Parvovirus B19-induced anemia in renal transplantation: a role for rHuEPO in resistance to classical treatment

Human parvovirus B19 (PVB 19) is responsible for pure red cell aplasia in immunocompromised patients, and particularly solid organ recipients. Intravenous immunoglobulins (IVIG) have been shown to be efficient to achieve the correction of anemia in association with the reduction of immunosuppression. We report a case of kidney transplant recipient with PVB 19-induced anemia that did not respond to recombinant human erythropoietin (rHuEPO) and to a first course of IVIG. After discontinuation of rHuEPO, a second course of IVIG was successful with the resolution of anemia. We discuss the role of rHuEPO that may facilitate PVB 19 replication in erythropoietin-sensitive human erythroid progenitor cells.

Postmortem diagnosis of Diamond-Blackfan anemia

Diamond-Blackfan anemia (DBA) is a rare etiology for congenital anemia, but this diagnosis should be considered when aregenerative hypoplastic anemia occurs in infancy. A term infant girl received a red blood cell transfusion at birth for neonatal anemia (hemoglobin 75 g/L) initially attributed to abruptio placentae. There were no additional investigations. Hemoglobin gradually decreased during the first 4 weeks of life, leading to severe anemia and death despite transfusions. A postmortem diagnosis of DBA was made by extraction of DNA collected on blood filter paper showing a deletion in RPS19 gene. Neonatal anemias should be carefully investigated and close follow-up should be performed during the first months of life, even if there is an obvious hemorrhagic etiology.

Therapy-related myelodysplasia and/or acute myeloid leukaemia after autologous haematopoietic progenitor cell transplantation in a prospective single centre cohort of 221 patients

To evaluate the incidence and the predictive signs of therapy-related myelodysplasia and/or acute myeloid leukaemia (tMDS/tAML), we undertook a prospective study over a 4-year period of 221 patients who underwent autologous haematopoietic progenitor cell transplantation. Only seven patients (3.1%) were identified to have tMDS/tAML. Peripheral cytopenia was the first sign; diagnosis could be achieved by cytological analysis of bone marrow smears using World Health Organization criteria. All patients presented with bi- or trilineage dysplasia. Haematopoietic reconstitution was significantly delayed in patients progressing to tMDS/tAML compared with the control group. Typical cytogenetic abnormalities were observed in five of seven patients. The mean time interval between transplantation and cytological diagnosis, or detection of cytogenetic abnormalities, was 20.0 months and 31.2 months respectively. Pantelomeric fluorescence analysis using quantitative fluorescence in situ hybridization enabled us to make two major observations: (i) the fluorescence intensity in metaphases of all autografted patients was weak, and highly variable between tMDS patients; (ii) a drastic reduction of the telomere fluorescence intensity was observed in two patients who rapidly evolved to acute leukaemia. In conclusion, early detection of tMDS/tAML could be achieved by close follow-up of the bone marrow repopulation, and confirmed by cytological bone marrow examination and cytogenetic study. Our results address the implication of several factors, such as the initial telomeric status, and the effect of cytogenetic abnormalities and clonal expansion on bone marrow repopulation.

Heavy transfusions and presence of an anti-protein 4.2 antibody in 4. 2(-) hereditary spherocytosis (949delG)

BACKGROUND AND OBJECTIVE

A patient with hereditary spherocytosis (HS) was found not to have red cell membrane protein 4.2. This rare form of HS, or 4.2 (-) HS, stems from mutations within the ELB42 or the EPB3 genes. The patient had long suffered from a gastric ulcer and impaired liver function. He had had several dramatic episodes of gastrointestinal tract bleeding and had received numerous transfusions. An antibody against a high frequency, undefined antigen was found, creating a transfusional deadlock. We elucidated the responsible mutation and searched for an anti-protein 4.2 antibody.

DESIGN AND METHODS

Red cell membranes were analyzed by SDS-PAGE and by Western blotting. Nucleotide sequencing was performed after reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR.

RESULTS

The not previously described mutation was a single base deletion: 949delG (CGCAECC, exon 7, codon 317) in the homozygous state. It was called protein 4.2 Nancy. The deletion placed a non-sense codon shortly downstream so that no viable polypeptide could be synthesized. The patient carried a strong antibody against protein 4.2 as shown by Western blotting.

INTERPRETATION AND CONCLUSIONS

The manifestations resulting from the mutation described were compared with the picture of HS stemming from other ELB42 gene mutations. We discuss the mechanism through which the anti-protein 4.2 antibody developed. There was no way to establish or to rule out whether the antibody participated in the transfusional deadlock found in our patient.

Has the prognosis of adult patients with acute myeloid leukemia improved over years? A single institution experience of 784 consecutive patients over a 16-year period

We reviewed the reports of 784 consecutive patients admitted to our department for newly diagnosed acute myeloid leukemia (AML) over a 16-year period. Median, 5-year and 10-year overall survivals were 9. 5 months, 17.3% and 11.7% respectively. Induction treatment (698 patients) resulted in 50% complete remissions (CR) (from 26.5% in secondary AML to 81.2% in patients <60 years with de novo AML). Period of diagnosis (1980-84/85-89/90-95) demonstrated a major significance for CR achievement and OS in multivariate analysis. In patients >/=60 years (372), CR rate increased (25% to 36.8%, P = 0. 03), and 5-year OS (3.7% to 10.6%, P = 0.022) improved, probably due to an increase in the proportion of patients administered conventional combined chemotherapy (54.5% to 83.8%, P < 0.0001). In younger patients CR rate continuously increased (61.5% to 74.8%, P = 0.028) with an associated improvement of 5-year OS (19.2% to 35.4%). No significant change in DFS and CR durations was observed. This large single center study on a large cohort of unselected AML patients reflects the improvement achieved in the management of AML patients, likely due to improvement of supportive care practices, administration of conventional induction to more elderly patients, and intensification of induction and post-remission treatments in patients <60 years.

Suppression of CDA II expression in a homozygote

The CDAN2 gene, responsible for congenital dyserythropoietic anaemia, type II (CDA II), was recently mapped to 20q11.2. We report data on an additional member of a previously studied CDA II family. This member had always been regarded as haematologically normal. Unexpectedly, she had the same microsatellite assortments around the CDAN2 alleles as her three sisters with CDA II. In particular, she was a homozygote for microsatellites D20S863 and D20S841. This prompted an analysis of all facets of her phenotype. The Ham test was negative. The bone marrow smears contained a normal proportion of binucleate erythroblasts. Electron microscopy revealed the absence of extensive stretches of cisternae beneath and parallel to the inner surface of the erythroblast plasma membrane. Proteins of the endoplasmic reticulum, which contaminate the reticulocyte plasma membrane in CDA II patients, were missing. Only the shape of the band 3 peak appeared slightly altered. This case exemplifies that homozygosity (or compound heterozygosity) for a deleterious gene may be silenced, or almost completely silenced. In recessively inherited diseases, suppressed phenotypes tend to be overlooked in siblings where both patients and unaffected individuals are expected.

Simultaneous activity of MRP1 and Pgp is correlated with in vitro resistance to daunorubicin and with in vivo resistance in adult acute myeloid leukemia

In adult acute myeloid leukemia (AML), the weight of the contribution of the combined activity of Pgp and MRP1 to drug resistance is not known. To address this question, we compared the activity of these proteins to the in vitro resistance to daunorubicin (DNR), etoposide, and cytosine arabinoside (Ara-C), using the calcein-AM uptake and the 3-[4, 5-di-methyl-thiazol-2, 5-diphenyl] tetrazolium bromide (MTT) assay in 80 adult AML patients. We found no correlation or only a weak correlation between the in vitro drug resistance to DNR and etoposide and MRP1 or Pgp expression or function when tested separately. However, a strong correlation was observed between the simultaneous activity of MRP1 and Pgp (quantified as the modulation of calcein-AM uptake by cyclosporin A and probenecid) and the LC50 of DNR (r =.77, P <.0001). This emphasized the role of these two proteins, not separately, but together in the resistance to DNR. In contrast, Mvp/LRP expression did not correlate with the LC50 of DNR. A high level of simultaneous activity of Pgp and MRP1 was predictive of a poor treatment outcome (for achievement of CR [P =.008], duration of relapse-free survival [RFS; P =.01], and duration of overall survival [OS; P =.02]). In addition, high LC50 of DNR and high LC50 of etoposide together were also predictive of a poor treatment outcome (for duration of RFS [P =.02] and duration of OS [P =.02]). The unfavorable cytogenetic category was more closely associated with the combined activity of both MRP1 and Pgp (P =.002) than with the activity of Pgp or MRP1 separately. This could explain the poor prognosis and the in vitro resistance to daunorubicin in this group of patients. These data suggest that treatment outcome may be improved when cellular DNR and etoposide resistance can be circumvented or modulated. Modulation of not only Pgp but also MRP1 could be essential to attain this aim in adult AML.