Platelet E-News – October 13, 2006

This e-newsletter is a monthly publication of The Platelet Disorder Support Association. The information in this newsletter is for educational purposes only. For advice on your unique medical condition, please consult a health care professional.

Contents:

  • Childhood ITP: Special Issue of “Pediatric Blood & Cancer”
    • More Research Needed on Splenectomy in Children
    • Anti-D May be Better than IVIG
    • Rituximab Worth Trying before Splenectomy
  • Hospitals Struggling to Access IVIG at Federal Program’s Discount Prices
  • Patient Groups Call for Patient-Centered Approach to Healthcare
  • National Geographic Explores Chemical Exposures
  • Just How Does IVIG Work in ITP?
  • Can a Monoclonal Antibody Replace IVIG?
  • Platelets Play Key Role in Liver Regeneration
  • Brain Communicates with Spleen to Fight Sepsis
  • PDSA Introduces New Logo
  • PDSA Conference 2006 DVDs Available (advertisement)
  • Natural Herbal Solutions Developed by MDs (advertisement)

 

CHILDHOOD ITP: SPECIAL ISSUE OF “PEDIATRIC BLOOD & CANCER”

Pediatric Blood & Cancer is a monthly, international medical journal that covers research on blood disorders and cancers. A special issue (Volume 47, Issue S5, October 15, 2006) reports on the 2nd Intercontinental Childhood ITP Study Group (ICIS) Expert Meeting. Studies cover a broad spectrum, including diagnosis, treatment, epidemiology, etiology, biology, and molecular and clinical genetics of these diseases.

The table of contents and subscription information is available at: http://www3.interscience.wiley.com/cgi-bin/jtoc/106561790/
Individuals can order a copy for $27 by contacting the subscription department of John Wiley and Sons at 1-800-825-7550.

Articles in the Special Issue Pediatric Blood & Cancer include:

MORE EVIDENCE-BASED RESEARCH NEEDED ON SPLENECTOMY IN CHILDREN

In a discussion of critical and unsolved issues in splenectomy in children with chronic ITP, researchers from Austria note that, while chronic ITP accounts for 20-30% of all pediatric cases, spontaneous remission occurs in about one-third of the children. Severe chronic ITP (persistent platelet count <30 x109/L and clinically significant hemorrhage), which could justify splenectomy, accounts for just 2-3% of all ITP cases. Yet, the frequency of splenectomy for chronic ITP, depending on the study, varies between 10% and 40%. They note that existing recommendations are based on expert opinion rather than clinical trials, and suggest a well-designed prospective trial, perhaps through the Intercontinental Childhood ITP Study Group, to address existing controversies and “better define the value of splenectomy in the management of chronic ITP in children.”

Minkov M. Critical issues concerning splenectomy for chronic idiopathic thrombocytopenic purpura in childhood. Pediatric Blood Cancer 2006;47:734-736

ANTI-D SAFE IN CLASSIC CHILDHOOD ITP, BUT SIDE EFFECTS OCCUR

The Danish authors reviewed 25 papers on anti-D (Win Rho SDF® in the U.S.) treatment in childhood ITP published between 1986 and 2006 and found that intravenous anti-D seems safe in classic childhood ITP with fewer side effects than IVIG. However, hemolysis, or a breaking apart of red blood cells, is a concern. Subcutaneous anti-D may be better tolerated, but must be studied first.

Kjaersgaard M, Hasle H. A review of anti-D treatment of childhood idiopathic thrombocytopenic purpura. Pediatric Blood Cancer 2006;47:717-720.

RITUXIMAB SHOULD BE TRIED BEFORE SPLENECTOMY IN CHILDREN

Rituximab is a monoclonal antibody that results in depletion of B-cells, which may stifle the autoimmune response that occurs in ITP. Researchers from The Netherlands review treatment options for children with ITP that is chronic and symptomatic. Most treatments aim to reduce platelet destruction. Steroids and IVIG are most often used, yet their effects are temporary and side effects from long-term use can be serious. Anti-D (Win Rho SDF® in the U.S.) is an alternative to IVIG, but causes hemolysis in some patients. Splenectomy is often considered in children with ITP for 12-24 months who are refractory to the above-mentioned treatments. However, the risks from splenectomy are greater for children than adults, and more than half of children spontaneously recover after a period of years. They note, “ways to prevent or postpone splenectomy should be considered.” They found only three studies published on rituximab treatment, and each showed a similar efficacy—one third of children had a continuous response to treatment, though important side effects were possible. They conclude that in the small percentage of children whose ITP becomes chronic and symptomatic, intermittent treatment with steroids or IVIG is first choice. However, in non-responding disease or when side effects influence quality of life, treatment with rituximab is second-line treatment. Finally, they state, only those who fail rituximab treatment should proceed to splenectomy.”

Tamminga RYJ, Bruin MCA. Rituximab treatment for symptomatic chronic ITP. Pediatric Blood Cancer 2006;47:714-716.

HOSPITALS STRUGGLE TO ACCESS IVIG AT AFFORDABLE PRICES

The Public Hospital Pharmacy Coalition (PHPC) released a September 2006 survey stating that, along with a supply shortage of IVIG products, hospitals that serve many low-income patients face a widespread problem of accessing IVIG at discounted prices, which drug companies are required to provide under the federal “340B” program. Half of survey respondents stated they are unable to obtain sufficient IVIG to fulfill the needs of their patients. And close to 80% stated they are unable to purchase any IVIG at the discounted 340B prices.

A copy of the full report is at: http://www.phpcrx.org/documents/IVIG_report.pdf

The Department of Health and Human Services Office of the Assistant Secretary for Planning and Evaluation held a town hall meeting on Patient and Physician Concerns in Access to Intravenous Immunoglobulin (IVIG) in Arlington, VA, on September 28, 2006. Along with the Public Hospital Pharmacy Coalition, the Plasma Protein Therapeutics Association commented regarding efforts to assure access to IVIG in Medicare. A final report is expected to be released in early 2007. From the meeting website:

“Written comments are welcome from the public regardless of whether you attended the Town Hall Meeting or whether you made an oral presentation at the Town Hall Meeting. Written comments can be submitted either via e-mail to meetings@erg.com (subject: IVIG Meeting Comments) or via regular mail to ATTN: IVIG Meeting, ERG, 110 Hartwell Avenue, Lexington, MA 02421. Please note that electronic submissions are preferred due to delays in receiving U.S. Postal Mail. We are able to consider only those comments received in writing and/or via email by 5 p.m. EST on October 15, 2006.”

IAPO STUDY CALLS FOR MORE PATIENT-CENTERED APPROACH TO HEALTHCARE

A survey by the International Alliance of Patients’ Organizations (IAPO) randomly polled 1,200 members of patients’ organizations in 12 countries*and found three themes shared consistently regarding the accessibility of individualized treatment and healthcare information. Timely access to the best medicines and information is one of the primary concerns of those surveyed. Ninety five percent of members of patient organizations demand a right to participate as partners in making healthcare decisions that affect their lives. Finally, they indicated a strong belief that patients should shape healthcare policy decisions that affect their lives.
The study was supported by Pfizer.

* UK, Germany, France, Hungary, Austria, Czech Republic, Italy, Spain, Belgium, Sweden, Canada, Nigeria.

A summary of the study can be found on the IAPO website: www.patientsorganizations.org

NATIONAL GEOGRAPHIC EXPLORES ENVIRONMENTAL TRIGGERS

The October 2006 issue of National Geographic contains an article, “The Pollution Within.” Author David Ewing Duncan writes about his “journey of chemical self-discovery.” He was tested for 320 chemicals that any of us can pick up from food, drink, the air we breathe, or the products that touch our skin. He was screened for older chemicals such as DDT and PCBs, pollutants like lead, mercury, and dioxins; newer pesticides and plastic ingredients; and the compounds that make pans nonstick and fabrics water-resistant and fire-safe. The article details how he thinks he was exposed to each and explores the known effects of some of these chemicals.

The article is online: http://www3.nationalgeographic.com/ngm/0610/feature4/index.html

JUST HOW DOES IVIG WORK IN ITP?

The mechanism by which IVIG can improve the condition of patients with ITP is unclear. Using a mouse model with ITP, the researchers probe the efficacy of IVIG and offer a model for refining therapy in ITP. They demonstrated that cells in the innate immune system, but not lymphocytes, are central for the success of IVIG in ITP.

Siragam V, Crow AR, Brinc D, et al. Intravenous immunoglobulin ameliorates ITP via activating Fcgamma receptors on dendritic cells. Nat Med 2006;12;688-692.

CAN A MONOCLONAL ANTIBODY REPLACE IVIG?

This research team is exploring ways to improve upon IVIG’s impact using monoclonal antibodies. They generated highly stable immune complexes by mixing IVIG with monoclonal anti-human IgG (immunoglobulin G). The complexes were more potent than IVIG in preventing or reversing antibody-induced platelet reduction in mice. Also, adding the antibody directly to human serum, they were able to generate the immune complex that exhibited the same activity as that prepared in the laboratory. They suggest that it may be possible to develop a substitute for IVIG by forming immune complexes using IgG from ITP patients and the anti-human IgG monoclonal antibody.

Bazin R, Lemieux R, Tremblay T. Reversal of immune thrombocytopenia in mice by cross-linking human immunoglobulin G with a high-affinity monoclonal antibody. British J Haematology 2006;135:97-100.

PLATELETS PLAY KEY ROLE IN LIVER REGENERATION

This paper points to a surprising role for platelets in liver regeneration. They carry biologically active molecules in their granules that they deposit at sites of vascular injury. These molecules include peptide growth factors, enzymes, and enzyme inhibitors. In the case of liver regeneration, serotonin appears to be the important molecule carried by platelets. In a mouse model in which 70% of the liver is removed, mice with low platelet counts or nonfunctioning platelets could not regenerate their livers. They showed that platelets aid in regeneration by bringing serotonin to serotonin receptors on the liver, which increase three-fold or more after part of the liver is removed.

Lesurtel M, Graf R, Aleil B, et al. Platelet-derived serotonin mediates liver regeneration. Science 2006;312:104-7.

BRAIN COMMUNICATES WITH SPLEEN TO FIGHT SEPSIS

Researchers have found in studies in mice that the brain somehow senses the presence of potentially lethal sepsis and sends a signal via the efferent vagus nerve to the spleen to shut down production of inflammatory cytokines. When a spleen does not exist, the body’s response to the sepsis is ineffectual. Researchers are exploring other means of activating the anti-inflammatory pathway, using drugs or electrical stimulation of the vagus nerve. In the September – October 2006 issue of The Hematologist, Dr. Roy Silverstein reviewed the work and wrote, “These studies may explain in part why patients without spleens are more likely to develop sepsis syndromes in the setting of certain bacterial infections.”

Huston JM, Ochani M, Rosas-Ballina M. et al. Splenectomy inactivates the cholinergic anti-inflammatory pathway during lethal endotoxemia and polymicrobial sepsis. J Exp Med 2006;203:1623-1628.

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