Brain abscess following rituximab infusion in a patient with pemphigus vulgaris

Listeriosis in a Metropolitan Hospital: Is Targeted Therapy a Risk Factor for Infection?

Targeted therapies are widely used for treatment of autoimmune diseases as well as solid organ and hematological malignancies. Various opportunistic infections have been described in patients on targeted therapies. Although case reports or a few case series of listeriosis have been reported to be associated with targeted therapy, most of the cases were related to anti-tumor necrosis factor-α monoclonal antibody. In this study, we describe the epidemiological and clinical profiles of listeriosis in a tertiary hospital in Shenzhen, a Southern Chinese metropolitan city in China. During the 9-year-and-6-month study period, a total of five cases of listeriosis were recorded and all of them had Listeria monocytogenes bacteremia. All five patients had predisposing factors, including corticosteroid (n = 3), targeted therapy (n = 2), pregnancy (n = 2) and anti-interferon gamma autoantibody (n = 1). The two patients who had targeted therapy during their course of cancer treatment received inhibitors of the epidermal growth factor receptor (EGFR)/human epidermal growth factor receptor 2 (HER2) pathway. The first one was a 52-year-old woman with metastatic adenocarcinoma of the lung. She was given gefitinib (EGFR tyrosine kinase inhibitor), osimertinib (third-generation EGFR tyrosine kinase inhibitor) and afatinib (tyrosine kinase inhibitor that can bind to EGFR, HER2 and HER4). The second one was a 40-year-old woman with carcinoma of the breast with brain metastasis. She was given trastuzumab (anti-HER2 monoclonal antibody) and lapatinib (dual tyrosine kinase inhibitor of the EGFR/HER2 pathway). These two patients represent the second and third reports of listeria infections associated with EGFR/HER2 pathway inhibitors in the literature. Targeted therapy is an important predisposing factor for listeriosis. Listeria infection is an important differential diagnosis in patients on targeted therapy who present with sepsis and/or central nervous system infection, and the use of antibiotic regimens that cover listeria is crucial for empirical treatment. Avoidance of high-risk food items in these patients is important for the prevention of listeriosis.

A review of reported infectious events following rituximab therapy in pemphigus patients

Pemphigus is a rare autoimmune blistering condition that used to be fatal before the introduction of corticosteroid (CS) and immunosuppressive agents. Rituximab is a monoclonal anti-CD-20 antibody that induces the pathologic B-cells apoptosis with significant efficacy in the treatment of pemphigus. The application of rituximab can lead to infectious events. We aim to review the reported infectious events in pemphigus patients who previously received rituximab and classify them based on the causative agents. A thorough search of PubMed was conducted using the keywords "rituximab," "pemphigus," "infection," "viral disease," "viral infection," "complication," "efficacy" and their combinations also applying their equivalent Mesh terms and including the references cited in each study. All studies that mentioned at least one infectious event were included. A total of 77 infectious events in 68 patients were reported in the literature out of which the most reported causative agent was viral but the most fatal one found to be bacterial. Although rituximab therapy has shown promising results in controlling pemphigus patients mainly the refractory cases, given possible fatal outcomes, we believe the medical profile of the patients before initiating the therapy warrants careful examination to search for any risk factors or predisposing conditions.

Cerebral Abscess Caused by Listeria monocytogenes: Case Report and Literature Review

BACKGROUND

 Listeria monocytogenes is an opportunistic gram-positive, facultative intracellular bacterium that causes invasive diseases mostly in pregnant women and immunosuppressed patients. Despite the predilection toward the central nervous system (CNS), it usually causes meningitis and meningoencephalitis, whereas brain abscesses are very uncommon.

CASE PRESENTATION

 We describe the case of a 69-year-old homeless patient with a brain abscess due to L. monocytogenes who was successfully treated surgically by a guided stereotactic aspiration and antibiotic therapy with ampicillin and gentamicin. Our patient was discharged after 4 weeks of therapy without neurologic deficits. Additionally, we provide a review of the literature of brain abscesses caused by L. monocytogenes.

CONCLUSIONS

 This case highlights the need to drain cerebral abscesses and culture pus to correctly treat patients with antibiotics, especially given the high mortality rate of this infectious entity.

Clinical and biological activity of rituximab in the treatment of pemphigus

B-cells are major effector cells in autoimmunity since they differentiate into plasmocytes that produce pathogenic auto-antibody such as anti-desmoglein antibodies in pemphigus patients. Major advances were obtained using whole B-cell depleting therapies including anti-CD20 antibodies in refractory pemphigus patients that lead to rituximab approval in pemphigus patients in EU and USA. This review summarizes the data supporting the efficacy of rituximab in pemphigus and provides an overview of the reported immunological changes underlying its therapeutic action. Short and long-term remission in pemphigus is explained by the removal of autoreactive B-cells involved in the production of pathogenic IgG auto-antibodies and by enhancement of the appearance of regulatory B-cells that could maintain long term immune tolerance.

Clinical Presentation and Cranial MRI Findings of Listeria monocytogenes Encephalitis: A Literature Review of Case Series

BACKGROUND

Listeria monocytogenes-associated encephalitis is a severe clinical condition that can also be seen in immunocompetent patients. Clinical manifestation and radiologic features of this entity need to be elaborated.

REVIEW SUMMARY

We searched the medical literature during the period spanning from 1991 to 2017 using the keyword "listeria AND [abscess odds ratio (OR) brainstem OR encephalit* OR magnetic* OR imaging*]." We included in the review well-documented adult cases with a definitive diagnosis and having magnetic resonance imaging data. Confusion, hemiparesis, cerebellar ataxia, facial paralysis, and gait disturbance were the most frequent findings, detected in >30% of patients during admission. The high rate of facial paralysis was of particular interest. T2 hyperintensity (80/82), contrast enhancement (60/82), and ring-enhancing lesions, which are considered as brain abscess, were found in 46/82 patients. The mortality and neurological sequel rates were 20% and 68%, respectively.

CONCLUSIONS

Listeria encephalitis is a severe disease and should be remembered in cases admitted with symptoms related to the brainstem and cranial nerve dysfunction. Cranial magnetic resonance imaging with brainstem and cerebellum involvements and contrast enhancement with or without abscess are particularly suggestive of the listeria-related infection.