HPA-1a Negative Platelets

• Platelet-specific antigen-negative platelets (HPA-1a negative platelets) are used for alloimmune thrombocytopenia and neonatal alloimmune thrombocytopenia (NAIT).
• Platelet-specific antigen-negative platelets (HPA-1a negative platelets) are available under the following different brand names: N/A.
• Dosages of Platelet Specific Antigen Negative Platelets (HPA-1a Negative Platelets):
• There is no difference in dosing platelet-specific antigen negative platelets compared to standard platelet dosing.

Dosages of HPA-1a Negative Platelets:

Dosage Considerations – Should be Given as Follows:

Alloimmune Thrombocytopenia

• There is no difference in dosing platelet-specific antigen negative platelets compared to standard platelet dosing.

Other Indications and Uses

• Platelet-specific antigen-negative units are indicated for neonates with neonatal alloimmune thrombocytopenia (NAIT) due to passively acquired antibodies against platelet-specific antigens.
• Platelet-specific antigen-negative units are also indicated for patients with alloimmune refractory thrombocytopenia due to antibodies against platelet-specific antigens.
• Additional studies, including platelet serology assays, may be useful. Alternatively, platelet crossmatching may be performed to screen for platelets that might have improved post-transfusion increments. The most common platelet-specific antibody implicated in alloimmune thrombocytopenia is HPA-1a; however, there are other high-frequency antigens that antigen-negative recipients can form antibodies against leading to alloimmune thrombocytopenia.
• Providing platelets for alloimmune thrombocytopenia vary by institution and your blood bank physician should be consulted for assistance.

Side effects of platelet specific antigen-negative platelets (HPA-1a negative platelets) include:

• Hemolytic Transfusion Reactions
• Febrile Non-Hemolytic Reactions
• Allergic Reactions ranging from hives to anaphylaxis
• Septic Reactions
• Transfusion Related Acute Lung Injury (TRALI)
• Circulatory Overload
• Transfusion Associated Graft Versus Host Disease
• Post-transfusion Purpura

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first.

• Platelet-specific antigen-negative platelets (HPA-1a negative platelets) have no listed severe interactions with other drugs.
• Platelet-specific antigen-negative platelets (HPA-1a negative platelets) have no listed serious interactions with other drugs.
• Platelet-specific antigen-negative platelets (HPA-1a negative platelets) have no listed moderate interactions with other drugs.
• Platelet-specific antigen-negative platelets (HPA-1a negative platelets) have no listed mild interactions with other drugs.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

Warnings

• This medication contains platelet-specific antigen-negative platelets (HPA-1a negative platelets). Do not take platelet-specific antigen-negative platelets (HPA-1a negative platelets) if you are allergic to platelet-specific antigen-negative platelets (HPA-1a negative platelets) or any ingredients contained in this drug.
• Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.

Contraindications

• Platelet antigen-specific negative units are not indicated in patients that have not demonstrated alloimmune thrombocytopenia due to a specific platelet antibody.

Effects of Drug Abuse

• No information available

Short-Term Effects

• See "What Are Side Effects Associated with Using Platelet Specific Antigen Negative Platelets (HPA-1a Negative Platelets)?”

Long-Term Effects

• See "What Are Side Effects Associated with Using Platelet Specific Antigen Negative Platelets (HPA-1a Negative Platelets)?”

Cautions

• Ordering platelet-specific antigen negative units may require a marked time delay of days to weeks or may not even be possible. Consult your blood bank physician and/or hematologist for recommendations in managing bleeding patients with alloimmune thrombocytopenia.
• Since NAIT is a transient problem due to passively acquired antibodies, other strategies such as obtaining washed (and irradiated) maternal platelets or increasing the dosage of untested platelets may be attempted. Consultation with your blood bank physician and/or hematologist is advised.

Pregnancy and Lactation

• See platelet monograph for pregnancy/lactation information.