Abstract
Pure red cell aplasia (PRCA) associated with cytomegalovirus (CMV) and Epstein–Barr virus (EBV) infection is uncommon. Here, we describe the clinical features and management of seven cases of Chinese children with PRCA associated with viral infections. The patients presented with pallor on admission. Blood cell counts and marrow smears showed anemia, reticulocytopenia, and aplasia of erythroblasts. Serological investigation and DNA polymerase chain reactions for CMV were positive in four patients and those tests for EBV were positive in other three patients. All patients received blood transfusion, corticosteroids treatment, and ganciclovir injection. Two patients had a complete response and one had a partial response after the treatments. The other three patients had a complete response to second-line therapies, including high-dose methylprednisolone, cyclosporin A, and intravenous immunoglobulin. Only one patient had no response to the therapies. Our results indicated that it might be important to combine immunosuppressive drugs with an antiviral drug in the management of PRCA associated with CMV and EBV infection.
Introduction
Pure red cell aplasia (PRCA) is a rare hematological condition, characterized by normocytic normochromic anemia and reticulocytopenia, and selective aplasia of erythroid cell line in bone marrow, but without changes in either white blood cell or platelet counts.Citation1 PRCA can be a primary hematological disorder in absence of any other associated diseases. However, it may also be secondary to a wide variety of underlying disorders, including thymoma, chronic lymphocytic leukemia, solid tumors, and autoimmune diseases.Citation2–Citation4 Furthermore, PRCA may be associated with viral infections, such as parvovirus B19, cytomegalovirus (CMV), and Epstein–Barr virus (EBV).Citation5
The optimal treatments of PRCA remain uncertain. As clinical and morphological presentations of PRCA are overlapping, management decisions are difficult. A variety of immunomodulatory agents and methods, including corticosteroids, cytotoxic drugs, antithymocyte globulin, intravenous immunoglobulin, and plasmapheresis, have been used to treat this disorder.Citation6–Citation8 Most reported cases of PRCA associated with viral infections are due to parvovirus B19 infection with a compromised immune system.Citation9,Citation10 PRCA associated with CMV and EBV infection is uncommon. Here, we report seven cases of PRCA associated with CMV and EBV infection. Core clinical features and management are described.
Patients and methods
Patients
A total of seven cases of patients were included in our study. All patients were registered in Department of Pediatrics, Sun Yat-sen Memorial Hospital (Guangzhou, China) from January 2003 to December 2010. There were four male and three female children, and their ages ranged from 3 to 36 months. Histories of bleeding, drug intake, and consanguinity were obtained for the patients. Informed content of diagnosis and treatments were obtained from the parents of all the patients.
Laboratory investigations
Diagnosis of PRCA was based on the findings of anemia, reticulocytopenia, and selective erythroid hypoplasia/aplasia in a normocellular marrow with normal myeloid and megakaryocytic cell lines. Thalassemia, glucose-6-phosphate dehydrogenase deficiency, iron deficiency, and Fanconi anemia were excluded. Serological investigation for CMV, EBV, parvovirus B19, hepatitis-A, -B, and -C virus was performed for all the cases. DNA polymerase chain reactions (PCRs) for CMV, EBV, and parvovirus B19 were tested in the patients' blood samples. Liver and kidney function were monitored. Chest X rays or computerized tomography scan were done for the patients.
Treatments
Initially, the patient was managed symptomatically by packed red blood cell transfusion. The first-line therapy was conventional-dose corticosteroids (prednisone at 1 mg/kg/day, tailing when a response occurred). Furthermore, ganciclovir injection (10 mg/kg/day for 7 days, then 5 mg/kg/day for 7 days) was added in the management. When a response was not observed, second-line therapies were used, including high-dose methylprednisolone (20 mg/kg/day for 3 days, then 10 mg/kg/day for 3 days), cyclosporin A (CsA, 8 mg/kg/day, initial serum level 100–300 ng/ml, tailing when a response occurred), intravenous immunoglobulin (IVIG, 1 g/kg/day for 2 days). Complete response was defined as return to normal hemoglobin level (>100 g/l), re-establishment of erythropoiesis (erythroid precusors >10% of marrow nucleated cells), and independence from transfusion. Partial response was as above, but with hemoglobin less than 100 g/l. The patients were followed up in our pediatric hematology clinic after the treatments.
Results
All patients presented with progressive pallor when they were admitted into our hospital. They had no fever, no ecchymoses, and petechiae. General physical examination revealed that the patients had mild-to-severe pallor with no icterus, rash, and lymphadenopathy. No congenital anomalies were found in all the patients. Liver was palpable in four cases (case 1, 2, 4, and 5), with 1–3 cm below the right costal margin. Moreover, these four patients also had splenomegaly, with 1–2 cm below the left costal margin. The other three cases had no hepatosplenomegaly. No history of bleeding, drug intake, and consanguinity was obtained for all the patients. Developmental milestones of the patients were normal.
Complete blood cell counts showed normocytic normochromic anemia in all patients. As shown in , value of hemoglobin and percentage of reticulocytes was (58.9 ± 13.4) g/l and (0.21 ± 0.15)%, respectively. Values of white blood cells and platelet were in normal range. Bone marrow aspirate smears were normocellular with erythroblasts constituting less than 1% of marrow cells. Four cases (case 1, 2, 3, and 4) had CMV immunoglobulin M positive in serological investigation. Value of CMV-DNA load was (2.25 ± 1.33) × 104 copies/ml in peripheral blood in these four cases (normal value <1 × 103 copies/ml). Immunoglobulin M antibodies to EBV capsid antigen were positive in other three cases (case 5, 6, and 7), but antibodies to EBV nuclear antigen and early antigen were negative. Value of EBV-DNA load was (5.55 ± 2.15) × 104 copies/ml in peripheral blood in these three patients (normal value <1 × 103 copies/ml). Furthermore, serological tests for parvovirus B19, hepatitis-A, -B, and -C viruses were all negative in these patients. Liver function showed value of alanine aminotransferase was (85.7 ± 23.5) U/l (normal value <40 U/l). Renal function was normal in all cases. No thymoma was found on chest X rays or computerized tomography scan in all patients.
Table 1. Clinical features and management of PRCA associated with viral infections
First-line therapies with conventional-dose corticosteroids and ganciclovir were given to all the patients. Two patients (case 5 and 7) had a complete response, while one patient (case 1) had a partial response. Increases in hemoglobin were seen within 2–4 weeks of administering corticosteroids. Three patients (case 2, 4, and 6) had high-dose methylprednisolone treatment, case 4 had additional CsA and IVIG treatments, and case 6 had additional CsA treatment. All these three patients had a complete response after the treatments. Corticosteroids were successfully tailed off in these cases. Six months after treatments, serological investigation showed that immunoglobulin M antibodies to CMV and EBV were all negative in the above six cases. Moreover, DNA PCR for CMV and EBV turned to negative (<1 × 103 copies/ml). Remission had been maintained in the above five cases (case 2, 4, 5, 6, and 7) for more than 1 year. Values of liver and kidney function were in normal range. No relapse had been observed. Notably, case 3 with CMV infection had prednisone, CsA, and ganciclovir treatments. No response was found in this patient. The patient had persistent anemia and depended on blood transfusion. Eventually, the patient received umbilical cord blood transplantation but died of pneumorrhagia.
Discussion
In the present study, seven cases were diagnosed with PRCA associated with CMV and EBV infection, without evidences of parvovirus B19 infection. The pathophysiology of PRCA associated with viral infections remains unknown. It has been suggested that in patients with PRCA associated with viral infections, the affected cells are progenitor cells that have been differentiated from hematopoietic stem cells, and the damage is mediated by T-cells.Citation11–Citation13 In infancy, the common causes of PRCA are transient erythroblastopenia of childhood (TEC) and Diamond-Blackfan anemia (DBA).Citation5 TEC, the temporary failure of red cell production, usually spontaneously recovers within a few weeks. As the duration of erythroblastopenia in our patients was 4.72 ± 1.57 months and no recovery occurred in any of the cases, which ruled out TEC. Moreover, the absence of congenital anomalies, normal fetal hemoglobin, and elevated aminotransferases made the diagnosis of DBA highly unlikely.
Ganciclovir, is an antiviral drug that has been reported to be effective in the treatment of CMV and EBV infection.Citation14,Citation15 In the present study, all patients received ganciclovir injection on admission. CMV and EBV were negative 6 months after the treatment. Corticosteroids were the first immunosuppressive drugs used in the treatment of PRCA and so far have been considered the treatment of first choice.Citation16 However, corticosteroids at the conventional doses resulted in a complete response rate of only 28% (2/7) in our study. This result was consistent with the findings of other studies.Citation17,Citation18 Second-line drugs for PRCA included high-dose methylprednisolone, CsA, and IVIG. In our study, three patients had a complete response to the second-line therapies. Only one patient failed to response in the therapies and eventually had allogeneic hematopoietic stem cell transplantation. Recently, other drugs have been applied in the management of PRCA as the second-line therapies, including cyclophosphamide, antithymocyte globulin, alemtuzumab, and rituximab.Citation18 In addition, allogeneic hematopoietic stem cell transplantation is considered for patients with refractory acquired PRCA.Citation19,Citation20 Taken together, five of our patient (5/7) had a complete response to the therapeutic strategies and maintained remission for more than 1 year. Our results indicated that it might be important to combine immunosuppressive drugs with an antiviral drug in the management of PRCA associated with CMV and EBV infection.
Acknowledgement
This work was supported in part by National Natural Science Foundation of China (81100370).
References
- Dessypris EN. The biology of pure red cell aplasia. Semin Hematol. 1991;28:275–84.
- Thompson CA, Steensma DP. Pure red cell aplasia associated with thymoma: clinical insights from a 50-year single-institution experience. Br J Haematol. 2006;135:405–7.
- Hirokawa M, Sawada K, Fujishima N, Kawano F, Kimura A, Watanabe T, et al. Acquired pure red cell aplasia associated with malignant lymphomas: a nationwide cohort study in Japan for the PRCA Collaborative Study Group. Am J Hematol. 2009;84:144–8.
- Atzeni F, Sarzi-Puttini P, Capsoni F, Vulpio L, Carrabba M. Successful treatment of pure red cell aplasia in systemic lupus erythematosus with cyclosporin A. Clin Exp Rheumatol. 2003;21:759–62.
- Vlachos A, Ball S, Dahl N, Alter BP, Sheth S, Ramenghi U, et al. Diagnosing and treating Diamond Blackfan anaemia: results of an international clinical consensus conference. Br J Haematol. 2008;142:859–76.
- Marmont AM. Therapy of pure red cell aplasia. Semin Hematol. 1991;28:285–97.
- Dinçol G, Aktan M, Nalçaci M, Yavuz AS, Keskin H, Dawson B, et al. Clonality of acquired primary pure red cell aplasia: effectiveness of antithymocyte globulin. Leuk Lymphoma. 2001;42:1413–7.
- Choi BG, Yoo WH. Successful treatment of pure red cell aplasia with plasmapheresis in a patient with systemic lupus erythematosus. Yonsei Med J. 2002;43:274–8.
- Brown KE, Young NS. Parvoviruses and bone marrow failure. Stem Cells. 1996;14:151–63.
- Mrzljak A, Kardum-Skelin I, Cvrlje VC, Kanizaj TF, Sustercić D, Gustin D, et al. Parvovirus B 19 (PVB19) induced pure red cell aplasia (PRCA) in immunocompromised patient after liver transplantation. Coll Antropol. 2010;34:271–4.
- Charles RJ, Sabo KM, Kidd PG, Abkowitz JL. The pathophysiology of pure red cell aplasia: implications for therapy. Blood. 1996;87:4831–8.
- al-Awami Y, Sears DA, Carrum G, Udden MM, Alter BP, Conlon CL. Pure red cell aplasia associated with hepatitis C infection. Am J Med Sci. 1997;314:113–7.
- Socinski MA, Ershler WB, Tosato G, Blaese RM. Pure red blood cell aplasia associated with chronic Epstein-Barr virus infection: evidence for T cell-mediated suppression of erythroid colony forming units. J Lab Clin Med. 1984;104:995–1006.
- Togashi J, Sugawara Y, Hashimoto M, Tamura S, Kaneko J, Aoki T, et al. Oral valganciclovir versus intravenous ganciclovir as preemptive treatment for cytomegalovirus infection after living donor liver transplantation: a randomized trial. Biosci Trends. 2011;5:217–22.
- Humar A, Hébert D, Davies HD, Humar A, Stephens D, O'Doherty B, et al. A randomized trial of ganciclovir versus ganciclovir plus immune globulin for prophylaxis against Epstein-Barr virus related posttransplant lymphoproliferative disorder. Transplantation. 2006;81:856–61.
- Sawada K, Hirokawa M, Fujishima N. Diagnosis and management of acquired pure red cell aplasia. Hematol Oncol Clin North Am. 2009;23:249–59.
- Kwong YL, Wong KF, Liang RH, Chu YC, Chan LC, Chan TK. Pure red cell aplasia: clinical features and treatment results in 16 cases. Ann Hematol. 1996;72:137–40.
- Sawada K, Fujishima N, Hirokawa M. Acquired pure red cell aplasia: updated review of treatment. Br J Haematol. 2008;142:505–14.
- Müller BU, Tichelli A, Passweg JR, Nissen C, Wodnar-Filipowicz A, Gratwohl A. Successful treatment of refractory acquired pure red cell aplasia (PRCA) by allogeneic bone marrow transplantation. Bone Marrow Transplant. 1999;23:1205–7.
- Tseng SB, Lin SF, Chang CS, Liu TC, Hsiao HH, Liu YC, et al. Successful treatment of acquired pure red cell aplasia (PRCA) by allogeneic peripheral blood stem cell transplantation. Am J Hematol. 2003;74:273–5.