The occurrence and treatment of hemophagocytic lymphohistiocytosis caused by multiple factors: a case report and literature review.

Hemophagocytic lymphohistiocytosis (HLH) is a high-fatality disease caused by hereditary or acquired immune dysfunction, and is characterized by pathological inflammatory response. Primary HLH (pHLH) has hereditary genetic defects, and secondary HLH (sHLH) is caused by a variety of underlying diseases. Here, we report the case of a patient with aggressive natural killer cell leukemia and HLH-related gene defects who achieved long-term survival after treatment. A 20-year-old man presented to our hospital with symptoms of fever and fatigue. Investigations revealed splenomegaly, cytopenia, hyperferritinemia, hypofibrinogenemia, elevated levels of soluble CD25 (sCD25), and hemophagocytosis in bone marrow. Bone marrow flow cytometry showed 23.4% abnormal natural killer cells, the cells were CD2, CD7, CD16, CD94, NKG2A positive, met the diagnosis of aggressive NK-Cell leukemia. Investigation of the patient's pedigree revealed that mutations of pHLH-related genes (LYST and UNC13D) were inherited from his father and mother, but neither of the parents had the disease. The patient received hematopoietic stem-cell transplantation (HSCT), after which he achieved complete remission. As of 2020-10-19, the patient's survival has exceeded 3 years, and he has returned to his normal life. A variety of factors contribute to the onset of HLH, and this case gives greater insight into the etiology of HLH. Allogeneic HSCT is a key treatment for HLH patients with underlying genetic mutations.

[Clinical characteristics of hemophagocytic syndrome: analysis of 46 cases].

OBJECTIVE: To analyze the clinical manifestations, laboratory findings, treatment and prognosis of patients with hemophagocytic syndrome (HPS). METHODS: A retrospective study was carried out to analyze the underlying disease, clinical characteristics, laboratory findings and outcomes of 46 patients with HPS. RESULTS: This cohort included 19 cases of HPS secondary to cancer, 11 cases of HPS secondary to infection, 10 cases of suspected malignant lymphoma based on PET-CT findings (without biopsy), and 6 cases of unknown etiology. The coincidence rate of the clinical characteristics of the patients with the indices listed in HPS-2004 criteria were: fever (100%), elevated serum ferritin (100%), cytopenias (93.48%), splenomegaly (91.30%), hemophagocytosis in the bone marrow, spleen or lymph nodes (84.78%), hypofibrinogenemia (67.39%), and hypertriglyceridemia (54.05%). The cases of cancer, infections and unknown etiology showed significant differences in serum levels of ferritin and ß2MG (P<0.05), and significant differences were found in triglycerides, LDH, and fibrinogenemia between the nonfatal and fatal cases (P<0.05). CONCLUSION: HPS can be secondary to various underlying diseases, many associated with Epstein-Barr virus infection. Cancer, especially NK/T-cell lymphoma, is the main cause of HPS. Persistent fever, elevated serum ferritin level and cytopenias are the most sensitive indicators for diagnosis of HPS, and early diagnosis and treatment are critical to lower the mortality rate of this disease.

[Comparison of Biological Characteristics and Immunosuppressive Activity between Human Amniotic Mesenchymal Stem Cells and Human Bone Marrow Mesenchymal Stem Cells].

OBJECTIVE: To compare the biological characteristics and immunosuppressive activity between human amniotic mesenchymal stem cells (hAMSC) and human bone marrow mesenchymal stem cells (hBMMSC). METHODS: MSC from human amnion and bone marrow were isolated using enzymatic digestion and Ficoll-Hypaque density gradients, respectively. Their biological characteristics were compared by morphology, cell growth curves, cell cycle profile analysis, immunophenotype and immunofluorescence assay. Their immunosuppressive activities were studied on total activated T-cells with phytohemagglutinin (PHA-PBMSC). An in vitro co-culture was performed to compared the lymphocyte proliferation and the supernatant level of IFN-γ were measured by CCK-8 method and ELISA, respectively. RESULTS: Both hAMSC and hBMMSC demonstrated fibroblast-like morphology. The hAMSC were able to be amplified for at least 15 passages, while the hBMMSC only for 6-7 passages. There was no significant difference in the proportion of G2/M phase cells of the 2 cells types (P>0.05). By FACS analysis for immunophenotype, both MSC were shown to be positive for CD105, CD90, CD73 and negative for CD34, CD45, CD11b, CD19, HLA-DR, but hAMSC were positive for Oct-3/4, which was in contrast to hBMMSC. Both of them expressed vimentin. Both the cells exhibited a inhibitory role on the lymphocyte proliferation induced by PHA in co-culture conditions, that was increased with the increase MSC proportion and both the suppressing effecs were enhanced. The supernatant IFN-γ levels of hAMSC co-cultured with lymphocyte at a ratio of 1:1 after 72 hours were measured by ELISA, and the level of IFN-γ was significantly lower than that in the same co-culture system of hBMMSC. In contrast to the IFN-γ in the PHA-stimulated group, the IFN-γ level in both co-culture groups was significantly lower. CONCLUSION: MSC from amnion displayed a higher proliferative capacity and stem cell properties, compared with hBMMSC. Both MSC can inhibit lymphocyte proliferation and suppress IFN-γ secretion induced by PHA in vitro.