Hemolytic disease of the newborn (anti-Kell)
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2007-01-22T23:32:03Z
Snowmanradio
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/* Prevention */ management
{{DiseaseDisorder infobox |
Name = HDN due to anti-Kell alloimmunization|
ICD10 = {{ICD10|P|55|8|p|50}} |
ICD9 = {{ICD9|773.2}} |
}}
'''Hemolytic disease of the newborn (anti-Kell<sub>1</sub>)''' is the second most common cause of severe hemolytic diseases of newborns ([[HDN]]) after [[Rh disease]]. Anti-Kell<sub>1</sub> is becoming relatively more important as prevention of Rh disease is becoming more and more effective.
Hemolytic disease of the newborn (anti-Kell<sub>1</sub > is caused by a mis-match between the [[Kell antigen system|Kell antigens]] of the mother and fetus. About 91% of the population are Kell<sub>1</sub> negative and about 9% are Kell<sub>1</sub> positive. A fraction of a percentage are [[homozygous]] for Kell <sub>1</sub>. Therefore, about 4.5% of babies of a Kell<sub>1</sub> negative mother are Kell<sub>1</sub> positive.
The disease results when maternal [[antibodies]] to Kell<sub>1</sub> are transferred to the fetus across the [[placenta|placental barrier]]. These antibodies can cause severe [[anemia]] by interfering with the early proliferation of [[red blood cells]] as well as causing [[alloimmune]] hemolysis. Very severe disease can occur as early as 20 weeks gestation. [[Hydrops fetalis]] can also occur early. The finding of anti-Kell antibodies in an antenatal screening blood test ([[coombs test#indirect coombs test|indirect Coombs test]]) is an indication for early referral to a specialist service for assessment, management and treatment.
== Cause ==
Mothers who are negative for the Kell<sub>1</sub> antigen develop antibodies after being exposed to red blood cells that are positive for Kell<sub>1</sub>. Over half of the cases of hemolytic disease of the newborn owing the anti-Kell antibodies are caused by multiple blood transfusions, with the remainder due to a previous pregnancy with a Kell<sub>1</sub> positive baby.
==Prevention==
Suggestions have been made that women of child bearing age or young girls should not be given a [[Blood transfusion|transfusion]] with Kell<sub>1</sub> positive blood. Donated blood is not currently screened (in the U.S.A.) for the Kell blood group antigens as it is not considered cost effective at this time.
It has been hypothesized that IgG anti-Kell<sub>1</sub> antibody injections would prevent sensitization to RBC surface Kell<sub>1</sub> antigens in a similar way that IgG anti-D antibodies ([[Rho(D) Immune Globulin]]) are used to prevent [[Rh disease]], but the methods for IgG anti-Kell<sub> 1</sub> antbodies have not been developed at the present time.
==Management==
It can be detected by routine antenatal antibody screening blood tests ([[coombs test#indirect coombs test|indirect Coombs test]]) in a similar way to [[Rh disease]]. The treatment of hemolytic disease of the newborn (anti-Rhc) is similar to the management of [[Rh disease]].
==anti-Kell<sub>2</sub>, anti-Kell<sub>3</sub> and anti-Kell<sub>4</sub> antibodies==
Hemolytic disease of the newborn can also be caused by anti-Kell<sub>2</sub>, anti-Kell<sub>3</sub> and anti-Kell<sub>4</sub> IgG antibodies. These are rarer and generally the disease is milder.
==References==
*Geifman-Holtzman O, Wojtowycz M, Kosmas E, and Artal R. Female allo-immunization with antibodies known to cause hemolytic disease. Obstetrics and Gynecology 1997 89, 272-275
*Wiener CP, and Widness JA. Decreased fetal erythropoiesis and hemolysis in Kell hemolytic anemia. American Journal of Obstetrics and Gynecology. 1996 174: 547-55
==See also==
*[[Coombs test]]
*[[Hematology]]
*[[Hemolytic anemia]]
*[[Kell antigen system]]
{{HDN}}
[[Category:Blood disorders]]
[[Category:Hematology]]
[[Category:Obstetrics]]
[[Category:Pediatrics]]
[[Category:Transfusion medicine]]