Hematopoiesis: The forming of new blood cells.
Refractory: Not responding to treatment.
Precursors: A substance that precedes another substance.
Stem Cell: Cell from which platelets, red blood cells, and white cells grow in the bone marrow.
Summary of other DBA research:

In this section we will provide up-to-date and post-publication/public information on DBA and its treatment. The studies that are neither made public nor published in biomedical journals will not be discussed. This section will be updated quarterly or whenever a significant change takes place (termination of ongoing trials or opening of new ones). The synopses provided in this section are for informational purposes only. We believe that participation in well designed and executed research studies is important in understanding the pathology and treatment of rare diseases such as DBA. However, the listing of a study should not be considered as an endorsement by the Diamond Blackfan Anemia Registry. Please contact your physician if you are considering enrollment in any of these studies.

Biological Studies:
Approximately 1% of the circulating red blood cells are lost daily or under certain conditions that require an increase in red blood cell mass (e.g. bleeding, altitude, etc.)Red blood cells are formed by differentiation of hematopoietic <stem cells> (blood cells with potential to become any mature blood cell) in order to replace red blood . This process is called erythropoiesis. In the very early stages of this process, cells are not fully committed to becoming red blood cells and they also have the potential to become white blood cells as well as platelets. Although DBA is considered to be a pure red blood cell disorder, evidence from a variety of research laboratories points to a cellular defect that is present not only in the red blood cell precursors but cells at even earlier stages of development. In one study, 21 of the 28 patients with steroid refractory DBA were shown to have bone marrow abnormalities involving white blood cell and platelet production (1). Another study has shown that white blood cell production from bone marrows of patients with DBA is also impaired, suggesting that the disease affects cells that are not yet fully committed to becoming red blood cells (2). A more recent study shows that the defect in cell growth and maturation is evident in multipotent progenitor cells that have not committed to becoming red blood cells.

The first of at least three or more genes involved in the development of anemia in patients with DBA has recently been identified as the RPS-19 gene located on chromosome 19 (4). Approximately twenty-five per cent of patients with DBA are found to have a mutation in this gene. The RPS-19 gene encodes a protein called RPS-19 (Ribosomal Protein S-19). This protein is a part of the cellular protein production machinery called the ribosome. The ribosome is involved in the production of all proteins produced in the cell. However, RPS-19 has functions other than involvement in protein synthesis. RPS-19 protein is shown to be present in high amounts during the early stages of red blood cell maturation and has been shown to decrease with maturation (5). It was shown that very early red blood cells from patients with DBA have diminished ability to produce mature red blood cells. In laboratory tests done in cells from patients with DBA and the RPS-19 mutation, introduction of a normal RPS-19 gene into the early immature red blood cells seem to correct this defect (3, 6), Gene therapy for DBA has not yet been attempted and is a very long way from clinical trials.

Forty percent of the patients with DBA have a mutation in a gene or genes located in a wide region in the short arm of chromosome 8 (8p22.3-23) but a candidate gene has not been identified yet (7). There has been no success in pinpointing the genetic defect in the DBA patients who have neither RPS-19 mutation nor chromosome 8p22.3-23 mutation.

Clinical Studies:
Cyclosporine A:
In a study involving 22 patients, in which all patients were tried on steroids , 10 patients did not respond to steroids. Eight of these patients were treated with cyclosporine A (also called CSA) for 6 months. Four of these patients responded to CSA therapy (50%). A significant relationship between the cyclosporine dose and clinical response was also found in this study. The authors concluded that a trial of cyclosporine should be attempted in steroid-refractory patients (8).

Metaclopramide (Reglan):
Metaclopromide (brand name Reglan), a medication used to relieve the symptoms of nausea and vomiting, is also known to induce the release of prolactin, a hormone produced during lactation. In a pilot study, one adult DBA patient treated with metaclopromide (10 mg taken by mouth three times daily) had increased blood prolactin levels. This patient also had an increase in her hematocrit (an index of red blood cell mass in the bloodstream) and she was maintained on 10 mg once-a-day of metaclopramide with 6 years of independence from steroids or transfusions. Based upon this case, a trial of metaclopromide treatment for DBA was carried out. Fifteen patients were enrolled but 3 of them chose to discontinue medication due to fatigue and another three were removed from the trial since they did not comply with the treatment regimen. Therefore, nine of 15 patients enrolled in this study completed the 16 weeks of treatment and were evaluated. Three of 9 patients responded to this treatment suggesting that this treatment needs to be further explored as an alternative treatment modality for patients with refractory DBA (9). An international trial is planned in the near future.

Megadose steroids:
Dr. Sinasi Ozsoylu reported success in treating several cases of steroid refractory DBA patients by using very high dose steroids (also known as megadose treatment). To reach a definitive conclusion on the role of very high dose steroids in the treatment of DBA, Buchanan and colleagues carried out a clinical trial in nine patients with refractory-DBA. While 4 of 9 patients enrolled in the study failed to respond to megadose steroids, 5 of them showed an initial improvement followed by relapse as the steroid dose was being tapered. The authors concluded that very high dose steroid treatment was not effective in treatment of refractory DBA (10).

IL-3 treatment:
IL-3 is a protein that is involved in inducing and maintaining the growth and maturation of cells that have the potential to become red blood cells. Results from a European clinical trial with IL-3 involving 40 patients have shown that patients with DBA refractory to steroids are unlikely to respond to IL-3. (11). An American trial showed similar results, however, the toxicity of the drug and its lack of commercial availability preclude its use in the future (12).

Current Clinical Trials:
The most current information on active clinical trials sponsored by the National Institute of Health can be found on the web site clinicaltrials.gov. You can search this site for DBA-related trials by clicking here (http://clinicaltrials.gov/search/condition=diamond+blackfan+anemia)

Investigators with non-NIH sponsored studies approved by their Institutional Review Boards (IRB) are encouraged to contact the DBAR so their study may be listed.

As of May 14, 2003 there are three active clinical trials open to patients with DBA:

1. DBA is one of the inherited bone marrow failure syndromes with an increase risk for development of cancer. Dr. Blanche Alter of National Cancer Institute is studying the relationship between patients with inherited bone marrow failure syndromes and development of cancer. Her studies involve the determination of biological and clinical indicators to determine why a subgroup of patients develop cancer. Details of this study can be found at the clinicaltrials.gov web site or by clicking here (http://clinicaltrials.gov/show/NCT00027274)

2. Stem cells are the cells that give rise to a variety of blood cells including red blood cells. They normally reside in the bone marrow and do not leave the bone marrow until a certain level of maturation is completed. In order to obtain stem cells from the peripheral blood, donors are given a medication called G-CSF to force stem cells to come out of the bone marrow prematurely thus increasing their availability in peripheral blood. This process is called stem cell mobilization. The National Heart, Lung and Blood Institute (NHLBI), a branch of the National Institutes of Health is currently enrolling patients to obtain stem cells from their peripheral blood to use for research and to store for possible future transplantation. Details of this study can be found at the clinicaltrials.gov web site or by clicking here (http://clinicaltrials.gov/show/NCT00011505)

3. Current standard treatment options available to patients with DBA are corticosteroids (usually prednisone), blood transfusions, and stem cell transplantation (13). Alternative treatment options are explored in well designed clinical trials that will result in statistically meaningful results in order to understand whether the alternative treatment modality studied results in an outcome that is worse than, equal to, or better than the standard treatment methods. There are also studies called pilot studies that are designed to test whether an alternative treatment modality has any potential in the treatment of the disease. The National Heart, Lung, and Blood Institute (NHLBI) is currently piloting the combined use of ATG and cyclosporine in the treatment of DBA. Details of this study can be found at the clinicaltrials.gov web site or by clicking here (http://clinicaltrials.gov/show/NCT00001749)

References

1. Giri, N., Kang, E., Tisdale, J. F., Follman, D., Rivera, M., Schwartz, G. N., Kim, S., Young, N. S., Rick, M. E., and Dunbar, C. E. (2000) Clinical and laboratory evidence for a trilineage haematopoietic defect in patients with refractory Diamond-Blackfan anaemia. Br J Haematol 108, 167-175. http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10651740&dopt=Abstract .

2. Santucci, M. A., Bagnara, G. P., Strippoli, P., Bonsi, L., Vitale, L., Tonelli, R., Locatelli, F., Gabutti, V., Ramenghi, U., D'Avanzo, M., Paolucci, G., Rosito, P., Pession, A., and Freedman, M. H. (1999) Long-term bone marrow cultures in Diamond-Blackfan anemia reveal a defect of both granulomacrophage and erythroid progenitors. Exp Hematol 27, 9-18. http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9923439&dopt=Abstract

3. Hamaguchi, I., Flygare, J., Nishiura, H., Brun, A. C., Ooka, A., Kiefer, T., Ma, Z., Dahl, N., Richter, J., and Karlsson, S. (2003) Proliferation deficiency of multipotent hematopoietic progenitors in ribosomal protein S19 (RPS19)-deficient diamond-Blackfan anemia improves following RPS19 gene transfer. Mol Ther 7, 613-622. http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12351378&dopt=Abstract

4. Draptchinskaia, N., Gustavsson, P., Andersson, B., Pettersson, M., Willig, T. N., Dianzani, I., Ball, S., Tchernia, G., Klar, J., Matsson, H., Tentler, D., Mohandas, N., Carlsson, B., and Dahl, N. (1999) The gene encoding ribosomal protein S19 is mutated in Diamond-Blackfan anaemia. Nat Genet 21, 169-175. http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9988267&dopt=Abstract

5. Da Costa, L., Narla, G., Willig, T. N., Peters, L. L., Parra, M., Fixler, J., Tchernia, G., and Mohandas, N. (2003) Ribosomal protein S19 expression during erythroid differentiation. Blood 101, 318-324. http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12393682&dopt=Abstract

6. Hamaguchi, I., Ooka, A., Brun, A., Richter, J., Dahl, N., and Karlsson, S. (2002) Gene transfer improves erythroid development in ribosomal protein S19- deficient Diamond-Blackfan anemia. Blood 100, 2724-2731. http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12718904&dopt=Abstract

7. Gazda, H., Lipton, J. M., Willig, T. N., Ball, S., Niemeyer, C. M., Tchernia, G., Mohandas, N., Daly, M. J., Ploszynska, A., Orfali, K. A., Vlachos, A., Glader, B. E., Rokicka-Milewska, R., Ohara, A., Baker, D., Pospisilova, D., Webber, A., Viskochil, D. H., Nathan, D. G., Beggs, A. H., and Sieff, C. A. (2001) Evidence for linkage of familial Diamond-Blackfan anemia to chromosome 8p23.3-p22 and for non-19q non-8p disease. Blood 97, 2145-2150. http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11264183&dopt=Abstract

8. El-Beshlawy, A., Ibrahim, I. Y., Rizk, S., and Eid, K. (2002) Study of 22 Egyptian patients with Diamond-Blackfan anemia, corticosteroids, and cyclosporin therapy results. Pediatrics 110, e44. http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12359817&dopt=Abstract

9. Abkowitz, J. L., Schaison, G., Boulad, F., Brown, D. L., Buchanan, G. R., Johnson, C. A., Murray, J. C., and Sabo, K. M. (2002) Response of Diamond-Blackfan anemia to metoclopramide: evidence for a role for prolactin in erythropoiesis. Blood 100, 2687-2691. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12351372&dopt=Abstract

10. Buchanan, G. R. (2001) Oral megadose methylprednisolone therapy for refractory Diamond- Blackfan anemia. International Diamond-Blackfan Anemia Study Group. J Pediatr Hematol Oncol 23, 353-356. http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11563769&dopt=Abstract

11. Ball, S. E., Tchernia, G., Wranne, L., Bastion, Y., Bekassy, N. A., Bordigoni, P., Debre, M., Elinder, G., Kamps, W. A., Lanning, M., and et al. (1995) Is there a role for interleukin-3 in Diamond-Blackfan anaemia? Results of a European multicentre study. Br J Haematol 91, 313-318. http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8547067&dopt=Abstract

12. Gillio, A. P., Faulkner, L. B., Alter, B. P., Reilly, L., Klafter, R., Heller, G., Young, D. C., Lipton, J. M., Moore, M. A., and O'Reilly, R. J. (1993) Treatment of Diamond-Blackfan anemia with recombinant human interleukin- 3. Blood 82, 744-751. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8338944&dopt=Abstract

13. Vlachos, A., Federman, N., Reyes-Haley, C., Abramson, J., and Lipton, J. M. (2001) Hematopoietic stem cell transplantation for Diamond Blackfan anemia: a report from the Diamond Blackfan Anemia Registry. Bone Marrow Transplant 27, 381-386. http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11313667&dopt=Abstract