Hemophagocytic lymphohistiocytosis caused by systemic herpes simplex virus type 1 infection: Successful treatment with dexamethasone palmitate

Hemophagocytic Lymphohistiocytosis Triggered by Herpes Simplex Virus 1 and 2: A Narrative Review

Introduction: Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening syndrome characterized by an uncontrolled hyperinflammatory reaction. HLH is classified into primary (familial) and secondary (acquired). Secondary HLH is commonly triggered by infections, with viral infections being a leading cause. Its epidemiology and clinical features in cases associated with herpes simplex virus 1 and 2 remain underexplored. This study aimed to review all previously described cases of HSV-1 or -2-triggered HLH and provide information about this syndrome's epidemiology, microbiology, clinical characteristics, treatment, and outcomes. Methods: A narrative review was performed based on a search in PubMed, the Cochrane Library, and Scopus. Studies published until 27 April 2024 providing relevant data for HLH due to HSV 1 and 2 in humans were included. Results: We identified 29 eligible studies reporting HLH due to HSV 1 and 2, involving 34 patients. Half of them were adults, and half were neonates. Fever and splenomegaly were the most common clinical findings. Most patients were diagnosed with HSV-1 (64.7%), with PCR being the primary diagnostic method. The median duration of in-hospital treatment was 21 days, with acyclovir and steroids being the mainstays of therapy. The overall mortality rate was 41.2%, and AST levels emerged as an independent predictor of mortality. Conclusions: Our findings underscore the need for heightened awareness surrounding HLH triggered by HSV 1 and 2 and the importance of prompt diagnosis and tailored treatment approaches.

Neonatal hemophagocytic lymphohistiocytosis: A meta-analysis of 205 cases

BACKGROUND

Neonatal hemophagocytic lymphohistiocytosis (nHLH), defined as HLH that presents in the first month of life, is clinically devastating. There have been few large descriptive studies of nHLH.

OBJECTIVES

The objective of this study was to perform a meta-analysis of published cases of nHLH.

METHODS

A comprehensive literature database search was performed. Cases of HLH were eligible for inclusion if clinical analysis was performed at age ≤30 days. Up to 70 variables were extracted from each case.

RESULTS

A total of 544 studies were assessed for eligibility, and 205 cases of nHLH from 142 articles were included. The median age of symptom onset was day of life 3 (interquartile range [IQR]: 0-11, n = 141). Median age at diagnosis was day of life 15 (IQR: 6-27, n = 87). Causes of HLH included familial HLH (48%, n = 99/205), infection (26%, n = 53/205), unknown (17%, n = 35/205), macrophage activation syndrome/rheumatologic (2.9%, n = 4/205), primary immune deficiency (2.0%, n = 5/205), inborn errors of metabolism (2.4%, n = 5/205), and malignancy (2.0%, n = 4/205). Fever was absent in 19% (n = 28/147) of all neonates and 39% (n = 15/38) of preterm neonates. Bicytopenia was absent in 26% (n = 47/183) of patients. Central nervous system (CNS) manifestations were reported in 63% of cases (n = 64/102). Liver injury (68%, n = 91/134) and/or liver failure (24%, n = 32/134) were common. Flow cytometry was performed in 22% (n = 45/205) of cases. Many patients (63%, n = 121/193) died within the period of reporting. Discernable values for HLH diagnostic criteria were reported between 30% and 83% of the time.

CONCLUSIONS

Evaluation of nHLH requires rapid testing for a wide range of differential diagnoses. HLH diagnostic criteria such as fever and bicytopenia may not occur as frequently in the neonatal population as in older pediatric populations. Neurologic and hepatic manifestations frequently occur in the neonatal population. Current reports of nHLH suggest a high mortality rate. Future publications containing data on nHLH should improve reporting quality by reporting all clinically relevant data.

Tuberculosis-Associated HLH in an 8-Month-Old Infant: A Case Report and Review

Hemophagocytic lymphohistiocytosis (HLH) is a rare immunological disease, which can be mistaken for sepsis easily. Among the infectious causes that may trigger secondary HLH, tuberculosis (TBC), a rather rare pathogen nowadays, is typical. To our knowledge, this is the first case report of an infant suffering from TBC-associated HLH-induced acute respiratory failure who was treated successfully using extracorporeal membrane oxygenation. An 8-month-old boy with fever (over the last 8 wk) and pancytopenia was transferred to our institution with acute respiratory failure and for extracorporeal membrane oxygenation therapy. Bone marrow biopsy revealed hemophagocytosis. Immunological work-up for familial HLH was negative. In a desperate search for the cause of secondary HLH, an interferon-gamma release assay for TBC returned positive. However, microscopy for acid-fast bacteria as well as polymerase chain reaction for TBC were initially negative. Despite this, the child was treated with tuberculostatic therapy. TBC was finally confirmed. The child remained on extracorporeal membrane oxygenation for 28 d. Further work-up showed typical lesions of disseminated TBC. The mother was identified as the source of TBC. The boy presents with mild sequelae (fine motor skills). In infants with suspected septicemia, TBC should be considered as differential diagnosis even if the results are initially negative.

Acquired Hemophagocytic Lymphohistiocytosis Associated With Disseminated Herpes Simplex Virus in Immunocompetent Host

We report the case of an immunocompetent young woman who developed multisystem organ failure following herpes simplex virus type 2 and hemophagocytic lymphohistiocytosis. Despite intravenous acyclovir and supportive measures, she rapidly progressed to acute liver failure and died before she could receive orthotopic liver transplant.

V348I mutation in UL23 gene of human herpesvirus 1 in a case of herpetic hepatitis and haemophagocytic lymphohistiocytosis

We herein report the case of a young immunocompetent adult patient with a rapidly fatal haemophagocytic lymphohistiocytosis syndrome related to human herpesvirus 1 (HHV-1) infection, with herpetic hepatitis and persistent high-level viraemia despite treatment with acyclovir. Haemophagocytic lymphohistiocytosis was confirmed in the patient's spleen and bone marrow. HHV-1 DNA was extracted from whole blood and liver biopsy and the UL23 gene was sequenced. A V348I natural polymorphism of the TK protein was found in blood and liver specimens. Further studies are needed to investigate the role of this polymorphism in the development of systemic immune dysregulation.

Limethason reduces airway inflammation in a murine model of ovalbumin-induced chronic asthma without causing side effects

Airway inflammation is the major pathological feature of asthma. Thus, the current therapeutic strategy for asthma is to control inflammation. Limethason, an anti-inflammation drug, is widely used in rheumatoid arthritis treatment. The aim of the present study was to detect the anti-inflammatory effect and side effects of limethason on airways that were sensitized with ovalbumin in a murine model of chronic asthma. In the present study, BALB/c mice were sensitized with ovalbumin. Airway hyperresponsiveness was estimated, and hematoxylin and eosin staining, Periodic acid-Schiff staining and bronchoalveolar lavage were used to detect the effect on chronic asthma. Limethason effectively reduced airway hyperresponsiveness, and inhibited inflammatory cell infiltration and mucus secretion. Bronchoalveolar lavage fluid analysis revealed that limethason suppressed levels of airway eosinophils. In the period of treatment, limethason exhibited no influence on morphology of the femoral head, bone mineral content or bone mineral density, which were detected by histological studies and dual-energy X-ray absorptiometry. The index of liver, spleen, kidney, gastrocnemius and brown adipose tissue also demonstrated that limethason had no adverse effects on organs and tissues. The present study revealed that limethason could effectively reduce inflammation in an asthma mouse model without side effects. Therefore, limethason may have therapeutic potential for treating chronic asthma clinically.