Diagnostic Challenges in Hemophagocytic Lymphohistiocytosis, a Rare, Potentially Fatal Disease: Two Case Studies.

Hemophagocytic lymphohistiocytosis (HLH) is a rare, and potentially fatal, syndrome, characterized by immune system dysregulation, with excessive activation of the macrophages and cytotoxic T cells. It can be classified into primary (genetic) and secondary (acquired) forms. HLH presents with fever, hepatosplenomegaly, cytopenia, and hyperferritinemia, with involvement of various organs. The initial symptoms of HLH are non-specific, but as, if untreated, it can progress rapidly to multiorgan failure, timely diagnosis is essential. We present here two cases of HLH in infants that illustrate the importance of early diagnosis and appropriate treatment, along with a short review of HLH.

The Role of Mannose-Binding Lectin and Inflammatory Markers in Establishing the Course and Prognosis of Community-Acquired Pneumonia in Children.

BACKGROUND: Community-acquired pneumonia (CAP) is one of the most significant childhood diseases worldwide and a leading infectious cause of death in children. This study aimed to evaluate the prognostic value of the inflammatory markers-C-reactive protein (CRP) and procalcitonin (PCT)-and the polymorphic glycoprotein mannose-binding lectin (MBL), deficiency of which is associated with severe infections, in the determination of the optimal type and timing of therapeutic intervention for CAP in childhood. METHODS: Retrospective evaluation was conducted on a cohort of 204 children aged 4 months-17 years hospitalized with CAP. Their levels of CRP, PCT, and MBL were assessed for their association with a variety of outcomes, including the incidence of local and systemic complications, admission to the ICU, duration of antibiotic treatment and hospital stay, and death. RESULTS: CRP and PCT proved to be better predictors of complications of CAP than MBL. The area under the curve (AUC) value was highest for PCT as a predictor of systemic complications (AUC = 0.931, 95%CI 0.895-0.967), while CRP (AUC = 0.674, 95%CI 0.586-0.761) performed best as a predictor of local complications (AUC = 0.674, 95%CI 0.586-0.761). Regarding admission to the ICU, CRP was the weakest predictor (AUC = 0.741), while PCT performed the best (AUC = 0.833), followed by MBL (AUC = 0.797). Sensitivity and specificity were calculated for the optimal threshold generated by receiver operating characteristic (ROC) curves, rendering sensitivity of 90% and specificity of 87% for PCT in assessing the risk of systemic complications, compared to sensitivity of 83% and specificity of 90% for CRP. MBL showed relatively high sensitivity (96%) but low specificity (25%) for predicting the need for ICU admission. CONCLUSIONS: Early measurement of CRP, PCT, and MBL provides clinicians with important information regarding the course and prognosis of children diagnosed with CAP, thus ensuring prompt, optimal therapeutic management.