Technical specification for clinical diagnosis and treatment of human parvovirus B19 infection in kidney transplant recipients (2022 edition) / 器官移植

Long-term use of immunosuppressant in kidney transplant recipients leads to poor immune function and infection with various pathogens. In recent years, along with the advancement of detection technique of human parvovirus B19 (HPV-B19) infection and the increasing quantity of kidney transplantation, the infection rate of HPV-B19 after kidney transplantation has been elevated year by year, becoming one of the major causes of pure red cell aplasia (PRCA), affecting the recovery of renal allograft function, and even leading to the injury or poor prognosis of renal allograft. To further standardize the diagnosis and treatment of HPV-B19 infection in kidney transplant recipients, Branch of Organ Transplantation of Chinese Medical Association and National Kidney Transplantation Quality Control Center jointly organized experts to formulate the clinical diagnosis and treatment specification for HPV-B19 infection after kidney transplantation from the perspectives of etiology, epidemiological characteristics, clinical manifestations, diagnosis, prevention, treatment, existing problems and prospects of HPV-B19, aiming to provide guidance for standardized prevention and treatment of HPV-B19 infection post-kidney transplantation in China.

Clinical impact & pathogenic mechanisms of human parvovirus B19: A multiorgan disease inflictor incognito

Human parvovirus B19 (B19V) causes myriads of clinical diseases; however, owing to lack of awareness and undetermined clinical impact, it has failed to become a virus pathogen of global concern. Cryptically, B19V causes significant morbidity and mortality. Half of the world population and 60 per cent of Indians are known to be serologically naive and are at risk of acquiring B19V infections. Cumulatively, our data showed 21.3 per cent B19V-infected patients with juvenile chronic arthropathy, recurrent abortions, multi-transfused thalassaemia and leukaemia. In addition, B19V-infected cases that ended fatally included patients with pure red cell aplasia, fulminant hepatitis and haemophagocytic syndrome. Novel clinical associations of B19V observed were amegakaryocytic thrombocytopaenia, myositis and non-occlusive ischaemic gangrene of bowel. B19V possesses multiple receptors which are distributed widely in human tissues. Vascular endothelial cell infection by B19V causes endothelialitis and vasculitic injuries besides antibody-dependent enhancement which empowered B19V to cause multiorgan diseases. Owing to lack of suitable animal model for B19V, true causal role remains to be determined, but numerous reports on B19V infections substantiate a causal role in multiorgan diseases. Hence, B19V infections need to be recognized, investigated and treated besides making efforts on vaccine developments.

Severe Anemia Due to Parvovirus Infection Following Treatment with Rituximab in a Pediatric Kidney Transplant Recipient: Anemia after Treatment of Rituximab in Kidney Recipient Patient

Rituximab (RTX), a monoclonal antibody against the B-cell marker CD20, is commonly used as a treatment for antibody-mediated diseases or B-lymphocyte-mediated diseases. Destruction of B cells may reverse the disease course in many conditions; however, patients who are treated with RTX cannot respond appropriately to de novo infection due to lack of B lymphocytes. Here, we report one such case. A 7-year-old renal allograft recipient presented with severe anemia due to parvovirus infection after RTX treatment. The patient had focal segmental glomerulosclerosis and had received cadaveric kidney transplantation 6 months previously. She was treated with high-dose steroid for acute rejection and RTX for Epstein Barr Virus infection 3 months previously. At presentation, her hemoglobin level was 5.4 g/dL and leukocyte and platelet counts were normal. She had microcytic normochromic anemia and high viral load of parvovirus B19(70,578 copies/mL). Intravenous immunoglobulin (200 mg/kg.d) treatment controlled the progression of anemia and parvovirus infection. De novo parvovirus infection during the B lymphocyte-depletion period may have precipitated the severe anemia in this case. Close monitoring of infection is required after RTX therapy.

Acquired Pure Red Cell Aplasia due to Anti-Erythropoietin Antibodies in a Patient Undergoing Hemodialysis

A 63-year-old man was placed on hemodialysis for the end-stage of renal disease secondary to renal artery stenosis. He was also regularly given epoetin, subcutaneously, for anemia associated with his renal disease. Rapidly progressing erythropoietin (EPO) resistant anemia and reticulocytopenia developed after 1 year of hemodialysis. The patient required frequent red blood cell transfusions. The bone marrow examination demonstrated selective erythroid hypoplasia. A detailed search for the cause of the erythroblastopenia revealed nothing, with the exception of anti-EPO antibodies (Ab). Pure red cell aplasia (PRCA) was suspected due to the anti-EPO Ab. With the immunosuppressive agent and change to the epoetin-therapy, the patient recovered his hemoglobin and reticulocyte counts. Particular attention should be paid for the possibility of PRCA due to anti-EPO Ab in patients undergoing rHuEPO therapy, with an unexplained recombinant human erythropoietin (rHuEPO) resistant anemia, especially via the subcutaneous route.

Thymoma with pure red cell aplasia / 重庆医科大学学报

Objective:To explore the diagnosis and treatment of thymoma with pure red cell aplasia(PRCA).Methods: From May 1999 to March 2006,the cases of thymoma with PRCA were treated.The clinical data was analysed and the Chinese literature was reviewed.Results:The cases of thymoma with PRCA accounted for 4.2%(3/70)of total thymoma treated in the same period,2 cases underwent thymomectomy.No recurrences of thymoma or PRCA was found in 1 case 3 years and 1 case 6 months after operation.There was no effect on 1 case undergoing surgical exploration only.Conclusion: Thymoectomy is the first choice for thymoma with PRCA.The long term effects should be further followed up.