Pure red cell aplasia in childhood and adolescence: pathogenesis and approaches to diagnosis

Pure red cell aplasia in a patient with trisomy X chromosome abnormality and reactivated Epstein-Barr virus infection

We describe a woman with a congenital chromosome anomaly, 47,XXX, who developed chronic pure red cell aplasia (PRCA). The patient had serologic reactivity consistent with that of reactivated Epstein-Barr virus (EBV) infection, as judged by high titers for anti-EBV viral capsid antigen (VCA) immunoglobulin G (IgG) and anti-early antigen (EA) IgG. Detection of EBV genome in peripheral blood cells and cell-free serum also supported the diagnosis. Although EBV infection has been implicated in the pathogenesis of acute PRCA, the viral infection rarely results in a chronic disease state. So far, only 1 case of EBV-associated chronic PRCA has been reported, to the best of our knowledge. Chronic PRCA also is known to occur on an autoimmune basis. Individuals carrying an extra X chromosome, such as XXY and XXX, are prone to development of immune abnormalities. Our patient had an anti-DNA autoantibody and a positive result of the direct Coombs test. The pathogenesis of PRCA in this case seemed to involve multiple factors. In addition to the infectious agent, host factors may have played a role. Although the etiologic link between chronic PRCA and trisomy X remains to be elucidated, our findings suggest the importance of karyotype analysis as well as search for infectious agents in patients with chronic PRCA.

Transient erythroblastopenia of childhood: prospective study of 10 patients with special reference to viral infections

PURPOSE

It has been proposed that human parvovirus B19 or human herpesvirus 6 (HHV-6) causes transient erythroblastopenia of childhood (TEC). This study was performed prospectively and accurately in a sufficiently large population to confirm or reject these suggestions, or possibly to find another causative agent for TEC.

PATIENTS AND METHODS

The authors studied prospectively the causative aspects of 10 consecutive children with TEC presenting at five Swedish pediatric clinics from 1994 to 1998 using serologic assays and polymerase chain reaction assays for B19, HHV-6, cytomegalovirus, and Epstein-Barr virus (EBV). The authors also performed isolation investigations of virus from bone marrow, stools, and aspirate from the nasopharynx.

RESULTS

The authors found acute EBV infection in one child. There were no other instances of IgM positivity for any viruses at presentation, but a few children did show IgG positivity to HHV-6 (n = 2), EBV (n = 1), and cytomegalovirus (n = 1). No children were positive with respect to IgG for B19. However, it could not be determined when these children had been infected, and thus, a connection to TEC cannot be proved or excluded. No child showed B19 or HHV-6 DNA in serum or bone marrow collected at presentation. Isolation of virus from bone marrow, stools, and aspirate from nasopharynx culture was negative in all children but one, who had rotavirus in stool.

CONCLUSIONS

HHV-6, B19, EBV, and cytomegalovirus are not common causative agents of TEC. The authors found no proof of any single agent causing TEC.

Anti-CD20 monoclonal antibody for the treatment of severe, immune-mediated, pure red cell aplasia and hemolytic anemia

Immune-mediated, acquired pure red cell aplasia (PRCA) is a rare disorder frequently associated with other autoimmune phenomena. Conventional immunosuppressive treatment is often unsatisfactory. Rituximab is a monoclonal antibody against the CD20 antigen, highly effective for in vivo B-cell depletion. An 18-month-old girl with both severe PRCA and autoimmune hemolytic anemia, refractory to immunosuppressive treatment, received 2 doses of rituximab, 375 mg/m(2) per week. The drug was well tolerated. After anti-CD20 therapy, substitutive treatment with intravenous immunoglobulin was started. The treatment resulted in marked depletion of B cells; a striking rise in reticulocyte count ensued, with increasing hemoglobin levels, finally leading to transfusion independence. The child is now 5 months off-therapy, with normal hemoglobin and reticulocyte levels. This case suggests a role of anti-CD20 monoclonal antibody for treatment of patients with antibody-mediated hematologic disorders. (Blood. 2001;97:3995-3997)

Lamivudine-induced pure red cell aplasia

The aim of this report is to describe five patients with lamivudine-induced pure red cell aplasia, an association not previously described. We describe patients with unresponsive anemia in whom a complete study including blood cell counts, reticulocyte counts, hemolysis tests, and bone marrow aspiration was performed. Pure red cell aplasia was considered when anemia was associated with normal leukocyte and platelet counts with a corrected reticulocyte count below 1% and less than 5% bone marrow erythroid progenitors in the absence of positive hemolysis tests. Complete remission was considered when bone marrow erythroid progenitors were at least 16%. Five male patients had pure red cell aplasia with a median age of 32 years (range 29 to 37 years). Before lamivudine, they had hemoglobin >11.8 g/dl without transfusion requirements. After receiving the drug, hemoglobin dropped to 5.2 g/dl (4.3 to 6.1 g/dl) with high transfusion requirements and mean bone marrow erythroid progenitors of 1.84% (0 to 4%). Withdrawal of lamivudine was attempted to confirm the diagnosis. Seven weeks after stopping lamivudine, hemoglobin rose up to 12.8 g/dl (11 .3 to 13.8 g/dl) and bone marrow erythroid progenitors increased up to 25.6% (21 to 40%) without transfusion requirements. Lamivudine-induced pure red cell aplasia may be a cause of anemia unresponsive to conventional treatment in AIDS. Since lamivudine use in Mexico has been relatively short, we expect more cases to appear in the future.

Diamond-Blackfan anaemia

Diamond-Blackfan anaemia (DBA) has had an intellectual allure for decades for clinical and experimental haematologists. The syndrome has a haematological phenotype of early-onset red-cell aplasia but is coupled with a baffling array of pleiotropy. There is discordance with modes of inheritance, physical anomalies, erythropoietic response to corticosteroid therapy, spontaneous 'remissions', and evolution to malignant myeloid transformation and to cancer. The recent discovery of two genes associated with DBA is the entry point for explaining the diversity of the phenotype and for understanding the molecular basis of the syndrome.

Isoniazid-induced pure red cell aplasia in two siblings

Pure red cell aplasia (PRCA) is a rare complication of treatment with isoniazid mainly observed in adults. We report two siblings who had anemia caused by PRCA during administration of isoniazid. On discontinuation of isoniazid, the anemia resolved rapidly. PRCA should be considered as a possible cause of unexplained anemia during isoniazid therapy in children.

Clinical value of bone marrow cultures in childhood pure red cell aplasia

PURPOSE

We assessed the value of marrow cultures for defining the pathophysiology, diagnosis, and therapeutic response to immunosuppressive therapy in childhood pure red cell aplasia (PRCA).

PATIENTS AND METHODS

Patients were evaluated either at diagnosis (n = 23) or at the time of treatment failure (n = 2). Twelve patients had transient erythroblastopenia of childhood (TEC), 4 had Diamont-Blackfan anemia (DBA), and 9 had acquired sustained PRCA (A-Su-PRCA). Bone marrow mononuclear cells were cultured with combination of human recombinant (rhu) erythropoietin (EPO), granulocyte monocyte colony stimulating factor (GM-CSF), granulocyte colony stimulating factor (G-CSF), Interleukin 3 (IL-3), either with or without stem cell factor (SCF), and burst forming unit of erythroid (BFU-E) growth was assessed.

RESULTS

The combination of growth factors without SCF failed to induce any erythropoiesis (BFU-E < 10/10(5) mononuclear cells) in 10 patients (2 with TEC, 2 with DBA, and 6 with A-Su-PRCA), although the growth of erythroid colonies was substantially lower in the remaining patients than in controls (45.5 +/- 15.4 versus 91.7 +/- 12.7, p < 0.05). Addition of SCF restored erythropoiesis in all but 6 patients (5 with A-Su-PRCA and 1 with DBA). Five of 6 nonresponders did not respond to any immunomodulating therapy; of the 5, 3 had or developed some evidence of myelodysplasia.

CONCLUSION

Our data indicate that in vitro colony studies might prove to be a useful diagnostic tool, because erythropoiesis' poor response to growth factors, including SCF, may suggest the diagnosis of myelodysplasia. Moreover, it may have predictive value; in cases of PRCA, regardless of etiology, poor growth of erythropoietic colonies may predict refractoriness to immunomodulating therapy.

Acquired pure red cell aplasia in Japan

We reviewed the clinical features of 150 patients with acquired pure red cell aplasia (PRCA) in Japan. There were 35 patients with acute type and 115 with chronic type PRCA. Of the acute PRCA patients, 17 had human parvovirus B19 infection. Drug-induced PRCA was demonstrated in 7 patients. Of the 115 patients with chronic PRCA, 51 patients were classified as primary and 64 cases were associated with miscellaneous diseases such as thymoma, a variety of hematological disorders and collagen diseases. Among the hematological disorders, PRCA was most frequently seen in granular lymphocyte proliferative disorders (GLPD). The erythroid colony growth patterns from bone marrow were variable. The serum erythropoietin level was high in most patients. Various kinds of treatment were tried for the chronic PRCA cases. Cyclosporin A (CyA) was the most effective form of treatment and the response rate was 82% (31/38). Twenty-three of 37 patients (62%) responded to bolus methylprednisolone therapy. The largest number of patients were treated with oral prednisolone, and the therapy was effective in 27 of the 55 (49%). The response rate to cyclophosphamide was only 29% (5/17), but in combination with prednisolone, half of the patients (7/14) responded to the therapy. CyA is recommended as the first-line therapy for acquired chronic PRCA.

Pure red cell aplasia during carbamazepine monotherapy

A 7-year-old girl developed pure red cell aplasia during carbamazepine (CBZ) monotherapy for epilepsy. She developed generalized clonic convulsions at the age of 7 years and 8 months. Treatment with CBZ was begun. Two months later she was admitted to our hospital because of severe anemia. Bone marrow examination revealed the almost complete absence of erythroblasts, with normal myelopoiesis and megakaryocytopoiesis, indicating pure red cell aplasia. Following the discontinuation of CBZ, she developed brisk reticulocytosis within 1 week and her hemoglobin level rose to a normal one within 1 month. Although the hematological toxicity of CBZ is well documented, isolated cessation of red cell production is uncommon. A patient who is undergoing treatment with CBZ should be carefully monitored, especially for serious adverse reactions including pure red cell aplasia.

Congenital Marrow Failure Syndromes and Malignant Hematopoietic Transformation

In the current era of advanced supportive care and administration of recombinant cytokines and other effective therapies, patients with congenital (inherited) marrow failure syndromes usually survive the early years of life and beyond. With the extended lifespan, a new “natural history” for these syndromes is evident. Although these disorders were always classified as “benign” historically, it is now evident that most of these conditions confer an inordinately high predisposition to myelodysplastic syndromes and acute myelogenous leukemia (MDS/AML). Since carcinogenesis occurs as a sequence of events that is driven by genetic damage and by epigenetic changes, the hypothesis is advanced that the first “hit” or leukemia-initiating step is the constitutional genetic mutation, itself, that initially manifests as a single lineage or multiple lineage marrow failure. The leukemic promotion and progression steps leading to MDS/AML can then ensue readily in the initiated pool of progenitors or stem cells. Thus, the distinction between benign and malignant hematology in the context of the inherited marrow failure disorders has become blurred and new definitions for these syndromes should be developed.

A case of pure red cell aplasia: follow-up on different immunosuppressive regimens

A 66-year-old patient was admitted to our hospital in January 1992 for further evaluation of severe normocytic anemia. Hemoglobin (Hb) was 3.5 g/dl, reticulocyte count 1%. Bone marrow showed a nearly complete lack of red cell precursors, thus favoring the diagnosis of acquired pure red cell aplasia (PRCA). Immunosuppressive therapy with prednisolone was started but had to be supplemented with azathioprine because of a further rapid decrease in Hb to 3.7 g/dl after an initial transfusion of 6 U red blood cells. However, with this regimen a renewed decrease in Hb to 6.6 g/dl was noted, and further transfusions were required. Therefore therapy was switched to cyclosporine A (CyA) while tapering off prednisolone. Four months after the initial diagnosis a positive parvovirus B19 IgM antibody was found. After the failure of hematological remission with three immunosuppressive regimens a course of high-dose intravenous immunoglobulins (IVIG) was administered in July 1992. Six weeks after IVIG therapy a peak hemoglobin concentration of 12.3 g/dl was noted, and further transfusion was not required. CyA was tapered off in October 1992. One month later CyA was reinstituted because of a relapse of PRCA but was unsuccessful until January 1993. At this time immunosuppressive CyA therapy was discontinued because of a periodontal abscess. In February 1993 a second IVIG infusion was given, and a second remission of PRCA was noted, showing an increase in hemoglobin up to 14.5 g/dl by November 1993. At the last follow-up visit in February 1994 our patient was still in complete hematological remission.

Sustained remission of immune-mediated red cell aplasia in a child after intravenous administration of gamma globulin

A 4-year-old white boy with immune-mediated red cell aplasia and severe anemia was given high intravenous doses of gamma-globulin. The therapy was well tolerated and followed by complete resolution of the inhibition of erythropoiesis with no recurrence of disease. Eight months after discontinuation of treatment, the patient has a normal complete blood cell count.