Clinical and laboratory characteristics of severe fever with thrombocytopenia syndrome in Chinese patients

Abstract

Severe fever with thrombocytopenia syndrome (SFTS) associated with severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging infectious disease. 12 patients with severe fever with thrombocytopenia syndrome in our study were presented mainly with fever and severe malaise. The clinical manifestations typically became worse on the 6th or 7th day. The average fever time is 9.11 ± 1.54 days. Most of them had multiorgan dysfunction, and part of them had hemophagocytic lymphohistiocytosis histiocytosis (HLH). The characteristic laboratory findings in the early stage were the drop of white blood cells (WBC), platelets (PLT) and serum Ca++, while increase of aspartate amino transferase (AST), creatine kinase (CK), and lactate dehydrogenase (LDH). CD3+CD4+ were significantly decreased, while CD3-CD56+ were significantly increased, whereas CD3+CD8+ were constantly elevated throughout the disease course. Ten to 14 days after illness onset, symptoms were improved, accompanied by resolution of laboratory abnormalities. These results indicate that severe fever with thrombocytopenia syndrome has an acute onset and self-limited course. It is a systemic infection. The host immune response caused tissues and organs injury. The improvement of symptoms and laboratory tests is consistent with the elimination of the virus and recover of immune response. Further investigation should be done in order to better understand this disease and guide the clinical treatment.

Circulating regulatory T cells in patients with severe fever with thrombocytopenia syndrome

“…Reports have shown that subpopulations of T cells were found to be changed at different phases of SFTSV-infected patients [16,19]. The present study revealed that CD4  CD25 Foxp3  cells were up-regulated in the circulating blood of patients with SFTS, and the percentage of CD4  CD25 Foxp3  cells negatively correlated with the leukocyte counts in patients with SFTS.…”

“…The correlation analyses showed that the proportion of CD4/total lymphocytes was positively correlated with lymphocyte counts. Previous studies found that total CD3  CD4 cells were significantly decreased in SFTSV-infected patients, especially during acute phase infection and in severe cases [16]. Thymusderived (T) lymphocytes play an important role in cellular immunity.…”

Sensitive and Specific PCR Systems for Detection of Both Chinese and Japanese Severe Fever with Thrombocytopenia Syndrome Virus Strains and Prediction of Patient Survival Based on Viral Load

“…The small number of cases may be a reason for the results reported by Gai et al (10) that did not find any significant relationship between these two factors. Since several other significant prognostic indicators (e.g., cytokine levels, chemokine levels, platelet counts, lactate dehydrogenase [LDH] levels, and aspartate transaminase [AST] levels) have already been reported (9,10,16,17), the combined use of the viral RNA level with these indicators may provide more substantial information that can be used to select the therapeutic strategy and predict patient prognosis.…”

“…It was previously reported that some patients exhibit neurological symptoms (1,3,4,17). However, we tested cerebrospinal fluid samples from only two patients, so further studies are needed to determine whether the nervous tissue is a major site of virus multiplication.…”

Bone marrow findings in severe fever with thrombocytopenia syndrome: prominent haemophagocytosis and its implication in haemophagocytic lymphohistiocytosis

“…Chen et al 11 described one patient with proliferation of nucleated cells and megakaryocytes on bone marrow cytology. Weng et al 12 reported nine cases with histiocytes and phagocytes observed on bone marrow examination; however, no detailed descriptions were provided, so it is not clear if the results were haemophagocytosis.…”