Immunologic mechanisms of fingolimod and the role of immunosenescence in the risk of cryptococcal infection: A case report and review of literature

Presentation and Outcome in S1P-RM and Natalizumab-Associated Progressive Multifocal Leukoencephalopathy: A Multicenter Cohort Study

BACKGROUND AND OBJECTIVES

Progressive multifocal leukoencephalopathy (PML) is a severe neurologic disease resulting from JC virus reactivation in immunocompromised patients. Certain multiple sclerosis (MS) disease-modifying therapies (DMTs) are associated with PML risk, such as natalizumab and, more rarely, sphingosine-1-phosphate receptor modulators (S1P-RMs). Although natalizumab-associated PML is well documented, information on S1P-RM-associated PML is limited. The aim of this study is to compare clinical presentations and outcomes between the 2 groups.

METHODS

A retrospective multicenter cohort study included patients with PML from 2009 to 2022 treated with S1P-RMs or natalizumab. Data on clinical and radiologic presentation, outcomes, immune reconstitution inflammatory syndrome (IRIS), survival, disability (using the modified Ranking scale-mRS), and MS relapses post-PML were analyzed.

RESULTS

Of 88 patients, 84 were analyzed (20 S1P-RM, 64 natalizumab). S1P-RM-associated PML was diagnosed in older patients (median age 52 vs 44 years, p < 0.001) and after longer treatment duration (median 63.9 vs 40 months, p < 0.001). Similarly, S1P-RM patients were more prone to show symptoms at diagnosis (100 vs 80.6%, p = 0.035), had more disseminated lesions (80% vs 34.9%, p = 0.002), and had higher gadolinium enhancement (65% vs 39.1%, p = 0.042). Natalizumab patients had a higher IRIS development rate (OR: 8.3 [1.92-33.3]). Overall, the outcome (mRS) at 12 months was similar in the 2 groups (OR: 0.81 [0.32-2.0]). Yet, post-treatment MS activity was higher in S1P-RM cases (OR: 5.7 [1.4-22.2]).

DISCUSSION

S1P-RM-associated PML shows reduced IRIS risk but higher post-treatment MS activity. Clinicians should tailor post-PML treatment based on pre-PML medication.

The emerging links between immunosenescence in innate immune system and neurocryptococcosis

Immunosenescence refers to the age-related progressive decline of immune function contributing to the increased susceptibility to infectious diseases in older people. Neurocryptococcosis, an infectious disease of central nervous system (CNS) caused by Cryptococcus neoformans (C. Neoformans) and C. gattii, has been observed with increased frequency in aged people, as result of the reactivation of a latent infection or community acquisition. These opportunistic microorganisms belonging to kingdom of fungi are capable of surviving and replicating within macrophages. Typically, cryptococcus is expelled by vomocytosis, a non-lytic expulsive mechanism also promoted by interferon (IFN)-I, or by cell lysis. However, whereas in a first phase cryptococcal vomocytosis leads to a latent asymptomatic infection confined to the lung, an enhancement in vomocytosis, promoted by IFN-I overproduction, can be deleterious, leading the fungus to reach the blood stream and invade the CNS. Cryptococcus may not be easy to diagnose in older individuals and, if not timely treated, could be potentially lethal. Therefore, this review aims to elucidate the putative causes of the increased incidence of cryptococcal CNS infection in older people discussing in depth the mechanisms of immunosenscence potentially able to predispose to neurocryptococcosis, laying the foundations for future research. A deepest understanding of this relationship could provide new ways to improve the prevention and recognition of neurocryptococcosis in aged frail people, in order to quickly manage pharmacological interventions and to adopt further preventive measures able to reduce the main risk factors.

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.

The pathobiology of human fungal infections

Human fungal infections are a historically neglected area of disease research, yet they cause more than 1.5 million deaths every year. Our understanding of the pathophysiology of these infections has increased considerably over the past decade, through major insights into both the host and pathogen factors that contribute to the phenotype and severity of these diseases. Recent studies are revealing multiple mechanisms by which fungi modify and manipulate the host, escape immune surveillance and generate complex comorbidities. Although the emergence of fungal strains that are less susceptible to antifungal drugs or that rapidly evolve drug resistance is posing new threats, greater understanding of immune mechanisms and host susceptibility factors is beginning to offer novel immunotherapeutic options for the future. In this Review, we provide a broad and comprehensive overview of the pathobiology of human fungal infections, focusing specifically on pathogens that can cause invasive life-threatening infections, highlighting recent discoveries from the pathogen, host and clinical perspectives. We conclude by discussing key future challenges including antifungal drug resistance, the emergence of new pathogens and new developments in modern medicine that are promoting susceptibility to infection.

Seroprevalence of Toxoplasma gondii and Borrelia burgdorferi infections in patients with multiple sclerosis in Poland

Multiple sclerosis (MS) is a chronic, demyelinating disease of the central nervous system that affects mainly young people. It is believed that the autoimmune process observed in the pathogenesis of MS is influenced by a complex interaction between genetic and environmental factors, including infectious agents. The results of this study suggest the protective role of Toxoplasma gondii infections in MS. Interestingly, high Toxoplasma IgM seropositivity in MS patients receiving immunomodulatory drugs (IMDs) was identified. On the other hand, Borrelia infections seem to be positively associated with MS. Although the interpretation of our results is limited by the retrospective nature of the studies, the results strongly indicate that further experimental and clinical studies are needed to explain the role of infectious agents in the development and pathophysiological mechanisms of MS.

Managing multiple sclerosis in individuals aged 55 and above: a comprehensive review

Multiple Sclerosis (MS) management in individuals aged 55 and above presents unique challenges due to the complex interaction between aging, comorbidities, immunosenescence, and MS pathophysiology. This comprehensive review explores the evolving landscape of MS in older adults, including the increased incidence and prevalence of MS in this age group, the shift in disease phenotypes from relapsing-remitting to progressive forms, and the presence of multimorbidity and polypharmacy. We aim to provide an updated review of the available evidence of disease-modifying treatments (DMTs) in older patients, including the efficacy and safety of existing therapies, emerging treatments such as Bruton tyrosine kinase (BTKs) inhibitors and those targeting remyelination and neuroprotection, and the critical decisions surrounding the initiation, de-escalation, and discontinuation of DMTs. Non-pharmacologic approaches, including physical therapy, neuromodulation therapies, cognitive rehabilitation, and psychotherapy, are also examined for their role in holistic care. The importance of MS Care Units and advance care planning are explored as a cornerstone in providing patient-centric care, ensuring alignment with patient preferences in the disease trajectory. Finally, the review emphasizes the need for personalized management and continuous monitoring of MS patients, alongside advocating for inclusive study designs in clinical research to improve the management of this growing patient demographic.

Teaching NeuroImage: Cryptococcus in a Woman With Multiple Sclerosis on Fingolimod

A 33-year-old woman with relapsing remitting multiple sclerosis who was on fingolimod for 5 years presented with a solitary skin lesion on her abdomen (Figure 1) for 2 months, which was unresponsive to antibiotics. The neurologic examination was normal. She denied having infectious symptoms, chest pain, shortness of breath, recent travel, trauma to the area, or animal exposure. Her most recent absolute lymphocyte count was 0.22 × 109/L (reference 1.2-4.0 109/L). The differential diagnosis included skinfold friction, dermatofibroma, pyoderma gangrenosum, and basal cell carcinoma. Although a dermatologist did not initially recommend a biopsy because the lesion was not ulcerated, she obtained one based on the recommendation of her neurologist. Shave biopsy revealed cryptococcal fungal infection (Figure 2). There was no evidence of asymptomatic disseminated cryptococcus. The proposed mechanism for the lesion involves a latent infection while immunocompetent with reactivation once immunocompromised.1 Cryptococcus infections are associated with immunosuppression, most often due to human immunodeficiency virus infection, and only 6 fingolimod-associated cutaneous infections have been reported in the literature.2 Patients with MS on immunosuppressant medication should be carefully screened for cutaneous infections.

Cryptococcal meningoencephalitis in multiple sclerosis treated with fingolimod

A 21-year-old woman with multiple sclerosis (taking regular fingolimod) developed sudden-onset severe headache with nausea and malaise. Neurological examination was normal and she was afebrile. Blood results showed lymphocytes 0.53 x 109/L and C reactive protein 19 mg/L. CT scan of head and venogram were normal. CSF showed an opening pressure of 33 cm H2O and an incidental light growth of Cryptococcus neoformans, confirmed with positive India Ink stain and a positive cryptococcal antigen (1:100). She was treated for cryptococcal meningoencephalitis with amphotericin and flucytosine. Her presenting symptoms had closely mimicked subarachnoid haemorrhage. This atypical presentation of cryptococcal CNS infection highlights the need for vigilance in immunosuppressed patients.

Latin American consensus recommendations on the risk of infections in people with multiple sclerosis treated with disease modifying drugs

INTRODUCTION

The emergence of several therapeutic options in multiple sclerosis (MS), which significantly modify the immune system functioning, has led to the need for the consideration of additional factors, such as risk of infections, in the decision-making process. The aim of these consensus recommendations was to discuss and perform a practical guide to Latin American neurologists on the risk of infections at diagnosis, follow-up and prior to initiation of DMDs.

METHODS

A panel of Latin American neurologists, experts in demyelinating diseases and dedicated to management and care of MS patients, gathered during 2021 and 2022 to make consensus recommendations on the risk of infections in PwMS treated with DMDs in Latin America. The RAND/UCLA methodology was developed to synthesize the scientific evidence and expert opinions on health care topics and was used for reaching a formal agreement.

RESULTS

Recommendations were established based on relevant published evidence and expert opinion, focusing on: 1- baseline infection disease and vaccination status; 2- opportunistic infections; 3- progressive multifocal leukoencephalopathy; 4- genitourinary system infections; 5- respiratory tract infections; 6- digestive system infections, 7-others local infections and 8- COVID-19.

CONCLUSION

The recommendations of this consensus seek to optimize the care, management and treatment of PwMS in Latin America. The standardized evidence-based care of pwMS infections will allow better outcomes.

Cutaneous presentation of cryptococcal infection with subclinical central nervous system involvement secondary to fingolimod therapy

Fingolimod is a multiple sclerosis disease-modifying therapy which sequestrates lymphocytes in the lymph nodes, thereby reducing peripheral blood lymphocytes. Cryptococcal infection is an important adverse effect which should be recognised. We report a case of cutaneous and central nervous system infection who presented with isolated cutaneous symptoms in the absence of neurological or systemic manifestations.

Outcomes and Health Care Service Use in Adults 50 Years or Older With and Without Multiple Sclerosis: A 6-Year Observational Analysis

BACKGROUND

Multiple sclerosis (MS) typically presents in young adulthood. Recent data show the highest prevalence of MS in people aged 55 to 64 years; however, there are limited studies of this population.

METHODS

Administrative US claims data from IBM-Truven MarketScan commercial and Medicare databases (2011-2017) were analyzed. People with MS 50 years or older were assigned to the aging MS cohort (n = 10,746). The matched controls were people 50 years or older without MS (n = 10,746). Multivariable models compared outcomes between groups.

RESULTS

Infections were more frequent in the aging MS cohort vs matched controls (61% vs 45%; P < .0001); urinary tract, acute upper respiratory tract, and herpes zoster were the most frequent infection types. Malignancy rates were 20% for both groups (P = .8167); skin, breast, and prostate malignancies were the most frequent types. Skilled nursing facilities (aging MS cohort, 12%; matched controls, 3%; P < .0001) and MRI (aging MS cohort, 87%; matched controls, 37%; P < .0001) were used more frequently in the aging MS cohort; brain and spine were the most frequent types of MRI in the aging MS cohort. Time to first cane/walker or wheelchair use was shorter in the aging MS cohort (cane/walker use: HR, 2.1; 95% CI, 1.9-2.3; P < .0001; wheelchair use: HR, 6.9; 95% CI, 6.0-8.1; P < .0001).

CONCLUSIONS

In people 50 years or older, measures typically associated with worse health primarily resulted from having MS rather than being a consequence of aging alone.

Current status and new developments in sphingosine-1-phosphate receptor antagonism: fingolimod and more

INTRODUCTION

Fingolimod was the first oral disease-modifying treatment approved for relapsing-remitting multiple sclerosis (MS) that serves as a sphingosine-1-phosphate receptor (S1PR) agonist. The efficacy is primarily mediated by S1PR subtype 1 activation, leading to agonist-induced down-modulation of receptor expression and further functional antagonism, blocking the egression of auto-aggressive lymphocytes from the lymph nodes in the peripheral compartment. The role of S1P signaling in the regulation of other pathways in human organisms through different S1PR subtypes has received much attention due to its immune-modulatory function and its significance for the regeneration of the central nervous system (CNS). The more selective second-generation S1PR modulators have improved safety and tolerability profiles.

AREAS COVERED

This review has been carried out based on current data on S1PR modulators, emphasizing the benefits of recent advances in this emergent class of immunomodulatory treatment for MS.

EXPERT OPINION

Ongoing clinical research suggests that S1PR modulators represent an alternative to first-line therapies in selected cases of MS. A better understanding of the relevance of selective S1PR pathways and the ambition to optimize selective modulation has improved the safety and tolerability of S1PR modulators in MS therapy and opened new perspectives for the treatment of other diseases.

Cryptococcal chest wall mass and rib osteomyelitis associated with the use of fingolimod: A case report and literature review

Being introduced in 2010, fingolimod was among the first oral therapies for relapsing multiple sclerosis (MS). Since that time, postmarketing surveillance has noted several case reports of various cryptococcal infections associated with fingolimod use. To date, approximately 15 such case reports have been published. We present the first and unique case of cryptococcal chest wall mass and rib osteomyelitis associated with fingolimod use. The patient presented with left-side chest pain and was found to have a lower left chest wall mass. Computerized tomography (CT) showed chest wall mass with the destruction of left 7th rib. Aspirate from the mass grew Cryptococcus neoformans. The isolate was serotype A. Fingolimod was stopped. The patient received liposomal amphotericin B for 2 weeks and started on fluconazole with a plan to continue for 6–12 months. The follow-up CT in 6 weeks showed a marked decrease in the size of the chest wall mass. In conclusion, our case highlights the atypical and aggressive form of cryptococcal infection possibly related to immunosuppression from fingolimod use.

Multiple sclerosis and the risk of infection: Association of British Neurologists consensus guideline

Infection in people with multiple sclerosis (MS) is of major concern, particularly for those receiving disease-modifying therapies. This article explores the risk of infection in people with MS and provides guidance-developed by Delphi consensus by specialists involved in their management-on how to screen for, prevent and manage infection in this population.

A Case of Fingolimod-associated Cryptococcal Meningitis

BACKGROUND

Leukopenia, a rare adverse effect of Fingolimod therapy, paves the way for opportunistic infections. In this study, we reported rare fingolimod associated cryptococcal meningitis.

CASE PRESENTATION

A 39-year-old woman with RRMS was referred to the emergency department. The patient's major complaints were headache, fever, weakness, and progressive loss of consciousness within the last two days prior to the referral. The patient had a history of hospitalization due to RRMS [two times]. In the second hospitalization, interferon Beta-1a was replaced with Fingolimod. Using polymerase chain reaction, Cryptococcus neoformans was detected in CSF. Liposomal amphotericin B and fluconazole [800 mg per day] were started. Six weeks later, the patient was discharged without any major complaints.

CONCLUSION

Albeit fingolimod associated cryptococcal meningitis is a rare event, Fingolimod therapy in patients with MS should be performed cautiously. Regular follow-ups may give rise to a timely diagnosis of probable fingolimod associated cryptococcal meningitis. Fingolimod therapy can lead to lymphocytopenia and various infections. We, therefore, suggest that intermittent blood lymphocyte counts as well as monitoring of clinical manifestations among MS patients treated with Fingolimod to avoid additional neurological and physical disabilities in these patients.

An Immunogenic and Slow-Growing Cryptococcal Strain Induces a Chronic Granulomatous Infection in Murine Lungs

Many successful pathogens cause latent infections, remaining dormant within the host for years but retaining the ability to reactivate to cause symptomatic disease. The human opportunistic fungal pathogen Cryptococcus neoformans establishes latent pulmonary infections in immunocompetent individuals upon inhalation from the environment. These latent infections are frequently characterized by granulomas, or foci of chronic inflammation, that contain dormant and persistent cryptococcal cells. Immunosuppression can cause these granulomas to break down and release fungal cells that proliferate, disseminate, and eventually cause lethal cryptococcosis. This course of fungal latency and reactivation is understudied due to limited models, as chronic pulmonary granulomas do not typically form in mouse cryptococcal infections. A loss-of-function mutation in the Cryptococcus-specific MAR1 gene was previously described to alter cell surface remodeling in response to host signals. Here, we demonstrate that the mar1Δ mutant strain persists long term in a murine inhalation model of cryptococcosis, inducing a chronic pulmonary granulomatous response. We find that murine infections with the mar1Δ mutant strain are characterized by reduced fungal burden, likely due to the low growth rate of the mar1Δ mutant strain at physiological temperature, and an altered host immune response, likely due to inability of the mar1Δ mutant strain to properly employ virulence factors. We propose that this combination of features in the mar1Δ mutant strain collectively promotes the induction of a more chronic inflammatory response and enables long-term fungal persistence within these granulomatous regions.

Three Models of Vaccination Strategies Against Cryptococcosis in Immunocompromised Hosts Using Heat-Killed Cryptococcus neoformans Δsgl1

Vaccines are one of the greatest medical accomplishments to date, yet no fungal vaccines are currently available in humans mainly because opportunistic mycoses generally occur during immunodeficiencies necessary for vaccine protection. In previous studies, a live, attenuated Cryptococcus neoformans Δsgl1 mutant accumulating sterylglucosides was found to be avirulent and protected mice from a subsequent lethal infection even in absence of CD4⁺ T cells, a condition most associated with cryptococcosis (e.g., HIV). Here, we tested three strategies of vaccination against cryptococcosis. First, in our preventative model, protection was achieved even after a 3-fold increase of the vaccination window. Second, because live C. neoformans Δsgl1-vaccinated mice challenged more than once with WT strain had a significant decrease in lung fungal burden, we tested C. neoformans Δsgl1 as an immunotherapeutic. We found that therapeutic administrations of HK C. neoformans Δsgl1 post WT challenge significantly improves the lung fungal burden. Similarly, therapeutic administration of HK C. neoformans Δsgl1 post WT challenge resulted in 100% or 70% survival depending on the time of vaccine administration, suggesting that HK Δsgl1 is a robust immunotherapeutic option. Third, we investigated a novel model of vaccination in preventing reactivation from lung granuloma using C. neoformans Δgcs1. Remarkably, we show that administration of HK Δsgl1 prevents mice from reactivating Δgcs1 upon inducing immunosuppression with corticosteroids or by depleting CD4⁺ T cells. Our results suggest that HK Δsgl1 represents a clinically relevant, efficacious vaccine that confers robust host protection in three models of vaccination against cryptococcosis even during CD4-deficiency.

Cryptococcal Meningitis Reported With Fingolimod Treatment: Case Series

BACKGROUND AND OBJECTIVES

To describe the characteristics of patients with MS reporting cryptococcal meningitis (CM) while treated with fingolimod.

METHODS

The Novartis safety database was searched for cases with CM between January 26, 2006, and February 28, 2020. The reporting rate of CM was estimated based on the case reports received and exposure to fingolimod in the postmarketing setting during the relevant period.

RESULTS

A total of 60 case reports of CM were identified, mostly from the United States. The median age was 48 years, and 51.8% were women. Most of the patients had recovered or were recovering at the time of final report. A fatal outcome occurred in 13 cases. During the study period, the rate of CM in patients with MS receiving fingolimod was estimated to be 8 per 100,000 patient-years (95% CI: 6.0; 10.0). The incidence of CM seemed to increase with duration of treatment; however, this relationship remains uncertain due to wide CIs and missing data.

DISCUSSION

The causal relationship between fingolimod treatment and CM is not yet fully understood. The CM mortality rate in fingolimod-treated patients is similar to that reported in HIV-negative patients. Vigilance for signs and symptoms of CM in patients receiving fingolimod, particularly the new onset of headaches and altered mental status, is essential. Early diagnosis and treatment are critical to reducing CM-associated mortality.

Molecular Mechanisms of Immunosenescene and Inflammaging: Relevance to the Immunopathogenesis and Treatment of Multiple Sclerosis

Aging is characterized, amongst other features, by a complex process of cellular senescence involving both innate and adaptive immunity, called immunosenescence and associated to inflammaging, a low-grade chronic inflammation. Both processes fuel each other and partially explain increasing incidence of cancers, infections, age-related autoimmunity, and vascular disease as well as a reduced response to vaccination. Multiple sclerosis (MS) is a lifelong disease, for which considerable progress in disease-modifying therapies (DMTs) and management has improved long-term survival. However, disability progression, increasing with age and disease duration, remains. Neurologists are now involved in caring for elderly MS patients, with increasing comorbidities. Aging of the immune system therefore has relevant implications for MS pathogenesis, response to DMTs and the risks mediated by these treatments. We propose to review current evidence regarding markers and molecular mechanisms of immunosenescence and their relevance to understanding MS pathogenesis. We will focus on age-related changes in the innate and adaptive immune system in MS and other auto-immune diseases, such as systemic lupus erythematosus and rheumatoid arthritis. The consequences of these immune changes on MS pathology, in interaction with the intrinsic aging process of central nervous system resident cells will be discussed. Finally, the impact of immunosenescence on disease evolution and on the safety and efficacy of current DMTs will be presented.

Evolution of Disease Modifying Therapy Benefits and Risks: An Argument for De-escalation as a Treatment Paradigm for Patients With Multiple Sclerosis

Background

Strategies for sequencing disease modifying therapies (DMTs) in multiple sclerosis (MS) patients include escalation, high efficacy early, induction, and de-escalation.

Objective

To provide a perspective on de-escalation, which aims to match the ratio of DMT benefit/risk in aging patients.

Methods

We reanalyzed data from a retrospective, real-world cohort of MS patients to model disease activity for oral (dimethyl fumarate and fingolimod) and higher efficacy infusible (natalizumab and rituximab) DMTs by age. For patients with relapsing MS, we conducted a controlled, stratified analysis examining odds of disease activity for oral vs. infusible DMTs in patients &lt;45 or ≥45 years. We reviewed the literature to identify DMT risks and predictors of safe discontinuation.

Results

Younger patients had lower probability of disease activity on infusible vs. oral DMTs. There was no statistical difference after age 54.2 years. When dichotomized, patients &lt;45 years on oral DMTs had greater odds of disease activity compared to patients on infusible DMTs, while among those ≥45 years, there was no difference. Literature review noted that adverse events increase with aging, notably infections in patients with higher disability and longer DMT duration. Additionally, we identified factors predictive of disease reactivation including age, clinical stability, and MRI activity.

Conclusion

In a real-world cohort of relapsing MS patients, high efficacy DMTs had less benefit with aging but were associated with increased risks. This cohort helps overcome some limitations of trials where older patients were excluded. To better balance benefits/risks, we propose a DMT de-escalation approach for aging MS patients.

The effects of dimethyl fumarate and fingolimod on T-cell lymphocyte proliferation in patients with multiple sclerosis

OBJECTIVE

The disease-modifying therapies (DMT), dimethyl fumarate (DMF) and fingolimod (FTY) improve the outcomes in multiple sclerosis (MS) by reducing relapses and numbers and volume of lesions. They mediate their effects through reduction of immune reactivation, which may potentially lead to lymphopaenia and increased risk of infections. Previous studies have examined the effects of these therapies on lymphocyte subsets; however, the in vivo effects on circulating lymphocyte proliferation require further elucidation. The aim of this study was to determine the effects of DMF and FTY on T-cell proliferation in patients with MS.

METHOD

We examined T-cell lymphocyte proliferation and lymphocyte subsets in ten patients (five on DMF, five on FTY) before starting DMT and again 4 to 11 months after being maintained on DMT.

RESULTS

In the FTY-treated group, the mean percentage proliferation was significantly lower using both assays (PHA assay mean percentage change - 51.2 ± 25.97, p < 0.05; anti-CD3/CD28 assay mean percentage change - 39.74 ± 27.85, p < 0.05). There was no statistical difference in T-cell lymphocyte proliferation in the DMF-treated group for either assay (PHA, p = 0.316; anti-CD3/CD28, p = 0.373).

CONCLUSIONS

This pilot study suggests that the T-lymphocytes of patients on FTY have an abnormal proliferation response as well as being reduced in the circulation.

Vaccine protection by Cryptococcus neoformans Δsgl1 is mediated by γδ T cells via TLR2 signaling

We previously reported that administration of Cryptococcus neoformans Δsgl1 mutant vaccine, accumulating sterylglucosides (SGs) and having normal capsule (GXM), protects mice from a subsequent infection even during CD4⁺ T cells deficiency, a condition commonly associated with cryptococcosis. Here, we studied the immune mechanism that confers host protection during CD4⁺T deficiency. Mice receiving Δsgl1 vaccine produce IFNγ and IL-17A during CD4⁺ T (or CD8⁺ T) deficiency, and protection was lost when either cytokine was neutralized. IFNγ and/or IL-17A are produced by γδ T cells, and mice lacking these cells are no longer protected. Interestingly, ex vivo γδ T cells are highly stimulated in producing IFNγ and/or IL-17A by Δsgl1 vaccine, but this production was significantly decreased when cells were incubated with C. neoformans Δcap59/Δsgl1 mutant, accumulating SGs but lacking GXM. GXM modulates toll-like receptors (TLRs), including TLR2. Importantly, neither Δsgl1 nor Δcap59/Δsgl1 stimulate IFNγ or IL-17A production by ex vivo γδ T cells from TLR2^-/- mice. Finally, TLR2^-/- animals do not produce IL-17A in response to Δsgl1 vaccine and were no longer protected from WT challenge. Our results suggest that SGs may act as adjuvants for GXM to stimulate γδ T cells in producing IFNγ and IL-17A via TLR2, a mechanism that is still preserved upon CD4⁺ T deficiency.

Four-year safety and effectiveness data from patients with multiple sclerosis treated with fingolimod: The Spanish GILENYA registry

Objective

To describe the profile of patients with multiple sclerosis (MS) treated with fingolimod in Spain and to assess the effectiveness and safety of fingolimod after 4 years of inclusion in the Spanish Gilenya Registry.

Methods

An observational, retrospective/prospective, multicenter case registry, including all patients with relapsing-remitting MS (RRMS) starting treatment with fingolimod in 43 centers in Spain. Analyses were performed in the overall population and in subgroups according to prior disease-modifying therapy (DMT): glatiramer acetate/interferon beta-1 (BRACE), natalizumab, other treatment, or naïve.

Results

Six hundred and sixty-six evaluable patients were included (91.1% previously treated with at least one DMT). The mean annualized relapse rate (ARR) prior to fingolimod was 1.12, and the mean EDSS at fingolimod initiation was 3.03. Fingolimod reduced the ARR by 71.4%, 75%, 75.5%, and 80.3%, after 1, 2, 3 and 4 years, respectively (p<0.001). This significant reduction in the ARR continued to be observed in all subgroups. After 4 years, the EDSS showed a minimal deterioration, with the EDSS scores from year 1 to year 4 remaining mostly stable. The percentage of patients without T1 Gd+ lesions progressively increased from 45.6% during the year prior to fingolimod initiation to 88.2% at year 4. The proportion of patients free from new/enlarged T2 lesions after 4 years of fingolimod treatment was 80.3%. This trend in both radiological measures was also observed in the subgroups. Adverse events (AEs) were experienced by up to 41.6% of patients (most commonly: lymphopenia [12.5%] and urinary tract infection [3.7%]). Most AEs were mild in severity, 3.6% of patients had serious AEs.

Conclusions

The patient profile was similar to other observational studies. The results obtained from the long-term use of fingolimod showed that it was effective, regardless of prior DMT, and it had adequate safety results, with a positive benefit-risk balance.

Cryptococcus neoformans Δsgl1 Vaccination Requires Either CD4+ or CD8+ T Cells for Complete Host Protection

Cryptococcus neoformans is a fungal pathogen causing life-threatening meningoencephalitis in susceptible individuals. Fungal vaccine development has been hampered by the fact that cryptococcosis occurs during immunodeficiency. We previously reported that a C. neoformans mutant (Δsgl1) accumulating sterylglucosides (SGs) is avirulent and provides complete protection to WT challenge, even under CD4+ T cell depletion, an immunodeficient condition commonly associated with cryptococcosis. We found high levels of SGs in the lungs post-immunization with Δsgl1 that decreased upon fungal clearance. Th1 cytokines increased whereas Th2 cytokines concurrently decreased, coinciding with a large recruitment of leukocytes to the lungs. Depletion of B or CD8+ T cells did not affect either Δsgl1 clearance or protection from WT challenge. Although CD4+ T cell depletion affected clearance, mice were still protected indicating that clearance of the mutant was not necessary for host protection. Protection was lost only when both CD4+ and CD8+ T cells were depleted, highlighting a previously unexplored role of fungal-derived SGs as an immunoadjuvant for host protection against cryptococcosis.

Primary Cutaneous Cryptococcosis in a Patient on Fingolimod: A Case Report

Primary cutaneous cryptococcosis is an uncommon condition. Patients with immunosuppression and those of older age are more susceptible to infection, warranting investigations into underlying systemic disease. We report the case of a 49-year-old male with multiple sclerosis in remission on fingolimod who presented with a non-healing skin lesion on his upper thigh for a duration of two years. Skin biopsy showed dermal parasitized histiocytes, and serum antigens for histoplasmosis and Cryptococcus were negative. Further investigation with polymerase chain reaction (PCR) demonstrated cutaneous cryptococcal infection, with no associated systemic signs or symptoms. This case report highlights an uncommon presentation of cutaneous cryptococcosis on an unexposed skin surface with successful and rapid improvement following fluconazole therapy without fingolimod discontinuation.

Applications of fluorine to the construction of bioisosteric elements for the purposes of novel drug discovery

Introduction There continues to be an exponential rise in the number of small molecule drugs that contain either a fluorine atom or a fluorinated fragment. While the unique properties of fluorine enable the precise modulation of a molecule's physicochemical properties, strategic bioisosteric replacement of fragments with fluorinated moieties represents an area of significant growth.Areas covered This review discusses the strategic employment of fluorine substitution in the design and development of bioisosteres in medicinal chemistry. In addition, the classic exploitation of trifluoroethylamine group as an amide bioisostere is discussed. In each of the case studies presented, emphasis is placed on the context-dependent influence of the fluorinated fragment on the overall properties/binding of the compound of interest.Expert opinion Whereas utilization of bioisosteric replacements to modify molecular structures is commonplace within drug discovery, the overarching lesson to be learned is that the chances of success with this strategy significantly increase as the knowledge of the structure/environment of the biological target grows. Coupled to this, breakthroughs and learnings achieved using bioisosteres within a specific program are context-based, and though may be helpful in guiding future intuition, will not necessarily be directly translated to future programs. Another important point is to bear in mind what implications a structural change based on a bioisosteric replacement will have on the candidate molecule. Finally, the development of new methods and reagents for the controlled regioselective introduction of fluorine and fluorinated moieties into biologically relevant compounds particularly in drug discovery remains a contemporary challenge in organic chemistry.

Risk of invasive fungal infections among patients treated with disease modifying treatments for multiple sclerosis: a comprehensive review

Introduction: Disease modifying treatments are commonly used in the treatment of multiple sclerosis. As different opportunistic infections have been reported, concerns are also raised regarding the risk of invasive fungal infections.Areas covered: Both clinical trials and observational studies on safety and efficacy of diseases modifying treatment for multiple sclerosis were reviewed and data regarding the occurrence of invasive fungal infections were reported. Papers evaluating the following drugs were reviewed: rituximab, ocrelizumab, alemtuzumab, fingolimod, natalizumab, dimethyl fumarate, interferon, glatiramer acetate, cladribine, teriflunomide.Expert opinion: Overall, the occurrence of invasive fungal infections was low, with most infective events reported among patients treated with monoclonal antibodies and fingolimod. Aspergillosis and cryptococcal meningitidis were the most representative fungal infections. Although not common, these infections may be difficult to diagnose and their fatality rate is often high. For this reason, screening protocols for fungal infections must be implemented in the clinical practice when managing patients with MS.

Incidence and Risk of Infection Associated With Fingolimod in Patients With Multiple Sclerosis: A Systematic Review and Meta-Analysis of 8,448 Patients From 12 Randomized Controlled Trials

Background and Aims: There is a controversy regarding whether fingolimod is associated with an increased risk of infection in patients with multiple sclerosis (MS). We performed a systematic review and meta-analysis of data from randomized controlled trials (RCTs) to determine the risk of infection in these patients.

Methods: We systematically searched PubMed, EMBASE, the Cochrane Library, and clinicaltrials.gov from inception to April 8, 2020, to identify RCTs that reported the occurrence of infection in patients with MS treated with fingolimod. Relative risks (RRs) and 95% confidence intervals (95% CIs) were calculated using the random-effects model.

Results: Twelve RCTs including 8,448 patients were eligible. Compared with the control (placebo and other active treatments), fingolimod significantly increased the risk of infection (RR, 1.16; 95% CI, 1.07–1.27; I², 81%), regardless of whether the infection was a general infection (RR, 1.14; 95% CI, 1.05–1.25; I², 78%), or a serious infection (RR, 1.49; 95% CI, 1.06–2.10; I², 0%). Analyses of subgroups found that fingolimod significantly increased the risk of lower respiratory infection (RR, 1.48; 95% CI, 1.19–1.85; I², 0%) and herpes virus infection (RR, 1.34; 95% CI, 1.01–1.78; I², 9%). There appears to be no dose-dependent increase in the risk of infection associated with fingolimod (0.5 mg: RR, 1.15; 95% CI, 1.07–1.25; I², 91%; 1.25 mg: RR, 1.11; 95% CI, 0.97–1.28; I², 81%; P_interaction = 0.66).

Conclusions: Compared with a placebo and other active treatments, fingolimod was associated with a 16% increase in the risk of infection, especially lower respiratory infection and herpes virus infection. The risk of infection associated with fingolimod might not be dose related.

The granuloma in cryptococcal disease

Although we have recognized cryptococcosis as a disease entity for well over 100 years, there are many details about its pathogenesis which remain unknown. A major barrier to better understanding is the very broad range of clinical and pathological forms cryptococcal infections can take. One such form has been historically called the cryptococcal granuloma, or the cryptococcoma. These words have been used to describe essentially any mass lesion associated with infection, due to their presumed similarity to the quintessential granuloma, the tubercle in tuberculosis. Although clear distinctions between tuberculosis and cryptococcal disease have been discovered, cellular and molecular studies still confirm some important parallels between these 2 diseases and what we now call granulomatous inflammation. In this review, we shall sketch out some of the history behind the term "granuloma" as it pertains to cryptococcal disease, explore our current understanding of the biology of granuloma formation, and try to place that understanding in the context of the myriad pathological presentations of this infection. Finally, we shall summarize the role of the granuloma in cryptococcal latency and present opportunities for future investigations.

FTY720 reactivates cryptococcal granulomas in mice through S1P receptor 3 on macrophages

FTY720 is a treatment for relapsing remitting multiple sclerosis (MS). It is an analog of sphingosine-1-phosphate (S1P) and targets S1P receptors 1, 3, 4, and 5. Recent reports indicate an association between long-term exposure to FTY720 and cases of cryptococcal infection. Here, we studied the effect of FTY720 and its derivative, BAF312, which only target S1P receptors 1 and 5, in a mouse model of cryptococcal infection. We found that treatment with FTY720, but not with BAF312, led to decreased survival and increased organ burden in mouse cryptococcal granulomas. Both FTY720 and BAF312 caused a profound CD4+ and CD8+ T cell depletion in blood and lungs but only treatment with FTY720 led to cryptococcal reactivation. Treatment with FTY720, but not with BAF312, was associated with disorganization of macrophages and with M2 polarization at the granuloma site. In a cell system, FTY720 decreased phagocytosis and production of reactive oxygen species by macrophages, a phenotype recapitulated in the S1pr3-/- knockout macrophages. Our results suggest that FTY720 reactivates cryptococcosis from the granuloma through a S1P receptor 3-mediated mechanism and support the rationale for development of more-specific receptor modulators for therapeutic use of MS.

Pharmacovigilance during treatment of multiple sclerosis: early recognition of CNS complications

An increasing number of highly effective disease-modifying therapies for people with multiple sclerosis (MS) have recently gained marketing approval. While the beneficial effects of these drugs in terms of clinical and imaging outcome measures is welcomed, these therapeutics are associated with substance-specific or group-specific adverse events that include severe and fatal complications. These adverse events comprise both infectious and non-infectious complications that can occur within, or outside of the central nervous system (CNS). Awareness and risk assessment strategies thus require interdisciplinary management, and robust clinical and paraclinical surveillance strategies. In this review, we discuss the current role of MRI in safety monitoring during pharmacovigilance of patients treated with (selective) immune suppressive therapies for MS. MRI, particularly brain MRI, has a pivotal role in the early diagnosis of CNS complications that potentially are severely debilitating and may even be lethal. Early recognition of such CNS complications may improve functional outcome and survival, and thus knowledge on MRI features of treatment-associated complications is of paramount importance to MS clinicians, but also of relevance to general neurologists and radiologists.

Safety of Newer Disease Modifying Therapies in Multiple Sclerosis

In the past decade, the therapeutic arsenal for multiple sclerosis has expanded greatly. Newer more potent disease modifying therapies (DMTs) with varying mechanisms of actions are increasingly used early in the disease course. These newer DMTs include oral therapies (teriflunomide, dimethyl fumarate, fingolimod, siponimod, ozanimod, and cladribine) and infusion therapies (natalizumab, alemtuzumab, and ocrelizumab), and are associated with better control of disease activity and long-term outcomes in patients with MS compared to older injectable therapies (interferon beta and glatiramer acetate). However, they are associated with safety concerns and subsequent monitoring requirements. Adverse events are initially observed in phase 2 and 3 clinical trials, and further long-term data are collected in phase 3 extension studies, case series, and post-marketing reports, which highlight the need to periodically re-evaluate and adjust monitoring strategies to optimize treatment safety in an individualized approach.

The risk of infection in patients with multiple sclerosis treated with disease-modifying therapies: A Delphi consensus statement

The risk of infection associated with immunomodulatory or immunosuppressive disease-modifying drugs (DMDs) in patients with multiple sclerosis (MS) has been increasingly addressed in recent scientific literature. A modified Delphi consensus process was conducted to develop clinically relevant, evidence-based recommendations to assist physicians with decision-making in relation to the risks of a wide range of infections associated with different DMDs in patients with MS. The current consensus statements, developed by a panel of experts (neurologists, infectious disease specialists, a gynaecologist and a neuroradiologist), address the risk of iatrogenic infections (opportunistic infections, including herpes and cryptococcal infections, candidiasis and listeria; progressive multifocal leukoencephalopathy; human papillomavirus and urinary tract infections; respiratory tract infections and tuberculosis; hepatitis and gastrointestinal infections) in patients with MS treated with different DMDs, as well as prevention strategies and surveillance strategies for the early identification of infections. In the discussion, more recent data emerged in the literature were taken into consideration. Recommended risk reduction and management strategies for infections include screening at diagnosis and before starting a new DMD, prophylaxis where appropriate, monitoring and early diagnosis.

Increased risk of disseminated cryptococcal infection in a patient with multiple sclerosis on fingolimod

Multiple sclerosis (MS) is the most common autoimmune disease of the central nervous system (CNS), with an estimated 2.3 million people being affected globally, and is a major cause of permanent disability. About 90 % of the affected patients with MS have relapsing-remitting type. Fingolimod became the first FDA approved oral drug in 2010 with an immunomodulating mechanism to control the relapse rates. However, since its introduction, increased cases of cryptococcal infections have been reported including meningoencephalitis and disseminated infections. Herein, we present the case of a 34-year-old-male with disseminated Cryptococcal and localized varicella zoster virus (VZV) coinfection to highlight the risk of opportunistic infections associated with the long-term use of fingolimod. The objective of this literature review is for clinicians to have a high index of suspicion for cryptococcal infections when dealing with MS patients on Fingolimod, especially those who present with neurological symptoms, as this mimics MS relapse.

Comparison of first-line and second-line use of fingolimod in relapsing MS: The open-label EARLIMS study

Background

Treatment of MS often begins with low-efficacy injectable disease-modifying therapy (iDMT).

Objectives

To compare the effect of fingolimod 0.5 mg/day on clinical, MRI, patient-reported, and safety outcomes, in treatment-naïve and previously treated (≥1 iDMT) patients with early MS.

Methods

EARLIMS was a multicentre, open-label, non-randomized, parallel-group phase 3 b/4 study in Australia and Spain. Patients with relapsing–remitting MS, Expanded Disability Status Scale (EDSS) score <4.0, and ≥1–5 years since diagnosis, received daily fingolimod for 48 weeks. The primary endpoint was annualized relapse rate (ARR).

Results

Of 347 patients enrolled at 51 sites (treatment-naïve, 200 [57.6%]; previously treated, 147 [42.4%]), 320 completed the study (treatment-naïve, 184 [92.0%]; previously treated, 136 [92.5%]), but the study remained underpowered (planned enrolment, n = 432). Fingolimod reduced ARR to similar levels in both treatment-naïve (mean ARR [95% confidence interval], 0.21 [0.14, 0.29]) and previously treated groups (0.30 [0.20, 0.41]; p = 0.1668). There were no new safety signals.

Conclusions

Fingolimod appeared equally effective as first- or second-line therapy in relapsing MS. There was a trend for better outcomes with fingolimod in treatment-naïve patients than in those previously treated with >1 iDMT.

Dimethyl fumarate treatment shifts the immune environment toward an anti-inflammatory cell profile while maintaining protective humoral immunity

Background:

Delayed-release dimethyl fumarate (DMF) demonstrates sustained efficacy and safety for relapsing forms of MS. Absolute lymphocyte count (ALC) is reduced initially, then stabilizes on treatment.

Objective:

PROCLAIM, a 96-week, prospective, open-label, phase 3b study, assessed lymphocyte subsets and immunoglobulin (Ig) levels during 48 and 96 weeks (W) of DMF treatment.

Methods:

Patients received 240 mg DMF BID. Endpoints: lymphocyte subset count changes (primary); Ig isotypes and ALC changes (secondary); adverse events and relationship between ALC changes and ARR/EDSS (exploratory); and neurofilament assessment (ad hoc).

Results:

Of 218 patients enrolled, 158 (72%) completed the study. Median ALC decreased 39% from baseline to W96 (BL–W96), stabilizing above the lower limit of normal (baseline: 1.82 × 10⁹/L; W48: 1.06 × 10⁹/L; W96: 1.05 × 10⁹/L). CD4 ⁺ and CD8 ⁺ T cells correlated highly with ALC from BL–W96 (p < 0.001). Relative to total T cells, naive CD4 ⁺ and CD8 ⁺ T cells increased, whereas CD4 ⁺ and CD8 ⁺ central and effector memory T cells decreased. Total IgA, IgG, IgM, and IgG1–4 subclass levels remained stable. Adverse event rates were similar across ALC subgroups. ARR, EDSS, and neurofilament were not correlated with ALCs.

Conclusion:

Lymphocyte decreases with DMF were maintained over treatment, yet immunoglobulins remained stable. No increase in infection incidence was observed in patients with or without lymphopenia.

Support:

Biogen

Primary cutaneous cryptococcal infection due to fingolimod - Induced lymphopenia with literature review

Cryptococcus. Neoformans (C. neoformans) is an encapsulated heterobasidiomycetous fungus responsible for opportunistic infections worldwide in immunocompromised patients. Clinical presentation ranges from asymptomatic respiratory tract colonization to disseminated infection in any human body part. The central nervous system (CNS) and pulmonary diseases garner most of the clinical attention. Secondary cutaneous cryptococcosis is an uncommon manifestation seen as a sentinel sign commonly in disseminated cryptococcal infection. Primary cutaneous cryptococcosis (PCC) is a rare manifestation seen in both immunocompromised and immunocompetent patients. It is a discrete infection with different epidemiological trends. Immunosuppressive therapy (corticosteroids, tacrolimus) predisposes a patient to acquire this clinical entity. We present a case of an elderly Caucasian male on fingolimod for relapsing-remitting multiple sclerosis with nonhealing scalp lesions for four years. He was a referral to our healthcare center for the presence of fungal elements seen on a scalp biopsy fungal stains. Final cultures returned positive for C. neoformans susceptible to fluconazole (MIC = 8 μg/mL). The CD4 count was 13 cells/uL, and workup for CNS and disseminated cryptococcal infection were negative. Fingolimod is an immunomodulator that acts on sphingosine 1-phosphate receptors, affecting the lymphocytes. Pubmed literature review revealed few case reports (< 5) with PCC in patients on fingolimod. To our knowledge, ours is the first case with scalp cryptococcosis, with the lowest CD4 count while being on fingolimod. No randomized controlled trial data exist for the treatment of PCC. Therapy initiated with oral luconazole for six months with significant improvement at three months.

Early drop of circulating T cells negatively correlates with the protective immune response to Yellow Fever vaccination

Lymphocyte recirculation within the human body is essential for efficient pathogen detection and immune responses. So far, immune cell migration has been investigated largely using ovine and murine models, with little evidence in humans. Here, we analyzed peripheral blood of healthy individuals following primary vaccination with the Yellow Fever vaccine YF-17D. We found that the number of leukocytes was transiently and sharply reduced in blood as detected on day 7 after vaccine administration. The T cell drop was restricted to cells expressing the lymph node-homing chemokine receptor CCR7. Interestingly, the vaccine-induced drop positively correlated with the expression of CD69 by the T cells before vaccination. This suggests that CCR7⁺ T cells are being trapped within the lymph nodes through CD69-induced suppression of egress. Strikingly, we further found that the T cell drop negatively correlated with CD8 T cell activation and with production of neutralizing antibodies. In conclusion, early and transient T cell depletion in blood negatively correlated with protective immune response events induced by YF-17D vaccination. Our data highlight baseline CD69 expression and early drop in T cells as potential biomarkers of the Yellow Fever vaccine response.

Cryptococcal meningoencephalitis in an IgG2-deficient patient with multiple sclerosis on fingolimod therapy for more than five years - case report

Background

Fingolimod (Gilenya®), a first-in-class sphingosine-1-phosphate receptor modulator is approved for the treatment of relapsing-remitting multiple sclerosis. Fingolimod-induced selective immunosuppression leads to an increased risk of opportunistic infections such as cryptococcosis. So far, a total of 8 cases of fingolimod-related cryptococcal meningoencephalitis have been published.

Case presentation

A 49-year-old female with relapsing-remitting multiple sclerosis presented with cephalgia, fever, confusion and generalized weakness. She had been on fingolimod therapy for the past 5.5 years. Clinical examination suggested meningoencephalitis and laboratory findings showed an IgG₂ deficiency. Initially no pathogen could be detected, but after 4 days Cryptococcus neoformans was found in the patient’s blood cultures leading to the diagnosis of cryptococcal meningoencephalitis. After antimycotic therapy, her symptoms improved and the patient was discharged.

Conclusion

MS patients on immunomodulatory  therapy are at constant risk for opportunistic infections. Cephalgia, fever and generalized weakness in combination with fingolimod-induced lymphopenia should be considered a red flag for cryptococcosis.

Cryptococcus neoformans var grubii meningoencephalitis in a patient on fingolimod for relapsing-remitting multiple sclerosis: Case report and review of published cases

INTRODUCTION

Fingolimod, a sphingosine-1-phosphate modulator used in the treatment of relapsing-remitting multiple sclerosis, has been associated with several cases of cryptococcosis.

CASE REPORT

We present a case of Cryptococcal meningoencephalitis attributable to Cryptococcus neoformans var. grubii, in a 58-year-old bird-keeper from Australia, after 7 years of fingolimod therapy. We discuss this in the context of previously reported cases, our understanding of fingolimod immune modulation, and known Cryptococcus pathobiology.

CONCLUSION

We suggest consideration of harm minimisation behaviours in patients requiring fingolimod, particularly in those with profound CD4 lymphopenia. Furthermore, we echo the call for improved post-marketing surveillance systems to determine the epidemiology of atypical infections with novel immunomodulatory treatments.

Case Report: Fingolimod and Cryptococcosis: Collision of Immunomodulation with Infectious Disease

The use of immunomodulatory and immunosuppressive therapies in multiple sclerosis (MS) has allowed practitioners to regulate MS disease activity, with the caveat that these potent medications may render patients susceptible to opportunistic infections. The approval of fingolimod presented the first oral option for relapsing MS. Since 2015, postmarketing safety data have documented several published cases of cryptococcal meningitis and disseminated cryptococcosis associated with fingolimod use. However, surveillance mechanisms for opportunistic infections and management of active demyelinating disease with ongoing infection have not been adequately addressed. We present a case of isolated pulmonary cryptococcosis with the use of fingolimod to highlight the hurdles in balancing efficacious disease-modifying therapies for MS while treating an opportunistic infection associated with that therapy.

Malassezia and Parkinson's Disease

Parkinson's disease (PD) is a common debilitating neurodegenerative disease caused by a loss of dopamine neurons in the substantia nigra within the central nervous system (CNS). The process leading to this neuronal loss is poorly understood. Seborrheic dermatitis (SD) is a common benign inflammatory condition of the skin which mainly affects lipid-rich regions of the head and trunk. SD is caused by over proliferation of the lipophilic fungus Malassezia. PD and SD are strongly associated. The increased PD risk following an SD diagnosis (OR = 1.69, 95% CI 1.36, 2.1; p < 0.001) reported by Tanner and colleagues remains unexplained. Malassezia were historically considered commensals confined to the skin. However, many recent studies report finding Malassezia in internal organs, including the CNS. This raises the possibility that Malassezia might be directly contributing to PD. Several lines of evidence support this hypothesis. AIDS is causally associated with both parkinsonism and SD, suggesting that weak T cell-mediated control of commensal microbes such as Malassezia might contribute to both. Genetic polymorphisms associated with PD (LRRK2, GBA, PINK1, SPG11, SNCA) increase availability of lipids within human cells, providing a suitable environment for Malassezia. Four LRRK2 polymorphisms which increase PD risk also increase Crohn's disease risk; Crohn's disease is strongly associated with an immune response against fungi, particularly Malassezia. Finally, Malassezia hypha formation and melanin synthesis are stimulated by L-DOPA, which could promote Malassezia invasiveness of dopamine neurons, and contribute to the accumulation of melanin in these neurons. Although Malassezia's presence in the substantia nigra remains to be confirmed, if Malassezia play a role in PD etiology, antifungal drugs should be tested as a possible therapeutic intervention.

Emerging Fungal Infections: New Patients, New Patterns, and New Pathogens

The landscape of clinical mycology is constantly changing. New therapies for malignant and autoimmune diseases have led to new risk factors for unusual mycoses. Invasive candidiasis is increasingly caused by non-albicans Candida spp., including C. auris, a multidrug-resistant yeast with the potential for nosocomial transmission that has rapidly spread globally. The use of mould-active antifungal prophylaxis in patients with cancer or transplantation has decreased the incidence of invasive fungal disease, but shifted the balance of mould disease in these patients to those from non-fumigatus Aspergillus species, Mucorales, and Scedosporium/Lomentospora spp. The agricultural application of triazole pesticides has driven an emergence of azole-resistant A. fumigatus in environmental and clinical isolates. The widespread use of topical antifungals with corticosteroids in India has resulted in Trichophyton mentagrophytes causing recalcitrant dermatophytosis. New dimorphic fungal pathogens have emerged, including Emergomyces, which cause disseminated mycoses globally, primarily in HIV infected patients, and Blastomyceshelicus and B. percursus, causes of atypical blastomycosis in western parts of North America and in Africa, respectively. In North America, regions of geographic risk for coccidioidomycosis, histoplasmosis, and blastomycosis have expanded, possibly related to climate change. In Brazil, zoonotic sporotrichosis caused by Sporothrix brasiliensis has emerged as an important disease of felines and people.

Estimating Residence Times of Lymphocytes in Ovine Lymph Nodes

The ability of lymphocytes to recirculate between blood and secondary lymphoid tissues such as lymph nodes (LNs) and spleen is well established. Sheep have been used as an experimental system to study lymphocyte recirculation for decades and multiple studies document accumulation and loss of intravenously (i.v.) transferred lymphocytes in efferent lymph of various ovine LNs. Yet, surprisingly little work has been done to accurately quantify the dynamics of lymphocyte exit from the LNs and to estimate the average residence times of lymphocytes in ovine LNs. In this work we developed a series of mathematical models based on fundamental principles of lymphocyte recirculation in the body under non-inflammatory (resting) conditions. Our analysis suggested that in sheep, recirculating lymphocytes spend on average 3 h in the spleen and 20 h in skin or gut-draining LNs with a distribution of residence times in LNs following a skewed gamma (lognormal-like) distribution. Our mathematical models also suggested an explanation for a puzzling observation of the long-term persistence of i.v. transferred lymphocytes in the efferent lymph of the prescapular LN (pLN); the model predicted that this is a natural consequence of long-term persistence of the transferred lymphocytes in circulation. We also found that lymphocytes isolated from the skin-draining pLN have a 2-fold increased entry rate into the pLN as opposed to the mesenteric (gut-draining) LN (mLN). Likewise, lymphocytes from mLN had a 3-fold increased entry rate into the mLN as opposed to entry rate into pLN. In contrast, these cannulation data could not be explained by preferential retention of cells in LNs of their origin. Taken together, our work illustrates the power of mathematical modeling in describing the kinetics of lymphocyte migration in sheep and provides quantitative estimates of lymphocyte residence times in ovine LNs.

Specific aspects of immunotherapy for multiple sclerosis in Switzerland: A structured commentary

More than a dozen substances are meanwhile available for the disease-modifying immunotherapy of multiple sclerosis (MS). However, for some substances, there is a clear difference between approval in Switzerland (Swissmedic) and neighboring countries (European Medicines Agency (EMA)). In addition, limitations imposed by the Swiss Federal Office of Public Health in the specialties list (SL) have significant effects on use in daily clinical practice. In the following, we present consensus recommendations, which were reviewed and agreed upon by the Scientific Advisory Board of the Swiss Multiple Sclerosis Society and the Swiss Neurological Society. We explicitly focus on practice-relevant differences in the approval of MS immunotherapies in Switzerland compared with the EMA area and discuss further limitations (SL) and their impact on the use in clinical practice. Immunotherapies with the same approval in Switzerland and the EMA area and symptomatic therapies are not discussed here.

Cryptococcal meningitis in a multiple sclerosis patient treated with Fingolimod: a case report and review of imaging findings

Fingolimod is an oral medication approved by the Food and Drug Administration in 2009 for the treatment of relapsing remitting multiple sclerosis (RRMS). Initial clinical trials did not show a significantly increased rate of serious infections with fingolimod therapy. However, a mildly increased risk of less serious infections, such as varicella zoster virus and herpes simplex virus, was reported. Recently, however, several instances of serious opportunistic infections have been reported. In the years following approval of fingolimod for use in multiple sclerosis (MS), seven cases of cryptococcal meningitis in patients undergoing treatment have been described in the literature. We present a 40-year old woman with RRMS on fingolimod therapy presenting with a rare case of cryptococcal meningitis exhibiting alterations of consciousness, which was initially diagnosed as an MS relapse.