Brucellosis-Associated Hemophagocytic Lymphohistiocytosis: Case Report and Literature Review

Shuwen Jiang¹霞 Xia²Hongyu Wu¹Peng Zhang¹Xiaohua Li¹Kaiyu Zhang^1*

• ¹Department of Infectious Diseases and Center of Infectious Diseases and Pathogen Biology, The First Hospital of Jilin University, Changchun, China
• ²Department of Gastroenterology, Lequn Branch, The First Hospital of Jilin University., Changchun, China., China

Introduction: Hemophagocytic Lymphohistiocytosis (HLH), a rare and deadly disease, is often categorized as primary (familial) or secondary (acquired) depending on the etiology and underlying cause. Secondary HLH often develops in the presence of infectious, malignant, rheumatologic, or metabolic conditions, with infections, especially Epstein-Barr Virus (EBV) infection, among the leading causes. Others include Brucella infection-induced HLH, although it is relatively rare, with only eight cases reported in the past decade, all showing a favorable prognosis following timely diagnosis and treatment. Case description: A 53-year-old adult male with brucellosis who developed secondary HLH and multiple organ dysfunction, presented to our hospital with a two-month history of fever and abnormal liver enzymes.Initial blood culture following admission confirmed the Brucella spp. in the aerobic bottle after ⁓87.85 h of incubation. However, after the initial discharge, the patient did not adhere to the prescribed antibiotic therapy and thus showed symptoms of fever and abdominal discomfort, and was subsequently readmitted to our hospital. Laboratory examination also revealed pancytopenia. An additional blood culture further revealed the growth of Brucella spp. in the aerobic bottle after ⁓113.67 h of incubation. Other findings included decreased fibrinogen, increased ferritin, increased soluble IL-2 receptor α chain (sCD25), decreased Natural Killer (NK) cell activity, presence of hemophagocytic cells in the bone marrow smear, splenomegaly, and abnormal liver and kidney functions. The HScore score was 230 points. A thorough assessment was made, which lead to the exclusion of other possible diseases, culminating the identification of Brucella infection as the most probable cause of HLH. Consequently, the patient was given antiinfection (doxycycline, levofloxacin, etimicin, rifampin), glucocorticoids (GCs), Human Immunoglobulin (HIG), and other symptomatic supportive treatments, which ultimately improved his condition. Conclusion: Despite the generally poor prognosis of HLH patients, those with Brucellainduced HLH may have a favorable outcome with prompt intervention. Conversely, a delayed treatment could increase the risk of HLH onset and progression, leading to death in severe cases.