Neonatal alloimmune thrombocytopenia

Neonatal alloimmune thrombocytopenia
Fetal and Neonatal Alloimmune Thrombocytopenia
Classification and external resources
ICD-10 P61.0
ICD-9 776.1
DiseasesDB 33767
eMedicine med/3256 med/3480

Neonatal Alloimmune Thrombocytopenia (NAITP or NAIT or NAT for short; or fetal and neonatal alloimmune thrombocytopenia, FNAIT, feto-maternal alloimmune thrombocytopenia, FMAITP or FMAIT) is a disease that affects fetuses and newborns. Genetic differences between the fetus and mother may result in the expression of certain antigens by fetal platelets, not expressed by the mother. Fetomaternal transfusions result in the recognition of these antigens by the mother's immune system as non-self, with the subsequent generation of allo-reactive antibodies which cross the placenta. NAIT, hence, is caused by transplacental passage of maternal platelet-specific alloantibody and rarely human leukocyte antigen (HLA) allo-antibodies [1] (which are expressed by platelets) to fetuses whose platelets express the corresponding antigens. NAIT occurs in somewhere between 1/800 [2] and 1/5000 [3] live births. More recent studies of NAIT seem to indicate that it occurs in around 1/600 live births in the Caucasian population.[4]

Contents

Signs and Symptoms

Frequently, the thrombocytopenia is mild and the affected neonates remain largely asymptomatic. In these cases, therapeutic interventions are not indicated. In case of severe thrombocytopenia, the neonates may exhibit hemorrhagic complication at or a few hours after delivery. The most serious complication is intracranial hemorrhage, leading to death in approximately 10% or neurologic sequelae in 20% of cases.

Diagnosis

Although there are currently no widespread tests for NAIT, platelet antigen genotyping and platelet antibody identification can be performed on the maternal and paternal blood to determine the exact nature of the incompatibility.

Causes

About 80% of cases of NAIT are caused by antibodies against platelet antigen HPA-1a, 15% by anti-HPA-5b, and 5% by other antibodies.[5] Unlike the hemolytic disease, NAIT occurs during the first pregnancy in up to 50% of cases, and the affected fetuses may develop severe thrombocytopenia (<50,000 /μL) very early during pregnancy. Usually, the thrombocytopenia increases as gestation progresses. In utero intracranial hemorrhage occurs in about 10% of affected cases. This complication may also take place before 20 weeks of gestation. The recurrence of NAIT been estimated to be more than 80% in subsequent pregnancies with incompatible fetuses.

Treatment

During Pregnancy

The use of Intravenous immunoglobulin (IVIG) during pregnancy and immediately after birth has been shown to help reduce or alleviate the effects of NAIT in infants and reduce the severity of thrombocytopenia. The most common treatment is weekly IVIG infusions at a dosage of 1g/kg beginning at 16 to 28 weeks of pregnancy, depending on the severity of the disease in the previous affected child, and continuing until the birth of the child.[6][7] In some cases this dosage is increased to 2g/kg and/or combined with a regiment of prednisone depending on the exact circumstances of the case. Although this treatment has not been shown to be effective in all cases it has been shown to reduce the severity of thrombocytopenia in some. Also it is suspected that (though not understood why) IVIG provides some added protection from ICH (intercranial hemorrhage) to the fetus.

After Birth

The most rapidly effective treatment in infants with severe hemorrhage and/or severe thrombocytopenia (<30x109/L) is the transfusion of compatible platelets (i.e. platelets from a donor who, like the mother lacks the causative antigen). Additionally if the thrombocytopenia in the infant at birth is not severe enough to warrant a transfusion of platelets (>30x109/L) an infusion of IVIG (1g/kg/day for two days) in the infant has been shown to rapidly increase platelet count and reduce the risk of related injury.

References

  1. ^ Porcelijn L, Van den Akker ES, Oepkes D. Fetal thrombocytopenia (Review). Semin Fetal Neonatal Med 2008 Aug;13(4):223-30.
  2. ^ Doctor Cecil Kaplan (2003-11-01). "Fetal and Neonatal Alloimmune Thrombocytopenia". Orphanet Encyclopedia. http://www.orpha.net/data/patho/GB/uk-NAIT.pdf. Retrieved 2007-09-23. 
  3. ^ Janice G. McFarland, Richard H. Aster, James E. Bussel, John G. Gianopoulos, Rebecca S. Derbes, and Peter J. Newman (1991-11-01). "Prenatal Diagnosis of Neonatal Alloimmune Thrombocytopenia Using Allele-Specific Oligonucleotide Probes". Blood Journal. http://bloodjournal.hematologylibrary.org/cgi/reprint/78/9/2276. Retrieved 2007-09-23. 
  4. ^ Kamphuis MM, Paridaans N, Porcelijn L, De Haas M, van der Schoot CE, Brand A, Bonsel GJ, Oepkes D. Screening in pregnancy for fetal or neonatal alloimmune thrombocytopenia: systematic review. BJOG 2010 Jul 8.(Epub ahead of print)
  5. ^ Mueller-Eckhardt C, Kiefel V, Grubert A, Kroll H, Weisheit M, Schmidt S, et al. 348 cases of fetal alloimmune thrombocytopenia. Lancet 1989;1: 363-6.
  6. ^ Lynnae Millar, MD (2006-06-29). "Immune Thrombocytopenia and Pregnancy". eMedicine. http://www.emedicine.com/med/topic3256.htm. Retrieved 2007-09-19. 
  7. ^ van den Akker ES, Oepkes D, Lopriore E, Brand A, Kanhai HH.Noninvasive antenatal management of fetal and neonatal alloimmune thrombocytopenia: safe and effective. BJOG 2007 Apr;114(4):469-73.

External links

There is a support group for those with this condition

NAIT Homepage


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • neonatal thrombocytopenia — neonatal alloimmune thrombocytopenia immune thrombocytopenia that results when platelets of the fetus express an antigen that is lacking on maternal platelets; fetal platelets enter the maternal circulation and stimulate the production of… …   Medical dictionary

  • Thrombocytopenia — Infobox Disease Name = Thrombocytopenia Caption = DiseasesDB = 27522 ICD10 = ICD10|D|69|6|d|65, ICD10|P|61|0|p|50 ICD9 = ICD9|287.3, ICD9|287.4, ICD9|287.5 ICDO = OMIM = 188000 OMIM mult = OMIM2|313900 MedlinePlus = 000586 eMedicineSubj =… …   Wikipedia

  • Fetale Alloimmune Thrombozytopenie — Klassifikation nach ICD 10 P61.0 Transitorische Thrombozytopenie beim Neugeborenen Thrombozytopenie beim Neugeborenen durch: Isoimmunisierung …   Deutsch Wikipedia

  • Neonatale Alloimmune Thrombozytopenie — Klassifikation nach ICD 10 P61.0 Transitorische Thrombozytopenie beim Neugeborenen Thrombozytopenie beim Neugeborenen durch: Isoimmunisierung …   Deutsch Wikipedia

  • Alloimmun-Thrombozytopenie — Klassifikation nach ICD 10 P61.0 Transitorische Thrombozytopenie beim Neugeborenen Thrombozytopenie beim Neugeborenen durch: Isoimmunisierung …   Deutsch Wikipedia

  • FAIT — Klassifikation nach ICD 10 P61.0 Transitorische Thrombozytopenie beim Neugeborenen Thrombozytopenie beim Neugeborenen durch: Isoimmunisierung …   Deutsch Wikipedia

  • NAIT — Klassifikation nach ICD 10 P61.0 Transitorische Thrombozytopenie beim Neugeborenen Thrombozytopenie beim Neugeborenen durch: Isoimmunisierung …   Deutsch Wikipedia

  • List of diseases (F) — A list of diseases in the English wikipedia.DiseasesTOC FaFab* Fabry s diseaseFacFace Faci* Faces syndrome * Facial asymmetry temporal seizures * Facial clefting corpus callosum agenesis * Facial dysmorphism macrocephaly myopia Dandy Walker type… …   Wikipedia

  • Nat — Not to be confused with Gnat. Nat or NAT may refer to: Nat., an abbreviation for Natural Nat (spirit), a Burmese spirit worshipped in Myanmar (Burma) in conjunction with Buddhism Nat (Wild Cards), a slang term from the novels referring to normal… …   Wikipedia

  • NAIT — stands for: North American Islamic Trust, an organization in Plainfield, Indiana, that owns Islamic properties Northern Alberta Institute of Technology Neonatal alloimmune thrombocytopenia National Association of Industrial Technology This… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”