JC virus granule cell neuronopathy associated with Ruxolitinib: A case report and review of the literature

Impact of JAK Inhibitors in Pediatric Patients with STAT1 Gain of Function (GOF) Mutations-10 Children and Review of the Literature

INTRODUCTION

Since the first description of gain of function (GOF) mutations in signal transducer and activator of transcription (STAT) 1, more than 300 patients have been described with a broad clinical phenotype including infections and severe immune dysregulation. Whilst Jak inhibitors (JAKinibs) have demonstrated benefits in several reported cases, their indications, dosing, and monitoring remain to be established.

METHODS

A retrospective, multicenter study recruiting pediatric patients with STAT1 GOF under JAKinib treatment was performed and, when applicable, compared with the available reports from the literature.

RESULTS

Ten children (median age 8.5 years (3-18), receiving JAKinibs (ruxolitinib (n = 9) and baricitinib (n = 1)) with a median follow-up of 18 months (2-42) from 6 inborn errors of immunity (IEI) reference centers were included. Clinical profile and JAKinib indications in our series were similar to the previously published 14 pediatric patients. 9/10 (our cohort) and 14/14 patients (previous reports) showed partial or complete responses. The median immune deficiency and dysregulation activity scores were 15.99 (5.2-40) pre and 7.55 (3-14.1) under therapy (p = 0.0078). Infection, considered a likely adverse event of JAKinib therapy, was observed in 1/10 patients; JAKinibs were stopped in 3/10 children, due to hepatotoxicity, pre-HSCT, and absence of response.

CONCLUSIONS

Our study supports the potentially beneficial use of JAKinibs in patients with STAT1 GOF, in line with previously published data. However, consensus regarding their indications and timing, dosing, treatment duration, and monitoring, as well as defining biomarkers to monitor clinical and immunological responses, remains to be determined, in form of international prospective multicenter studies using established IEI registries.

Role of JAK inhibitors in myeloproliferative neoplasms: current point of view and perspectives

Classic Philadelphia-negative myeloproliferative neoplasms (MPN) include polycythemia vera (PV), essential thrombocythemia (ET), and myelofibrosis (MF), classified as primary (PMF), or secondary to PV or ET. All MPN, regardless of the underlying driver mutation in JAK2/CALR/MPL, are invariably associated with dysregulation of JAK/STAT pathway. The discovery of JAK2V617F point mutation prompted the development of small molecules inhibitors of JAK tyrosine kinases (JAK inhibitors-JAKi). To date, among JAKi, ruxolitinib (RUX) and fedratinib (FEDR) are approved for intermediate and high-risk MF, and RUX is also an option for high-risk PV patients inadequately controlled by or intolerant to hydroxyurea. While not yet registered, pacritinib (PAC) and momelotinib (MMB), proved to be effective particularly in thrombocytopenic and anemic MF patients, respectively. In most cases, JAKi are effective in reducing splenomegaly and alleviating disease-related symptoms. However, almost 50% lose response by three years and dose-dependent toxicities may lead to suboptimal dosing or treatment discontinuation. To date, although not being disease-modifying agents, JAKi represent the therapeutic backbone particularly in MF patient. To optimize therapeutic strategies, many trials with drug combinations of JAKi with novel molecules are ongoing. This review critically discusses the role of JAKi in the modern management of patients with MPN.

Clinical drug therapies and biologicals currently used or in clinical trial to treat COVID-19

The potential emergence of SARS-CoV-2 variants capable of escaping vaccine-generated immune responses poses a looming threat to vaccination efforts and will likely prolong the duration of the COVID-19 pandemic. Additionally, the prevalence of beta coronaviruses circulating in animals and the precedent they have set in jumping into human populations indicates that they pose a continuous threat for future pandemics. Currently, only one therapeutic is approved by the U.S. Food and Drug Administration (FDA) for use in treating COVID-19, remdesivir, although other therapies are authorized for emergency use due to this pandemic being a public health emergency. In this review, twenty-four different treatments are discussed regarding their use against COVID-19 and any potential future coronavirus-associated illnesses. Their traditional use, mechanism of action against COVID-19, and efficacy in clinical trials are assessed. Six treatments evaluated are shown to significantly decrease mortality in clinical trials, and ten treatments have shown some form of clinical efficacy.

Progressive multifocal leukoencephalopathy successfully treated with mefloquine and literature review

Progressive multifocal leukoencephalopathy (PML) is an opportunistic infection due to reactivation of John Cunningham virus (JCV). The diagnosis depends on evidence from clinical, imaging, and virologic studies. When the cerebrospinal fluid shows a negative polymerase chain reaction result, brain biopsy is required to confirm the diagnosis. PML has no standard treatment except for immune reconstitution. The anti-JCV effect of mefloquine, however, is supported by some studies, and if brain biopsy is difficult, a mefloquine trial can be considered. We describe a case of possible PML successfully treated with mefloquine.

Neurologic Infections in Patients on Immunomodulatory and Immunosuppressive Therapies

PURPOSE OF REVIEW

Both broadly immunosuppressive medications and selective immunomodulatory agents that act on particular components of the immune system are increasingly used in the treatment of neurologic and non-neurologic diseases. These therapies predispose patients to particular infections, some of which may affect the nervous system. Therefore, familiarity with the clinical and radiologic features of neurologic infections associated with specific immunomodulatory therapies is of importance for the practicing neurologist. This article reviews these neuroinfectious conditions, as well as other neurologic complications unique to transplant recipients and other patients who are immunocompromised.

RECENT FINDINGS

Diagnosis of infectious pathogens in patients who are immunocompromised may be particularly challenging because a decreased immune response can lead to atypical imaging or laboratory findings. Next-generation sequencing and other novel diagnostic modalities may improve the rate of early identification of neurologic infections in patients who are immunocompromised and ultimately ameliorate outcomes in this vulnerable population.

SUMMARY

A broad range of bacterial, viral, fungal, and parasitic infections of the nervous system can complicate solid organ and hematopoietic cell transplantation as well as other forms of immunocompromise. In addition to neurologic infections, such patients are at risk of neurotoxic and neuroinflammatory complications related to immunomodulatory and immunosuppressive therapies. Early recognition of infectious and noninfectious complications of immunocompromise is essential to guide appropriate treatment, which can include antimicrobial therapy and, in some cases, withdrawal of the predisposing medication with a transition to an alternative regimen.

Cryptococcal fungemia and Mycobacterium haemophilum cellulitis in a patient receiving ruxolitinib: a case report and literature review

Background

Ruxolitinib is a novel oral Janus kinase inhibitor that is used for treatment of myeloproliferative diseases. It exhibits potent anti-inflammatory and immunosuppressive effects, and may increase the risk of opportunistic infections. Here, we report a rare case of Cryptococcus neoformans and Mycobacterium haemophilum coinfection in a myelofibrosis patient who was receiving ruxolitinib.

Case presentation

A 70-year-old Thai man who was diagnosed with JAK2V617F-mutation-positive primary myelofibrosis had been treated with ruxolitinib for 4 years. He presented with cellulitis at his left leg for 1 week. Physical examination revealed fever, dyspnea, desaturation, and sign of inflammation on the left leg and ulcers on the right foot. Blood cultures showed positive for C. neoformans. He was prescribed intravenous amphotericin B deoxycholate with a subsequent switch to liposomal amphotericin B due to the development of acute kidney injury. He developed new onset of fever after 1 month of antifungal treatment, and the lesion on his left leg had worsened. Biopsy of that skin lesion was sent for mycobacterial culture, and the result showed M. haemophilum. He was treated with levofloxacin, ethambutol, and rifampicin; however, the patient eventually developed septic shock and expired.

Conclusions

This is the first case of C. neoformans and M. haemophilum coinfection in a patient receiving ruxolitinib treatment. Although uncommon, clinicians should be aware of the potential for multiple opportunistic infections that may be caused by atypical pathogens in patients receiving ruxolitinib.