Clinical Characteristics and Outcomes of 101 Children with Hemophagocytic Lymphohistiocytosis: A Four-Year Single-Center Experience from Egypt

Clinical characteristics and prognostic analysis of pediatric hemophagocytic lymphohistiocytosis using lasso-logistic regression

This study aims to evaluate and predict mortality risks among pediatric patients with hemophagocytic lymphohistiocytosis (HLH). We conducted a retrospective analysis of pediatric patients with HLH diagnosed at the Affiliated Hospital of Zunyi Medical University between January 2012 and April 2023. Patients were divided into a death group and a survival group based on their outcomes. Risk factors for mortality were analyzed using a lasso-logistic regression model. This study included 142 pediatric patients with HLH, with a median age of 40.5 (14.75-84) months, of whom 78 (54.93%) were male. The overall mortality rate was 34.51%. Through lasso-logistic regression analysis, five independent prognostic factors were identified: concurrent central nervous system involvement, multiple organ dysfunction syndrome involving three or more organs, platelet count ≤ 42.5 × 109/L, activated partial thromboplastin time ≥ 54.05 s, and the utilization of blood purification in conjunction with the HLH-94/2004 treatment protocol. The predictive value of the lasso-logistic regression model is better than that of the traditional logistic regression model (AUC: 0.906 vs 0.811, P = 0.001). Subsequently, a lasso-logistic regression-based predictive model incorporating these identified risk factors was developed. Our lasso-logistic regression-based prediction model may help to identify high-risk patients with HLH early, thereby enabling the timely initiation of appropriate treatment interventions.

Hemophagocytic lymphohistiocytosis in Egyptian children: diagnosis, treatment challenges, and outcome

BACKGROUND

Hemophagocyticlymphohistiocytosis (HLH) is a spectrum of immune activation which could be genetically determined, or secondary to an underlying illness. Our aim was to present the clinico-genetic aspects of HLH among Egyptian children and to evaluate the patterns of reactivation and outcome with illustrations of overlap manifestations.

RESEARCH DESIGNAND METHODS

We retrospectively collected the data of 55 patients with HLH, registered at Ain Shams University Children's Hospital,Cairo, Egypt.

RESULTS

Median age at diagnosis was 19 months (range 2-180), 33 patients (60%) fulfilled the diagnostic HLH criteria at presentation. Fourteen (25.45%) patients had secondary HLH, 15 (27.27%) patients had genetically documented familial HLH (11 had variants in UNC13D gene and one in PRF1 gene), 3 had Griscelli and Chediak-Higashi syndromes. Sixteen patients (29.1%) had reactivations, 8 (50%) of them had molecularly confirmed HLH. We report the death of 40 patients, the median duration from the diagnosis to death of 5 months mostly due to disease activity.

CONCLUSIONS

This study confirms that the nonspecific signs and symptoms of HLH are challenging. Genetic testing, though expensive and sophisticated, is integral for the diagnosis. The difficulty in finding non-related donors for stem cell transplantation and the early reactivations are the causes of the inferior outcome.

Successful use of emapalumab in refractory hemophagocytic lymphohistiocytosis in a child with Chédiak-Higashi syndrome: a case report

BACKGROUND

Hemophagocytic lymphohistiocytosis is a life-threatening disease heralded by fever, cytopenia, hepatosplenomegaly, and multisystem organ failure. Its association with genetic mutations, infections, autoimmune disorders, and malignancies is widely reported.

CASE PRESENTATION

A 3-year-old male Arab Saudi patient with insignificant past medical history and parental consanguinity presented with abdominal distension of moderate severity and persistent fever despite receiving antibiotics. This was accompanied by hepatosplenomegaly and silvery hair. The clinical and biochemical profiles were suggestive of Chédiak-Higashi syndrome with hemophagocytic lymphohistiocytosis. The patient received the hemophagocytic lymphohistiocytosis-2004 chemotherapy protocol and had multiple hospital admissions mainly due to infections and febrile neutropenia. After achieving the initial remission, the patient's disease reactivated and did not respond to reinduction with the hemophagocytic lymphohistiocytosis-2004 protocol. Due to the disease reactivation and intolerance of conventional therapy, the patient commenced emapalumab. The patient was successfully salvaged and underwent an uneventful hematopoietic stem cell transplantation.

CONCLUSIONS

Novel agents such as emapalumab can be helpful for the management of refractory, recurrent, or progressive disease, while avoiding the toxicities of conventional therapy. Due to a paucity of available data on emapalumab, additional data are needed to establish its role in hemophagocytic lymphohistiocytosis treatment.

[Characteristic and prognosis of patients with non-EBV infection-associated hemophagocytic lymphohistiocytosis]

Objective: To explore the clinical characteristics and outcomes of patients with non-Epstein-Barr virus (EBV) infection-associated hemophagocytic lymphohistiocytosis (IAHLH) . Methods: Clinical data of 48 patients diagnosed with non-EBV IAHLH in Beijing Friendship Hospital from January 2015 to March 2021 were collected, and the clinical characteristics, treatment, curative effect and prognosis of the patients were analyzed retrospectively. Results: This study included 48 patients, 28 males and 20 females, with a median (range) age of 34.5 (2-74) years. Pathogens that cause IAHLH were as follows: virus (16 cases, 33.3%) , bacteria (17 cases, 35.4%) , parasitic agents (13 cases, 27.1%) , and fungi (2 cases, 4.2%) . The median time from onset to diagnosis of hemophagocytic syndrome (HLH) was 40 (10-160) days. The median (range) time duration from prodrome to the definite diagnosis of IAHLH was 67 (23-270) days. The clinical characteristics were fever (48 cases, 100%) , splenomegaly (34 cases, 70.8%) , cytopenia (38 cases, 79.1%) , elevated ferritin (45 cases, 93.8%) , elevated fasting triglyceride levels (7 cases, 14.6%) , hypofibrinogenemia (17 cases, 35.4%) , decrease natural killer cell activity (26 in 44 cases, 59.1%) , and elevated sCD25 (35 cases, 74.5%) . Twenty-five patients (52.1%) had adenopathy. Once a certain pathogen was identified as the causative factor of hemophagocytic lymphohistiocytosis (HLH) , cytotoxic agents and glucocorticoids were withdrawn, and specific pathogen-directed treatment was initiated. After treatment, 36 cases (75.0%) achieved complete response, and 14 of 15 patients (93.3%) with parasitic and fungal HLH got a response; however, the response rate of patient with bacterial and viral HLH was only 66.7% (22 of 33 patients) . The estimated 5-year overall survival rate was 72.3% (95%CI 50.3%-69.8%) . The adverse prognostic factors were total bilirubin over the upper limit of normal (OR=20.0, 95%CI 1.1-378.3, P=0.046) and pathogenic infection not fully controlled (OR=19.9, 95%CI 2.9-134.5, P=0.002) . Conclusion: Non-EBV IAHLH has a good prognosis. When diagnosed, cytotoxic agents and glucocorticoids should be tapered off, and pathogen-targeted therapy should be critically administered to clear the triggering infection.

Using a Minimal Parameter Set for Early Diagnosis of Hemophagocytic Lymphohistiocytosis in Non-European Children

Case series

Patients: Male, 4-day-old • Male, 29-day-old

Final Diagnosis: Hemophagocytic lymphohistiocytosis (HLH)

Symptoms: Fever

Medication: —

Clinical Procedure: —

Specialty: Hematology • Immunology

Screening of hemophagocytic lymphohistiocytosis in children with severe sepsis in pediatric intensive care

BACKGROUND

We sought to screen for clinical and laboratory features of hemophagocytic lymphohistiocytosis among pediatric patients with severe sepsis.

METHODS

We conducted a retrospective study that analyzed the clinical and laboratory data of 70 pediatric patients who died of severe sepsis. Medical records were revised for the presence of fever, splenomegaly, pancytopenia, hyperferritinemia, hypertriglyceridemia, and hypofibrinogenemia. Soluble CD25 was measured in stored samples.

RESULTS

Patients' ages ranged between 0.5 and 11 years with median (interquartile range) 2 (1-5). All patients had fever (≥38.5 °C) and pancytopenia, 58 (82.9%) hepatosplenomegaly, 36 (51.4%) lymphadenopathy, 37 (52.9%) had ferritin >500 ng/ml, 20 (28.6%) had fibrinogen <1.5 mg/ml, 14 (20%) had fasting triglycerides >264 mg/dl while 5 (7.1%) had soluble CD25 >2400 U/ml. Twenty-five (35.7%) patients fulfilled at least 5/6 of the hemophagocytic lymphohistiocytosis-2004 diagnostic criteria. Multivariate backward binary logistic regression analysis revealed lymphadenopathy as an independent predictor for hemophagocytic lymphohistiocytosis criteria fulfilment with odds ratio of 23.9. Fibrinogen had the best performance in discriminating hemophagocytic lymphohistiocytosis fulfilling from non-fulfilling groups (cut-off value: <1.8 mg/ml), followed by ferritin/erythrocyte sedimentation rate ratio (cut-off value: >17).

CONCLUSION

There is a significant clinical and laboratory overlap between hemophagocytic lymphohistiocytosis and severe sepsis, making the syndromes difficult to distinguish. The use of current hemophagocytic lymphohistiocytosis-2004 diagnostic criteria should be applied cautiously in those patients.