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

Female polysomy-X and systemic lupus erythematosus

OBJECTIVES

Systemic lupus erythematosus (SLE) occurs more commonly in females than in males. Recent evidence suggests that genetic factors transmitted by the X-chromosome may confer increased risk for autoimmune disease in general, and for SLE in particular. It is therefore possible that X-chromosome polysomy might confer further increased risk for lupus. In addition to describing the clinical and immunologic features of a young woman with polysomy-X and SLE, we sought to review all other published cases associating female or male polysomy-X with SLE or other forms of autoimmunity.

METHODS

We report a case of a prepubertal girl with polysomy-X and SLE. We performed a systemic literature review for cases of polysomy-X and SLE and summarize previously published cases. In addition, we reviewed reports concerning the possible association between SLE and other connective tissue diseases and male polysomy-X.

RESULTS

An 11-year-old girl with tetrasomy-X (48 XXXX karyotype) presented with prolonged fever. Workup led to the diagnosis of SLE, and subsequent renal biopsy revealed mild diffuse mesangial proliferative glomerulonephritis. Two additional cases of SLE in women with 47 XXX and one of 48 XXXX karyotype were found in a literature review and compared to the present case. We identified studies that found X-chromosome polysomy to be over-represented in male patients with SLE and case descriptions of connective tissue diseases occurring in patients with polysomy-X.

CONCLUSION

No consistent pattern of disease was observed in female polysomy patients with SLE. Taken together with the data concerning the frequency of polysomy-X among males with SLE, our findings provide additional support for the hypothesis that X-chromosome polysomy may confer increased susceptibility to SLE. Molecular mechanisms that might account for this phenomenon are discussed.

Autoimmune hemolytic anemia accompanied by reactivation of an Epstein-Barr virus infection with suppressed CTL response to EBV-infected cells in an elderly man

An 88-year-old man with autoimmune hemolytic anemia (AIHA) who had been treated with low dose prednisolone developed a sudden worsening of his anemia accompanied by reactivation of Epstein-Barr virus (EBV). We established EBV-infected spontaneous lymphoblastoid cell lines (LCL), performed an enzyme-linked immunosorbent spot assay, and confirmed a significantly suppressed EBV-specific cytotoxic T-cell (CTL) response to the LCL. EBV reactivation might have been brought about by suppressed CTL activity which could have been due to low dose PSL administration or aging. Since the EBV-DNA titer decreased as AIHA improved, we concluded that EBV might have played a role in the development of anemia.

Persistent anemia in a patient with diffuse large B cell lymphoma: pure red cell aplasia associated with latent Epstein-Barr virus infection in bone marrow

We report a case of pure red cell aplasia (PRCA), which was initially suspected as a result of bone marrow involvement of diffuse large B cell lymphoma. Persistent anemia without an obvious cause was observed in a 47-yr-old man diagnosed with relapsed diffuse large B cell lymphoma. The bone marrow study showed only erythroid hypoplasia without the evidence of bone marrow involvement with lymphoma cells, thus PRCA was suggested. However, parvovirus infection was excluded as a potential cause of PRCA because of negative IgM anti-parvovirus B19 antibody and negative parvovirus PCR in the serum. Latent Epstein-Barr virus (EBV) infection of bone marrow was suggested by in situ hybridization with EBV-encoded small RNA (EBER) that showed a strong positive expression in bone marrow cells. Thus, PRCA was thought to be associated with latent EBV infection in bone marrow cells. Although the finding of unexplained anemia is a possible predictor of bone marrow involvement with lymphoma cells, PRCA as a result of a viral infection including EBV should be considered in lymphoma patients. This is the first report of the occurrence of PRCA associated with latent EBV infection in a patient with non-Hodgkin's lymphoma.

[A case of systemic lupus erythematosus accompanied with pure red cell aplasia]

Pure red cell aplasia (PRCA) is a rare cause of anemia associated with SLE. We herein report a case presenting with SLE and PRCA. A 33-year-old woman, who had been suffering from photosensitivity, proteinuria, and pancytopenia, was diagnosed to have SLE. She showed normochromatic normocytic anemia. The serum level of haptoglobin was <10 mg/dl, and Direct Coombs' test was negative. Her reticulocyte count was 0.8%. Her clinical and laboratory features, except for anemia, had recovered in response to 50 mg/day of prednisolone. The serum level of haptoglobin had normalized, but the reticulocyte count remained low. The bone marrow findings revealed erythroid hypoplasia, and she was diagnosed to have PRCA complicated with SLE. No viral DNA of human parvovirus B19 in her bone marrow was detected. The anemia gradually improved following the further use of 50 mg/day prednisolone. In order to disclose the mechanism of PRCA in this patient, we examined the effects of her peripheral T lymphocytes on erythrogenesis, using erythroid colony-forming cells (ECFC) in her peripheral blood. When we co-cultured peripheral T cells and ECFC, her T cells inhibited erythroid colony formation in a dose dependent manner. Several reports have shown the presence of inhibitory factors in SLE patients' serum such as antibodies against erythroid progenitors or erythropoietin, while other reports have shown abnormal T cells that inhibit the growth of erythroid progenitors. Our study suggests that these inhibitory T cells may therefore have played an important role in the pathogenesis of this patient.

Infection of autoreactive B lymphocytes with EBV, causing chronic autoimmune diseases

I hypothesize that human chronic autoimmune diseases are based on infection of autoreactive B lymphocytes by Epstein-Barr virus (EBV), in the following proposed scenario. During primary infection, autoreactive B cells are infected by EBV, proliferate and become latently infected memory B cells, which are resistant to the apoptosis that occurs during normal B-cell homeostasis because they express virus-encoded anti-apoptotic molecules. Genetic susceptibility to the effects of B-cell infection by EBV leads to an increased number of latently infected autoreactive memory B cells, which lodge in organs where their target antigen is expressed, and act there as antigen-presenting cells. When CD4(+) T cells that recognize antigens within the target organ are activated in lymphoid organs by cross-reactivity with infectious agents, they migrate to the target organ but fail to undergo activation-induced apoptosis because they receive a co-stimulatory survival signal from the infected B cells. The autoreactive T cells proliferate and produce cytokines, which recruit other inflammatory cells, with resultant target organ damage and chronic autoimmune disease.