Fatal West Nile Virus infection after rituximab/fludarabine--induced remission for non-Hodgkin's lymphoma

Hypogammaglobulinemia, late-onset neutropenia, and infections following rituximab

Rituximab is a chimeric anti-CD20 monoclonal antibody that targets CD20-expressing B lymphocytes, has a well-defined efficacy and safety profile, and is broadly used to treat a wide array of diseases. In this review, we cover the mechanism of action of rituximab and focus on hypogammaglobulinemia and late-onset neutropenia-2 immune effects secondary to rituximab-and subsequent infection. We review risk factors and highlight key considerations for immunologic monitoring and clinical management of rituximab-induced secondary immune deficiencies. In patients treated with rituximab, monitoring for hypogammaglobulinemia and infections may help to identify the subset of patients at high risk for developing poor B cell reconstitution, subsequent infections, and adverse complications. These patients may benefit from early interventions such as vaccination, antibacterial prophylaxis, and immunoglobulin replacement therapy. Systematic evaluation of immunoglobulin levels and peripheral B cell counts by flow cytometry, both at baseline and periodically after therapy, is recommended for monitoring. In addition, in those patients with prolonged hypogammaglobulinemia and increased infections after rituximab use, immunologic evaluation for inborn errors of immunity may be warranted to further risk stratification, increase monitoring, and assist in therapeutic decision-making. As the immunologic effects of rituximab are further elucidated, personalized approaches to minimize the risk of adverse reactions while maximizing benefit will allow for improved care of patients with decreased morbidity and mortality.

Severe Arboviral Neuroinvasive Disease in Patients on Rituximab Therapy: A Review

With increasing use of rituximab and other B-cell depleting monoclonal antibodies for multiple indications, infectious complications are being recognized. We summarize clinical findings of patients on rituximab with arboviral diseases identified through literature review or consultation with the Centers for Disease Control and Prevention. We identified 21 patients on recent rituximab therapy who were diagnosed with an arboviral disease caused by West Nile, tick-borne encephalitis, eastern equine encephalitis, Cache Valley, Jamestown Canyon, and Powassan viruses. All reported patients had neuroinvasive disease. The diagnosis of arboviral infection required molecular testing in 20 (95%) patients. Median illness duration was 36 days (range, 12 days to 1 year), and 15/19 (79%) patients died from their illness. Patients on rituximab with arboviral disease can have a severe or prolonged course with an absence of serologic response. Patients should be counseled about mosquito and tick bite prevention when receiving rituximab and other B-cell depleting therapies.

Peripheral B Cell Deficiency and Predisposition to Viral Infections: The Paradigm of Immune Deficiencies

In the era of COVID-19, understanding how our immune system responds to viral infections is more pertinent than ever. Immunodeficiencies with very low or absent B cells offer a valuable model to study the role of humoral immunity against these types of infection. This review looks at the available evidence on viral infections in patients with B cell alymphocytosis, in particular those with X-linked agammaglobulinemia (XLA), Good’s syndrome, post monoclonal-antibody therapy and certain patients with Common Variable Immune Deficiency (CVID). Viral infections are not as infrequent as previously thought in these conditions and individuals with very low circulating B cells seem to be predisposed to an adverse outcome. Particularly in the case of SARS-CoV2 infection, mounting evidence suggests that peripheral B cell alymphocytosis is linked to a poor prognosis.

Infectious Complications of Biological and Small Molecule Targeted Immunomodulatory Therapies

The past 2 decades have seen a revolution in our approach to therapeutic immunosuppression. We have moved from relying on broadly active traditional medications, such as prednisolone or methotrexate, toward more specific agents that often target a single receptor, cytokine, or cell type, using monoclonal antibodies, fusion proteins, or targeted small molecules. This change has transformed the treatment of many conditions, including rheumatoid arthritis, cancers, asthma, and inflammatory bowel disease, but along with the benefits have come risks. Contrary to the hope that these more specific agents would have minimal and predictable infectious sequelae, infectious complications have emerged as a major stumbling block for many of these agents. Furthermore, the growing number and complexity of available biologic agents makes it difficult for clinicians to maintain current knowledge, and most review articles focus on a particular target disease or class of agent. In this article, we review the current state of knowledge about infectious complications of biologic and small molecule immunomodulatory agents, aiming to create a single resource relevant to a broad range of clinicians and researchers. For each of 19 classes of agent, we discuss the mechanism of action, the risk and types of infectious complications, and recommendations for prevention of infection.

West Nile virus neuroinvasive disease associated with rituximab therapy

West Nile virus neuroinvasive disease (WNVND) manifests with meningitis, encephalitis, and/or acute flaccid paralysis. It represents less than 1% of the clinical syndromes associated with West Nile virus (WNV) infection in immunocompetent patients. Immunosuppressive therapy is associated with increased risk of WNVND and worse prognosis. We present a patient with WNVND during therapy with rituximab, and a review of the literature for previous similar cases with the goal to describe the clinical spectrum of WNVND in patients treated specifically with rituximab. Our review indicates that the most common initial complaints are fever and altered mental status, brain magnetic resonance imaging often shows bilateral thalamic hyperintensities, and cerebrospinal analysis consistently reveals mild lymphocytic pleocytosis with elevated protein, positive WNV polymerase chain reaction, and negative WNV antibodies. Treatment is usually supportive care, with intravenous immunoglobulins (IVIG) plus corticosteroids and WNV-specific IVIG also used. The disease is usually fatal despite intervention. Our patient's presentation was very similar to prior reports, however demonstrated spontaneous improvement with supportive management only. WNVND is a rare and serious infection with poor prognosis when associated with rituximab therapy. Diagnosis is complicated by absent or delayed development of antibodies. The presence of bilateral thalamic involvement is a diagnostic clue for WNVND. There is insufficient evidence to recommend the use of corticosteroids or IVIG.

Arenaviruses and West Nile Virus in solid organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the epidemiology, diagnosis, prevention, and management of infection due to Arenaviruses and West Nile Virus (WNV) in the pre- and post-transplant period. Arenaviruses and WNV have been identified as causes of both donor-derived and post-transplant infection. Most data related to these infections have been published in case reports and case series. Transplant recipients may become infected with Arenaviruses if they, or their donors, are exposed to wild rodents or infected pet rodents. Lymphocytic choriomeningitis virus is the most commonly recognized Arenavirus among transplant recipients and should be considered when transplant recipients present with fever, hepatitis, meningitis/encephalitis, and/or multisystem organ failure. WNV is a mosquito-borne virus, and as such, its incidence varies yearly depending on environmental conditions. WNV in transplant recipients typically presents with fever, myalgias, and rash; approximately one in 40 develop neuroinvasive disease. Due to its morbidity, the Organ Procurement and Transplantation Network recently mandated that transplant centers screen living donors for WNV infection in endemic areas. Little is known about the optimal treatment of Arenaviruses or WNV; reduction in immunosuppression and supportive care are the mainstays of management at present.

West Nile Virus Encephalitis in Haematological Setting: Report of Two Cases and a Brief Review of the Literature

West Nile virus is a zoonotic agent causing life-threatening encephalitis in a proportion of infected patients. Older age, immunosuppression, and mutations in specific host genes (e.g., CCR5 delta-32 mutation) predispose to neuroinvasive infection. We report on two cases of severe West Nile encephalitis in recently-treated, different-aged, chronic lymphocytic leukemia patients. Both patients developed high-grade fever associated with severe neurological impairment. The younger one harboured germ-line CCR5 delta-32 mutation, which might have played a role in the pathogenesis of its neuroinvasive manifestations.

West Nile Encephalitis, an Unusual Infection in a Chronic Lymphocytic Leukemia Patient

CNS involvement by CLL is a rare occurrence, usually happening in the context of a transformation to a more aggressive lymphoma in what is known as Richter's transformation. We report a patient with active CLL who developed confusion and was found to have West Nile encephalitis that initially mimicked CNS involvement by CLL. The patient recovered with supportive treatment and later restarted ibrutinib therapy. This case illustrates the importance of maintaining a broad differential among cancer patients with new onset confusion as well as that of questioning malignant infiltration of CNS when there is concomitant active CNS infection.

Zika virus: a cause of concern in transplantation?

PURPOSE OF REVIEW

Worldwide, the number of countries reporting Zika virus (ZKV) infection continues to increase. Although 80% of cases are asymptomatic, ZKV has been identified as a neurotropic virus associated with congenital microcephaly, Guillain-Barre' syndrome, and meningoencephalitis. Until recently, infection in transplant recipients has not been identified. This study will review the existing literature on ZKV infection, laboratory testing, and management in transplant recipients.

RECENT FINDINGS

Donor-derived transfusion of contaminated blood products and naturally occurring ZKV infections have been recently reported in solid organ and stem cell transplant recipients, ranging from asymptomatic infections to meningoencephalitis. Interpretation of diagnostic testing of ZKV is evolving, with prolonged viral shedding identified in blood, semen, and urine of unclear significance. Serologic testing may be associated with cross-reactivity with other flaviviridae, requiring plaque reduction neutralization testing for confirmation. Thus far, donor screening guidelines for transplantation have not been established.

SUMMARY

The study reviews the limited existing literature in transplant recipients infected with ZKV, available laboratory testing and management. Ultimately, guidelines are needed for donor screening from high-risk areas, interpretation of studies and management of infected patients to ensure safe transplantation.

Fatal Eastern Equine Encephalitis in a Patient on Maintenance Rituximab: A Case Report

A 63-year-old woman on rituximab maintenance for follicular lymphoma presented with headaches, vomiting, and fever, and was diagnosed with eastern equine encephalomyelitis by cerebrospinal fluid polymerase chain reaction. Eastern equine encephalomyelitis immunoglobulin (Ig)G/IgM remained negative due to rituximab treatment, and magnetic resonance imaging showed minimal abnormalities, making this a diagnostically challenging case. Despite therapy with intravenous Ig, the patient rapidly declined and died on hospital day 12. Autopsy revealed perivascular and parenchymal chronic inflammation, with an absence of B lymphocytes, and virally infected neurons throughout the central nervous system.

West Nile Virus Central Nervous System Infection in Patients Treated With Rituximab: Implications for Diagnosis and Prognosis, With a Review of Literature

The spectrum of West Nile virus (WNV) infection continues to be elucidated. Many cases of WNV are asymptomatic; however, in immunocompromised patients, symptoms are more likely to be severe. We describe fatal WNV central nervous system disease in lymphoma patients who received rituximab, blunting the inflammatory response and complicating diagnosis.

West Nile Virus Infection in the Immunocompromised Patient

West Nile virus infection has become the predominant cause of flavivirus-associated encephalitis in the US. While 80 % of infected individuals are asymptomatic, 20 % develop symptoms including fever, headache, transient rash and gastrointestinal symptoms. Among the immunocompetent population, 1 in 150 develop neuroinvasive disease characterized by acute flaccid paralysis, Parkinsonian cogwheel rigidity, meningitis, encephalitis, meningoencephalitis and asymmetric muscle weakness (Mostashari et al. in Lancet 358:261-264, 2001). In the immunocompromised population such as transplant recipients and HIV-infected and chemotherapy patients, the incidence of neuroinvasive disease may be increased. The largest population studied is recipients of solid organ transplants, with data on both donor-derived and naturally occurring transmissions. The risk of neuroinvasive disease in donor-derived infection is estimated to be between 50 % and 75 % while in those with mosquito-borne transmission the risk is estimated at 40 % of those infected (Kumar et al. in Am J Transplant 4:1883-1888, 2004). With significant morbidity associated with donor transmission, specific pretransplant screening recommendations are reviewed. Treatment includes supportive care and consideration for the use of intravenous immunoglobulin.

Risk of infection in patients with lymphoma receiving rituximab: systematic review and meta-analysis

BACKGROUND

The addition of Rituximab (R) to standard chemotherapy (C) has been reported to improve the end of treatment outcome in patients affected by CD-20 positive malignant lymphomas (CD20+ ML). Nevertheless, given the profound and prolonged immunosuppression produced by R there are concerns that severe infections may arise. A systematic review and meta-analysis were performed to determine whether or not the addition of R to C may increase the risk of severe infections in adults undergoing induction therapy for CD20+ ML.

METHODS

Only randomised controlled trials comparing R-C to C standard alone in adult patients with CD20+ ML were included. Meta-analysis was performed on overall incidence of severe infection, risk of dying as the consequence of infection, risk of febrile neutropenia, risk of severe leucopenia, risk of severe granulocytopenia and overall response assuming a fixed effect model. Heterogeneity was investigated, if present and I2 >20%, according to several predefined baseline characteristics of the study populations.

RESULTS

Several relevant results have emerged. First, the addition of R to standard C does not increase the overall risk of severe infections (RR = 1.00; 95% CI 0.87 to 1.14) nor does it increase the risk of dying as a consequence of infection (RR = 1.60; 95% CI 0.68 to 3.75). Second, we confirmed that the addition of R to standard C increases the proportion of overall response (RR = 1.12; 95% CI 1.09 to 1.15), but it also increases the risk of severe leucopenia (RR = 1.24; 95% CI 1.12 to 1.37) and granulocytopenia (RR = 1.07; 95% CI 1.02 to 1.12).

CONCLUSIONS

R-C is superior to standard C in terms of overall response and it does not increase the overall incidence of severe infection. However, data on special groups of patients (for example, HIV positive subjects and HBV carriers) are lacking. In our opinion more studies are needed to explore the potential effect of R on silent and chronic viral infections.

Does rituximab increase the incidence of infectious complications? A narrative review

BACKGROUND

Rituximab has increasingly been used for the treatment of hematological malignancies and autoimmune diseases, and its efficacy and safety are well established. Although clinical trials have shown conflicting results regarding the association of rituximab with infections, an increased incidence of infections has recently been reported in patients with lymphomas being treated with rituximab. However, clinical experience regarding the association of rituximab with different types of infection is lacking and this association has not been established in patients with rheumatoid arthritis.

METHODS

All previous studies included in our literature review were found using a PubMed, EMBASE, and Cochrane database search of the English-language medical literature applying the terms 'rituximab', 'monoclonal antibodies', 'infections', 'infectious complications', and combinations of these terms. In addition, the references cited in these articles were examined to identify additional reports.

RESULTS

We performed separate analyses of data regarding the association of rituximab with infection in (1) patients with hematological malignancies, (2) patients with autoimmune disorders, and (3) transplant patients. Recent data show that rituximab maintenance therapy significantly increases the risk of both infection and neutropenia in patients with lymphoma or other hematological malignancies. On the other hand, data available to date do not indicate an increased risk of infections when using rituximab compared with concurrent control treatments in patients with rheumatoid arthritis. However, there is a lack of sufficient long-term data to allow such a statement to be definitively made, and caution regarding infections should continue to be exercised, especially in patients who have received repeated courses of rituximab, are receiving other immunosuppressants concurrently, and in those whose immunoglobulin levels have fallen below the normal range. Few data are available concerning the risk of organ transplant recipients developing infections following rituximab therapy. Data from case reports, case series, and retrospective studies correlate rituximab use with the development of a variety of infections in transplant patients.

CONCLUSIONS

Further studies are needed to clarify the association of rituximab with infection. Physicians and patients should be educated about the association of rituximab with infectious complications. Monitoring of absolute neutrophil count and immunoglobulin levels and the identification of high-risk groups for the development of infectious complications, with timely vaccination of these groups, are clearly needed.

Rituximab-associated infections

After more than 10 years of use, rituximab has proven to be remarkably safe. However, accumulated evidence now suggests that under some circumstances it may significantly increase the risk of infections. This risk is difficult to quantify because of confounding factors (namely, concomitant use of immunosuppressive or chemotherapeutic agents and underlying conditions), as well as under-reporting. Increased number of infections has been documented in patients treated with maintenance rituximab for low-grade lymphoma and in patients with concomitant severe immunodeficiency, whether caused by human immunodeficiency virus (HIV) infection or immunosuppressive agents like fludarabine. From the practical standpoint, the most important infection is hepatitis B reactivation, which may be delayed and result in fulminant liver failure and death. Special care should be placed on screening for hepatitis B virus (HBV) and preemptive antiviral treatment. Some investigators have reported an increase in Pneumocystis pneumonia. Finally, there is increasing evidence of a possible association with progressive multifocal leukoencephalopathy (PML), a lethal encephalitis caused by the polyomavirus JC. This review enumerates the described infectious complications, summarizes the possible underlying mechanisms of the increased risk, and makes recommendations regarding prevention, diagnosis and management.

The late adverse events of rituximab therapy--rare but there!

Rituximab, an anti CD20 monoclonal antibody, has now become a cornerstone in the treatment of many CD20 positive hematological malignancies and a variety of autoimmune disorders. In contrast to the acute allergic and cytokine associated reactions, late adverse events of rituximab are indeed uncommon but at the same time probably under-reported. In this review, we detail late adverse events reported since its use in hemato-oncological neoplasias and other disorders. These adverse events include the development of late-onset neutropenia, defects of immune reconstitution with associated immune compromise, infections, progressive multifocal leukoencephalopathy, reactivation of hepatitis, intestinal perforation and interstitial pneumonitis. Possible mechanisms involved in rituximab-associated complications and the pathogenesis of these adverse effects are reviewed and discussed. Evidence based graded recommendations for the management of these adverse effects are proposed.

Impact of rituximab-associated B-cell defects on West Nile virus meningoencephalitis in solid organ transplant recipients

Evidence suggests that West Nile virus (WNV) neuroinvasive disease occurs more frequently in both solid organ and human stem cell transplant recipients. The effect of concomitant anti-B-cell therapy with rituximab, a CD20(+) monoclonal antibody, on WNV infection in this population, however, has not been reported. We describe a case of a patient with alpha-1-antitrypsin deficiency who underwent single lung transplantation in 2005 and was maintained on tacrolimus, cytoxan and prednisone. More recently, she had received two courses of rituximab for recurrent A2-A3 grade rejection with concomitant capillaritis and presented six months later with rapid, fulminant WNV meningoencephalitis. Her diagnosis was made by cerebrospinal fluid (CSF) PCR but serum and CSF WNV IgM and IgG remained negative. She received WNV-specific hyperimmune globulin (Omr-Ig-Am) through a compassionate protocol. She experienced a rapidly progressive and devastating neurological course despite treatment and died three wk after onset of her symptoms. Autopsy revealed extensive meningoencephalomyelitis.

Risk factors for infection in haematology patients treated with rituximab

OBJECTIVES

Although rituximab therapy is not considered to be closely associated with infection, there have been reports of serious infections in patients treated with rituximab. We performed a statistical retrospective analysis to clarify the risk factors for infection in patients receiving rituximab therapy.

METHODS

A retrospective study of data from clinical records was performed that targeted haematology patients treated at our university hospital between April 2003 and October 2006. We selected 63 patients with CD20-positive lymphoma whose peripheral blood immunoglobulin levels had been measured within 6 months before and after rituximab therapy. Logistic regression analysis was used to investigate the risk factors for serious infection in these patients.

RESULTS

The three risk factors identified were: 1) reduction in IgM after administration of rituximab [odds ratio (OR) = 1.032, confidence interval (CI) = 1.007-1.057; P = 0.009], 2) duration of rituximab therapy [OR = 0.962, CI = 0.932-0.994; P = 0.021] and 3) G-CSF administration [OR = 4.825, CI = 1.411-16.495; P = 0.012].

CONCLUSIONS

Rituximab therapy may be associated with infection, indicating the need for sequential monitoring of IgM levels and identification of the optimal interval between rituximab cycles.

Rituximab-related viral infections in lymphoma patients

Recently, a human/mouse chimeric monoclonal antibody, rituximab, has been successfully used to treat cases of B-cell non-Hodgkin's lymphoma and some autoimmune diseases. However, several viral infections related to rituximab have been reported in the literature, but were not well characterized. To further investigate this topic, relevant English language studies were identified through Medline. There were 64 previously reported cases of serious viral infection after rituximab treatment. The median age of the cases was 61 years (range: 21 - 79). The median time period from the start of rituximab treatment to viral infection diagnosis was 5.0 months (range: 1 - 20). The most frequently experienced viral infections were hepatitis B virus (HBV) (39.1%, n = 25), cytomegalovirus infection (CMV) (23.4%, n = 15), varicella-zoster virus (VZV) (9.4%, n = 6), and others (28.1%, n = 18). Of the patients with HBV infections, 13 (52.0%) died due to hepatic failure. Among the 39 cases that had viral infections other than HBV, 13 died due to these specific infections. In this study, about 50% of the rituximab-related HBV infections resulted in death, whereas this was the case in only 33% of the cases with other infections. Close monitoring for viral infection, particularly HBV and CMV, in patients treated with rituximab should be recommended.

West Nile encephalitis, status epilepticus and West Nile pneumonia in a renal transplant patient

West Nile neuroinvasive disease (WNND) represents a small fraction of cases of West Nile Virus (WNV) infection. Organ transplantation is associated with increased risk of acquiring WNND. We report a patient with living-related renal transplantation who developed unusual manifestations of WNND. First, fatal status epilepticus unresponsive to pentobarbital ensued. Status epilepticus from WNV has been described very rarely in the medical literature. Second, this patient grew WNV on broncho-alveolar lavage samples. To our knowledge, this is the first case of culture positive West Nile pneumonia. Third, the finding in cerebrospinal fluid (CSF) of a negative West Nile immunoglobulin M (IgM) and a positive West Nile polymerase chain reaction is striking. It is consistent with a high-viral burden and impaired immune response. This finding raises questions about the appropriateness of relying on CSF IgM assays to rapidly diagnose WNV encephalitis in organ transplant patients, as has been recommended.