OBJECTIVE:To study the regulatory effect of lentinan (LTN) on immune function in ulcerative colitis (UC) rats and its mechanism. METHODS:64 SD rats were randomly divided into normal group(12 rats)and modeling group(52 rats). UC model was induced in modeling group by a compound method of 2,4-dinitrochlorobenzene(DNCB)acetone and 2,4-DNCB etha-nol. After modeling, rats were randomly divided into model group, positive group (sulfasalazine tablet, 300 mg/kg), LTN low-dose,medium-dose and high-dose groups(0.2,0.4,0.8 mg/kg),with 10 rats in each group. Treatment groups were given rele-vant medicine intragastrically,and normal group and model group were given normal saline intragastrically,once a day,for consec-utive 15 d. The levels of CD3+,CD4+,CD8+in peripheral blood lymphocytes(PBMC)and the levels of TNF-α,IL-2,IL-4 and IL-10 in colon were all determined,and the pathological changes of colon tissue were observed. RESULTS:Compared with normal group,the levels of CD3+,CD4+,CD8+,the ratio of CD4+/CD8+,and the levels of IL-4 and IL-10 decreased significantly,while the levels of TNF-α and IL-2 in colon tissue significantly increased(P<0.05);obvious ulcerative lesion was observed in colon tissue (concentrated in grade Ⅱ and Ⅲ). Compared with model group,the levels of CD3+,CD4+,CD8+,the ratio of CD4+/CD8+,and the levels of IL-4,IL-10 increased significantly,while the levels of TNF-α,IL-2 in colon tissue significantly decreased (P<0.05);the inflammation of colon tissue was significantly reduced,and the ulcer formation was significantly improved. CONCLUSIONS:LTN has a certain improvement effect on UC model rats,and its mechanism may be related to enhancing the immune function.

The etiology of hemophagocytic lymphohistiocytosis (HLH) is complicated and difficult to diagnose, unexplained HLH often with hematological malignancies. Invasive biopsy can help to find etiology, the results may be affected by the technique and the location of the puncture site. Multiangle puncture can improve the success rate, but the corresponding risk increases. A patient with HLH was admitted to Affiliated Hospital of Zunyi Medical College. The etiology was unknown. Active symptomatic support treatment was conducted, at the same time, finding the evidence of viral infection, autoimmune disease related detection, blood culture, bone marrow puncture smear and spleen biopsy were performed respectively to find the pathogen basis. Spleen hemorrhage was not being controlled after spleen biopsy in patients, and emergency splenectomy was adopted to stop bleeding for saving lives. Finally, the patients died of low protein, pulmonary edema and respiratory failure. The bone marrow puncture and spleen biopsy failed to provide the basis for tumor invasion, while the spleen pathological slices plus immunohistochemical indicate diffuse large B cell lymphoma (DLBCL) after splenectomy, which was identified as malignant tumor-associated hemophagocytic syndrome. Underscoring the high risk of bleeding after tumor-associated splenomegaly puncture and the importance of having emergency plans. Through analyzing the clinical characteristics, diagnosis and treatment of this patient, we hope to improve the clinicians' understanding of HLH and lymphoma.