or with decreased FTR1 expression had an impaired iron uptake from ferrioxamine in vitro and reduced virulence in the deferoxamine-treated mouse model of mucormycosis. These two receptors appear to be conserved in Mucorales, and can be the subject of future novel therapy to maintain the use of deferoxamine for treating iron-overload.     

Successful posaconazole salvage therapy for rhinocerebral mucormycosis in a child with leukemia. Review of the literature

BackgroundMucormycosis is a fungal infection caused by species of the Mucorales order. These microorganisms are angioinvasive, with rapid disease progression and potentially lethal in its rhinocerebral form.Case reportWe present the case of a 12-year-old female with trisomy 21, acute lymphoblastic leukemia and diabetes, with fever and neutropenia who developed rhinocerebral mucormicosis. After treatment with amphotericin B lipid complex and extensive surgery, disease progressed and posaconazole was added as salvage treatment with full remission of the infection. Four years after diagnosis the patient continues without relapse of mucormycosis or leukemia.ConclusionsThis case highlights the use of posaconazole as either monotherapy or combined therapy. Although it is still debated, it can be considered an option for salvage treatment in children with non-responding mucormycosis, despite lack of standard dosage in pediatric patients.     

Novel dual-function CellDetect® staining technology: wedding morphology and tinctorial discrimination to detect cervical neoplasia

Immunocompromised patients who develop invasive filamentous mycotic infections can be efficiently treated if rapid identification of the causative fungus is obtained. We report a case of fatal necrotic pneumonia caused by combined pulmonary invasive mucormycosis and aspergillosis in a 66 year-old renal transplant recipient. Aspergillus was first identified during the course of the disease by cytological examination and culture (A. fumigatus) of bronchoalveolar fluid. Hyphae of Mucorales (Rhizopus microsporus) were subsequently identified by culture of a tissue specimen taken from the left inferior pulmonary lobe, which was surgically resected two days before the patient died. Histological analysis of the lung parenchyma showed the association of two different filamentous mycoses for which the morphological features were evocative of aspergillosis and mucormycosis. However, the definitive identification of the associative infection was made by polymerase chain reaction (PCR) performed on deparaffinized tissue sections using specific primers for aspergillosis and mucormycosis. This case demonstrates that discrepancies between histological, cytological and mycological analyses can occur in cases of combined mycotic infection. In this regard, it shows that PCR on selected paraffin blocks is a very powerful method for making or confirming the association of different filamentous mycoses and that this method should be made available to pathology laboratories.     

Immunomodulation Therapy for Invasive Aspergillosis: Discussion on Myeloid Growth Factors,Recombinant Cytokines,and Antifungal Drug Immune Modulation

Understanding fungal pathogenesis and host-pathogen immune interaction at various stages of infection is critical to examine strategies for bolstering antifungal immune defenses. Recombinant myeloid growth factors, especially granulocyte-macrophage colony-stimulating factor and the protagonist T helper (Th) 1 cytokine, interferon-γ, are most frequently used in patients with refractory invasive aspergillosis. These cytokines are given alone or in combination and have also been used together in neutropenic patients receiving donor granulocyte transfusions. Recently, a number of investigators have presented provoking data regarding auxiliary effect of conventional antifungal drugs on hosts’ immune response and pathogen’s susceptibility for antifungal immune defenses. Antifungal immunotherapy and its ameliorative role in treatment for Aspergillus disease will need clinical trials that 1) consider well-characterized fungal disease; 2) illustrate underlying immune defect(s) (such as Th1 vs Th2, vs Th17 and functional status of natural killer and effector scavenger cells); 3) include a more specific patient population; 4) include standardized antifungal drug therapy; and importantly 5) consider its impact on hosts’ immune response and changes in pathogen’s susceptibility and virulence. At present, immunotherapy is reserved for patients with life-threatening invasive fungal disease in whom conventional antifungal drug therapy has failed, or for patients with advanced fungal disease and with factors associated with high probability of failure of conventional therapy alone.     

Successful Treatment of Pulmonary Mucormycosis Caused by <Emphasis Type="Italic">Cunninghamella bertholletiae</Emphasis> with High-Dose Liposomal Amphotericin B (10 mg/kg/day) Followed by a Lobectomy in Cord Blood Transplant Recipients

Infection caused by Cunninghamella bertholletiae carries one of the highest mortality rates among mucormycosis, and there are no reported cases that survived from the infection in allogeneic hematopoietic stem cell transplantation recipients occurring before neutrophil engraftment. Here, we present two cases of pulmonary mucormycosis caused by C. bertholletiae occurring before neutrophil engraftment after cord blood transplantation. Both were successfully treated with high-dose liposomal amphotericin B (10 mg/kg/day) combined with micafungin, which was then followed by neutrophil recovery, reduction in immunosuppressive agents, and a subsequent lobectomy. The intensive antifungal therapy immediately administered upon suspicion of mucormycosis greatly suppressed the infection in its early stage and was well tolerated despite its prolonged administration and simultaneous use of nephrotoxic agents after transplantation. Although the synergic effect of micafungin remains unclear, these cases highlight the importance of prompt administration of high-dose lipid polyene when suspecting mucormycosis in highly immunocompromised patients, which enables subsequent diagnostic and therapeutic interventions, resulting in a favorable outcome.