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 hepatitis. The initial blood culture upon admission revealed the presence of Brucella spp. in the aerobic bottle after ⁓87.85 h of incubation. However, due to fever and abdominal discomfort, the patient was not given antibiotics until he was 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. After excluding other possible diseases, Brucella infection was identified as the most probable cause of HLH. Consequently, the patient was administered antibiotics, Glucocorticoids (GCs), and Human Immunoglobulin (HIG) for HLH, along with other symptomatic supportive treatments, ultimately improving his condition. Conclusion: Despite the generally poor prognosis of HLH patients, those with Brucella-induced HLH may have a favorable outcome with prompt intervention. Conversely, a delayed intervention could increase the risk of HLH onset and progression, leading to death in severe cases.