scholarly journals Case Of NAIT Causing Severe Thrombocytopenia due to Anti-HLA Class I

2021 ◽  
Vol 5 (0-2) ◽  
pp. 21
Author(s):  
Noor Aqilah Binti Ashamuddin ◽  
Sabariah Binti Mohd Noor ◽  
Irni Binti Mohd Yasin
Keyword(s):  
Placental Transfer ◽  
Serum Antibody ◽  
Hla Class I ◽  
Premature Baby ◽  
Maternal Serum ◽  
Class I ◽  
Severe Thrombocytopenia ◽  
Platelet Antigen ◽  
Obstetric Management ◽  
Alloimmune Thrombocytopenia

Neonatal alloimmune thrombocytopenia (NAIT) is the leading cause of thrombocytopenia in otherwise healthy new-born. (1,2) Maternal antibodies raised against paternally inherited alloantigen carried on fetal platelet causing NAIT. Maternal IgG antibodies passed through to the fetal via the placenta, attack and cause the destruction of the fetal platelet. (3) We present a case of NAIT without any complications in a premature baby (35 weeks) with VACREL association, G6PD deficiency, left calcified cephalohaematoma, cardiomegaly and hypospadias with severe thrombocytopenia (platelet counts is 23 109/L) at day two of life and received twice platelet transfusion. Platelet count initially 123 109/L at birth but significantly drop and persistently less than 50 109/L until day 10 of life before it normalized. Maternal serum antibody screening was negative, but platelet immunology test detected maternal platelet-reactive antibody Anti-HLA Class I and correlates with incompatible parental crossmatch indicating that parent had “platelet-antigen incompatibility”. The goal of obstetric management is to identify pregnancies at risk and prevent intracranial haemorrhage. (4) There is no evidence to support routine screening for pregnancies as per current practice. (2, 5) The latest treatments include maternal administration of intravenous immunoglobulin to suppress maternal antibody production and or to reduce placental transfer of antibodies; with or without steroids during antepartum period besides planning of mode, timing and method of delivery. (2, 5, 6, 7) This is a rare and unique case of NAIT secondary to Anti-HLA Class I antibody and hence clinician should be au fait with the diagnosis and management as it is infrequent among Malaysian.International Journal of Human and Health Sciences Supplementary Issue-2: 2021 Page: S21

An Unusual Case of Fetal/Neonatal Alloimmune Thrombocytopenia

2019 ◽  
Vol 152 (Supplement_1) ◽  
pp. S151-S152
Author(s):  
Maryna Vazmitsel ◽  
Dong Chen ◽  
Barbara Gruner ◽  
Emily Coberly
Keyword(s):  
Platelet Count ◽  
Hla Class I ◽  
Maternal Blood ◽  
Term Infant ◽  
Blood Type ◽  
Class I ◽  
Severe Thrombocytopenia ◽  
Antibody Testing ◽  
Torch Infection ◽  
Alloimmune Thrombocytopenia

Abstract Objectives Fetal/neonatal alloimmune thrombocytopenia (FNAIT) occurs when maternal IgG alloantibodies against paternal human platelet antigens (HPA) cross the placenta and cause the destruction of fetal platelets. The vast majority (up to 95%) of FNAIT cases are caused by antibodies against HPA-1a or HPA-5b antigens, while the remaining cases are usually due to antibodies against a variety of other HPA antigens. Cases of FNAIT due to anti-HLA antibodies are extremely uncommon and have only rarely been reported. We present a case of FNAIT suspected to be caused by anti-HLA class I alloantibodies. Methods The patient is a term infant boy born to a 32-year-old G2T2L2 mother. The mother had a previous diagnosis of Still disease (an adult form of systemic juvenile rheumatoid arthritis) but experienced complete resolution of symptoms and was off all treatment during the pregnancy. At birth, laboratory testing revealed isolated severe thrombocytopenia (platelet count 38,000/mcL) in an otherwise healthy-appearing infant. Results The infant had no evidence of bleeding, and testing for TORCH infection, sepsis, and DIC was negative. The maternal blood type was O positive. The maternal platelet count was normal. FNAIT was suspected and the infant was given two platelet transfusions from the same HPA 1a and 5b antigen-negative donor with no significant or sustained improvement in platelet count. Maternal platelet antibody testing subsequently revealed an absence of HPA antibodies, but anti-HLA class I alloantibodies were present. The infant was treated with three subsequent doses of IVIg with improvement in platelet count. No significant hemorrhage occurred. Conclusion HLA class I antibodies are commonly found in multiparous women but are not generally thought to cause significant fetal complications during subsequent pregnancies. This case suggests that, although rarely reported, HLA class I alloantibodies may be capable of causing FNAIT.

HLA class I and HPA9b related fetal‐neonatal alloimmune thrombocytopenia

2021 ◽  
Author(s):  
Sara Barbieri ◽  
Alessandro Copeta ◽  
Nicoletta Revelli ◽  
Alberto Malagoli ◽  
Alessia Montani ◽  
...  
Keyword(s):  
Hla Class I ◽  
Class I ◽  
Alloimmune Thrombocytopenia

A Screening and Intervention Program Reducing Mortality and Serious Morbidity Associated with Neonatal Alloimmune Thrombocytopenia.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1232-1232
Author(s):  
Jens Kjeldsen-Kragh ◽  
Mette K. Killie ◽  
Geir Tomter ◽  
Elzbieta Golebiowska ◽  
Helene Pedersen ◽  
...  
Keyword(s):  
Platelet Count ◽  
Intervention Program ◽  
Human Platelet ◽  
Fetal Brain ◽  
University Hospital ◽  
Severe Thrombocytopenia ◽  
Platelet Antigen ◽  
Human Platelet Antigen ◽  
Alloimmune Thrombocytopenia

Abstract Background: Neonatal alloimmune thrombocytopenia (NAIT) is most frequently caused by antibodies against the human platelet antigen (HPA) 1a. The objective of the present study was to identify HPA 1a negative women, and to offer them an intervention program aimed to reduce morbidity and mortality of NAIT. Methods: A total of 100,448 pregnant women were HPA 1 typed. The HPA 1a negative women were screened for anti-HPA 1a, which was quantified when present. Immunized women were referred to a university hospital for clinical follow-up, including ultrasonographic examination of the fetal brain. Caesarean section was performed 2–4 weeks prior to term with platelets from HPA 1bb donors reserved for immediate transfusion if petechiae were present and/or if platelet count was < 35 × 109/L. Results: Of all women typed 2.1% were HPA 1a negative. Anti-HPA 1a was detected in 210 of 1,990 HPA 1a negative women. A total of 170 pregnancies in 154 HPA 1a negative women were managed according to the intervention program. These women gave birth to 161 HPA 1a positive children of whom 55 had severe thrombocytopenia (<50 × 109/L) including two with ICH. There were no intrauterine deaths. In 13 previously published prospective studies comprising 131,465 women of whom 2,290 were HPA 1a negative, there were 10 cases with severe NAIT-related complications (3 intrauterine deaths and 7 neonates with ICH), which are significantly higher than in our study (p < 0.05). Conclusions: The screening and intervention program seems to reduce mortality and serious morbidity associated with NAIT.

scholarly journals Anti-HLA Antibodies in Neonatal Alloimmune Thrombocytopenia - Is There Any Clinical Significance?

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4647-4647 ◽  
Author(s):  
Lilach Bonstein ◽  
Nardeen Atweh ◽  
Nuhad Haddad ◽  
Yariv Fruchtman
Keyword(s):  
Platelet Count ◽  
Antibody Titer ◽  
Conflicts Of Interest ◽  
Hla Class I ◽  
Class I ◽  
Hla Antibodies ◽  
Neonatal Thrombocytopenia ◽  
Alloimmune Thrombocytopenia ◽  
Sample Case ◽  
Hla Antibody

Abstract Background: Neonatal alloimmune thrombocytopenia (NAIT) is caused by maternal alloantibodies raised against paternally inherited alloantigens carried on fetal platelets. Platelets express both HLA class I and specific human platelet antigens (HPA). Although anti-HLA class I antibodies are often detectable in pregnant women, NAIT is considered to be mainly associated with antibodies against HPA. Cases where NAIT has been caused by antibodies against HLA class I are relatively rare and the role of these antibodies in NAIT remains debatable. We hereby describe a sample case of NAIT proved to be caused solely by anti-HLA antibodies and discuss laboratory measures aimed at identification of pregnancies at risk of NAIT related to anti-HLA class I antibodies based on a series of similar cases. Methods: This sample case presents laboratory work-up on a young mother who delivered her first son with a platelet count of 20x109/L, minor petechiae and normal WBC count. Thrombocytopenia in the newborn resolved spontaneously two weeks after birth. Laboratory investigation included platelet immunofluorescence test (PIFT), monoclonal antibody-specific immobilization of platelet antigens (MAIPA) assay, genotyping of both parents and the newborn for platelet antigens, including rare antigens, and HLA antibody identification using the panel reactive antibodies (PRA) assay (Luminex, USA). A serum sample of this mother, drawn during her second pregnancy, and those of ten other women referred to our laboratory with a similar obstetric history of neonatal thrombocytopenia, were evaluated for the anti-HLA antibody titer using the MAIPA assay. Results: The Rambam Platelet & Neutrophil Immunology Laboratory, as well as 32 other laboratories worldwide, that participated in the 2014 International Workshop organized by the ISBT Platelet Immunobiology Working Party failed to detect anti-HPA antibodies in the mother's serum during her second pregnancy, despite using the most sensitive serological analysis and molecular methods. Only strong anti-HLA antibodies with no single specificity were found in the analyzed samples by all the laboratories. Her second child was born by caesarean section with a platelet count of 50x109/L and maternal anti-HLA antibodies were found in his serum and on his platelets. The anti-HLA antibody titer of the mother, determined by the MAIPA assay, was greater than 1:1024, with antibodies being multi-specific, as demonstrated by PRA. The anti-HLA antibody titer ≥1:16 was found to correlate with low platelet counts in the additional ten cases tested, as opposed to the titer of ≤1:4 in cases with mild and not clinically significant neonatal thrombocytopenia. Conclusions: The presence of anti-HLA class I antibodies should be considered as a potential cause of NAIT, especially in cases with a very high titer of antibodies. The mechanism underlying the effect of these antibodies on fetal platelets needs to be further investigated. Disclosures No relevant conflicts of interest to declare.

scholarly journals Fetal/neonatal alloimmune thrombocytopenia: a systematic review of impact of HLA-DRB3*01:01 on fetal/neonatal outcome

2020 ◽  
Vol 4 (14) ◽  
pp. 3368-3377
Author(s):  
Jens Kjeldsen-Kragh ◽  
Dean A. Fergusson ◽  
Mette Kjaer ◽  
Lani Lieberman ◽  
Andreas Greinacher ◽  
...  
Keyword(s):  
Systematic Review ◽  
Prospective Studies ◽  
Retrospective Studies ◽  
Neonatal Outcome ◽  
Meta Analysis ◽  
Severe Thrombocytopenia ◽  
Platelet Antigen ◽  
Human Platelet Antigen ◽  
Neonatal Thrombocytopenia ◽  
Alloimmune Thrombocytopenia

Abstract The most common, severe cases of fetal and neonatal alloimmune thrombocytopenia among whites are caused by antibodies against human platelet antigen 1a (HPA-1a). The aims of this systematic review and meta-analysis are to determine the association between maternal HLA-DRB3*01:01 and: (1) HPA-1a-alloimmunization and (2) neonatal outcome in children born of HPA-1a-immunized women. A systematic literature search identified 4 prospective and 8 retrospective studies. Data were combined across studies to estimate pooled odds ratios (ORs) and the associated 95% confidence intervals (CIs). The population represented by the prospective studies was more than 150 000. In the prospective studies, there were 64 severely thrombocytopenic newborns (platelet count <50 × 109/L) of whom 3 had intracranial hemorrhage. The mothers of all 64 children were HLA-DRB3*01:01+. The number of severely thrombocytopenic children born of HPA-1a-alloimmunized women in the retrospective studies was 214; 205 of whom were born of HLA-DRB3*01:01+ women. For HLA-DRB3*01:01− women, the OR (95% CI) for alloimmunization was 0.05 (0.00-0.60), and for severe neonatal thrombocytopenia 0.08 (0.02-0.37). This meta-analysis demonstrates that the risk of alloimmunization and of having a child with severe thrombocytopenia are both very low for HPA-1a− women who are HLA-DRB3*01:01−.

scholarly journals Current Anti-HPA-1a Standard Antibodies React with the β3 Integrin Subunit but not with αIIbβ3 and αvβ3 Complexes

2019 ◽  
Vol 119 (11) ◽  
pp. 1807-1815 ◽  
Author(s):  
Behnaz Bayat ◽  
Annalena Traum ◽  
Heike Berghöfer ◽  
Silke Werth ◽  
Jieging Zhu ◽  
...  
Keyword(s):  
Tube Formation ◽  
Maternal Serum ◽  
Severe Thrombocytopenia ◽  
Integrin Subunit ◽  
Human Monoclonal Antibodies ◽  
Standard Material ◽  
Capture Assay ◽  
Β3 Integrin ◽  
Alloimmune Thrombocytopenia ◽  
And Control

Abstract Background Fetal/neonatal alloimmune thrombocytopenia (FNAIT) results from maternal alloantibodies (abs) reacting with fetal platelets expressing paternal human platelet antigens (HPAs), mostly HPA-1a. Anti-HPA-1a abs, are the most frequent cause of severe thrombocytopenia and intracranial hemorrhage (ICH). Objectives Titration of anti-HPA-1a in maternal serum using standard National Institute for Biological Standards and Control (NIBSC) 03/152 is one diagnostic approach to predict the severity of FNAIT. Recently, we found three anti-HPA-1a subtypes reacting with the β3 subunit independently or dependently from complexes with αIIb and αv. Endothelial cell-reactive anti-αvβ3 abs were found predominantly in cases with ICH. Our aim was to assess whether available standard material represents all anti-HPA-1a subtypes. Materials and Methods In this study, anti-HPA-1a sera (NIBSC 03/152) and human monoclonal antibodies (moabs) against HPA-1a (moabs 26.4 and 813) were evaluated using transfected cell lines expressing αIIbβ3, αvβ3 or monomeric cβ3. Results Flow cytometry analyses with well-characterized murine moabs recognizing αIIbβ3, αvβ3, or β3 alone demonstrated that AP3 reacts compound-independently, whereas compound-dependent moabs Gi5 and 23C6 reacted only with complexes. NIBSC 03/152, moabs 26.4, and 813 against HPA-1a reacted like AP3, same results were obtained with monomeric cβ3 in immunoblotting. Antigen capture assay targeting endothelial cells showed anti-HPA-1a reactivity disappearance after cβ3 beads adsorption. Furthermore, in contrast to anti-HPA-1a abs from ICH cases, none of NIBSC 03/152, 26.4, and 813 inhibited tube formation. Conclusion These results suggest that current anti-HPA-1a standard material contains only the anti-β3 subtype. The absence of anti-αvβ3 makes NIBSC 03/152 less suitable as standard to predict the severity of FNAIT.

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