Bare lymphocyte syndrome type II

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Bare lymphocyte syndrome type II
Other namesHLA class 2-negative severe combined immunodeficiency, HLA Class 2-Negative
Autosomal recessive - en.svg
Bare lymphocyte syndrome 2 is autosomal recessive in inheritance
Specialty Immunology, pediatrics, endocrinology   OOjs UI icon edit-ltr-progressive.svg
Symptoms Neutropenia [1]
CausesAbsence of human leukocyte antigen class II expression [1]
Diagnostic method Genetic test [1]
Medication Bone marrow transplant [2]

Bare lymphocyte syndrome type II (BLS II) is a rare recessive genetic condition in which a group of genes called major histocompatibility complex class II (MHC class II) are not expressed. [3] [4]

Contents

Symptoms and signs

Among the signs and symptoms that Bare lymphocyte syndrome type II exhibits are the following: [1] [5]

Cause

The genetic cause of Bare lymphocyte syndrome type II is due to mutations in any of the following genes: [5]

Mechanism

MHC Class 2 MHC Class 2.svg
MHC Class 2

Major histocompatibility complex class II proteins are important because under normal function they have important responsibility in the human body's immune system response. MHC II proteins present exogenous antigens that activate CD4+ T-lymphocytes, immune cells that are responsible for activating other immune cells like CD8+ T-lymphocytes and macrophages. [10] MHC II proteins are also important for positive and negative selection in the thymus because they present antigens to immature T-cells, allowing the T cells to differentiate into proper functioning CD4+ T-lymphocytes. This may explain why patients with BLS II display decreased levels of CD4+ T-lymphocytes in their blood. [11]

The basis for BLSII is not due to defects in the MHC II genes themselves, it is the result of mutations in genes that code for proteins, transcription factors that normally regulate the expression of the MHC II genes. One of the several proteins that are required to switch on MHC II genes in various cells types is absent. [5]

Diagnosis

The diagnosis for Bare lymphocyte syndrome type II can be done via genetic testing [12] A blood test could indicate decreased CD4+ T-cells(T-helper lymphocyte), as well as serum immunoglobulin [2]

Management

Bone marrow KM Transplantat.JPEG
Bone marrow

In terms of treatment for major histocompatibility complex class II deficiency(Bare lymphocyte syndrome type II), one finds that according to Matheux, et al. a possible treatment for this condition might be found in cellular and gene therapy [13] The prognosis is poor (without treatment) in early childhood for this condition; [14] [2] additional treatment options include anti-microbial prophylaxis prior to bone marrow transplant [2] [15]

See also

Related Research Articles

Histocompatibility, or tissue compatibility, is the property of having the same, or sufficiently similar, alleles of a set of genes called human leukocyte antigens (HLA), or major histocompatibility complex (MHC). Each individual expresses many unique HLA proteins on the surface of their cells, which signal to the immune system whether a cell is part of the self or an invading organism. T cells recognize foreign HLA molecules and trigger an immune response to destroy the foreign cells. Histocompatibility testing is most relevant for topics related to whole organ, tissue, or stem cell transplants, where the similarity or difference between the donor's HLA alleles and the recipient's triggers the immune system to reject the transplant. The wide variety of potential HLA alleles lead to unique combinations in individuals and make matching difficult.

<span class="mw-page-title-main">Major histocompatibility complex</span> Cell surface proteins, part of the acquired immune system

The major histocompatibility complex (MHC) is a large locus on vertebrate DNA containing a set of closely linked polymorphic genes that code for cell surface proteins essential for the adaptive immune system. These cell surface proteins are called MHC molecules.

<span class="mw-page-title-main">Human leukocyte antigen</span> Genes on human chromosome 6

The human leukocyte antigen (HLA) system or complex of genes on chromosome 6 in humans which encode cell-surface proteins responsible for regulation of the immune system. The HLA system is also known as the human version of the major histocompatibility complex (MHC) found in many animals.

A class II gene is a type of gene that codes for a protein. Class II genes are transcribed by RNAP II.

<span class="mw-page-title-main">Chromosome 6</span> Human chromosome

Chromosome 6 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 6 spans more than 172 million base pairs and represents between 5.5 and 6% of the total DNA in cells. It contains the major histocompatibility complex, which contains over 100 genes related to the immune response, and plays a vital role in organ transplantation.

<span class="mw-page-title-main">HLA-DRA</span> Protein-coding gene in the species Homo sapiens

HLA class II histocompatibility antigen, DR alpha chain is a protein that in humans is encoded by the HLA-DRA gene. HLA-DRA encodes the alpha subunit of HLA-DR. Unlike the alpha chains of other Human MHC class II molecules, the alpha subunit is practically invariable. However it can pair with, in any individual, the beta chain from 3 different DR beta loci, DRB1, and two of any DRB3, DRB4, or DRB5 alleles. Thus there is the potential that any given individual can form 4 different HLA-DR isoforms.

<span class="mw-page-title-main">Bare lymphocyte syndrome</span> Medical condition

Bare lymphocyte syndrome is a condition caused by mutations in certain genes of the major histocompatibility complex or involved with the processing and presentation of MHC molecules. It is a form of severe combined immunodeficiency.

<span class="mw-page-title-main">MHC class II</span> Protein of the immune system

MHC Class II molecules are a class of major histocompatibility complex (MHC) molecules normally found only on professional antigen-presenting cells such as dendritic cells, macrophages, some endothelial cells, thymic epithelial cells, and B cells. These cells are important in initiating immune responses.

<span class="mw-page-title-main">CIITA</span> Protein-coding gene in humans

CIITA is a human gene which encodes a protein called the class II, major histocompatibility complex, transactivator. Mutations in this gene are responsible for the bare lymphocyte syndrome in which the immune system is severely compromised and cannot effectively fight infection. Chromosomal rearrangement of CIITA is involved in the pathogenesis of Hodgkin lymphoma and primary mediastinal B cell lymphoma.

<span class="mw-page-title-main">HLA-DRB4</span> Protein-coding gene in the species Homo sapiens

Major histocompatibility complex, class II, DR beta 4, also known as HLA-DRB4, is a human gene.

<span class="mw-page-title-main">Major histocompatibility complex, class II, DQ alpha 1</span> Protein-coding gene in the species Homo sapiens

Major histocompatibility complex, class II, DQ alpha 1, also known as HLA-DQA1, is a human gene present on short arm of chromosome 6 (6p21.3) and also denotes the genetic locus which contains this gene. The protein encoded by this gene is one of two proteins that are required to form the DQ heterodimer, a cell surface receptor essential to the function of the immune system.

<span class="mw-page-title-main">HLA-DPB1</span> Protein-coding gene in the species Homo sapiens

HLA class II histocompatibility antigen, DP(W2) beta chain is a protein that in humans is encoded by the HLA-DPB1 gene.

<span class="mw-page-title-main">HLA-DMB</span> Protein-coding gene in the species Homo sapiens

HLA class II histocompatibility antigen, DM beta chain is a protein that in humans is encoded by the HLA-DMB gene.

<span class="mw-page-title-main">HLA-DMA</span> Protein-coding gene in the species Homo sapiens

HLA class II histocompatibility antigen, DM alpha chain is a protein that in humans is encoded by the HLA-DMA gene.

<span class="mw-page-title-main">RFX5</span> Protein-coding gene in the species Homo sapiens

DNA-binding protein RFX5 is a protein that in humans is encoded by the RFX5 gene.

<span class="mw-page-title-main">HLA-DOA</span> Protein-coding gene in the species Homo sapiens

HLA class II histocompatibility antigen, DO alpha chain is a protein that in humans is encoded by the HLA-DOA gene.

<span class="mw-page-title-main">HLA-DOB</span> Protein-coding gene in the species Homo sapiens

HLA class II histocompatibility antigen, DO beta chain is a protein that in humans is encoded by the HLA-DOB gene.

<span class="mw-page-title-main">RFXANK</span> Protein-coding gene in the species Homo sapiens

DNA-binding protein RFXANK is a protein that in humans is encoded by the RFXANK gene.

<span class="mw-page-title-main">RFXAP</span> Protein-coding gene in the species Homo sapiens

Regulatory factor X-associated protein is a protein that in humans is encoded by the RFXAP gene.

<span class="mw-page-title-main">HLA-DQB2</span> Protein-coding gene in the species Homo sapiens

HLA class II histocompatibility antigen, DX beta chain is a protein that in humans is encoded by the HLA-DQB2 gene.

References

  1. 1 2 3 4 "Bare lymphocyte syndrome 2 | Genetic and Rare Diseases Information Center (GARD) – an NCATS Program". rarediseases.info.nih.gov. Archived from the original on 2021-03-18. Retrieved 2017-07-28.
  2. 1 2 3 4 al.], Stephan Strobel ... [et; Smith, Peter K. (2006). Paediatrics and Child Health the Great Ormond Street Handbook. London: Manson Pub. p. 465. ISBN   9781840765625 . Retrieved 28 July 2017.
  3. ↑ "OMIM Entry - # 209920 - BARE LYMPHOCYTE SYNDROME, TYPE II". omim.org. Retrieved 2017-07-13.
  4. ↑ Reference, Genetics Home. "bare lymphocyte syndrome type II". Genetics Home Reference. Retrieved 2017-07-13.
  5. 1 2 3 "SCID due to absent class II HLA antigens (Concept Id: C0242583) - MedGen - NCBI". www.ncbi.nlm.nih.gov. Retrieved 2017-07-28.
  6. ↑ Reference, Genetics Home. "CIITA gene". Genetics Home Reference. Retrieved 2017-07-28.
  7. ↑ Reference, Genetics Home. "RFX5 gene". Genetics Home Reference. Retrieved 2017-07-28.
  8. ↑ Reference, Genetics Home. "RFXANK gene". Genetics Home Reference. Retrieved 2017-07-28.
  9. ↑ Reference, Genetics Home. "RFXAP gene". Genetics Home Reference. Retrieved 2017-07-28.
  10. ↑ Reith, Walter; Picard, Capucine (2016). "Major Histocompatibility Complex Class II Deficiency". Academic Press. 5: 378–390. Retrieved 4 December 2020.
  11. ↑ DeSandro, Angela; Nagarajan, Uma; Boss, Jeremy (September 2017). "Associations and Interactions between Bare Lymphocyte Syndrome Factors". Molecular and Cellular Biology. 20 (17): 6587–6599. doi: 10.1128/mcb.20.17.6587-6599.2000 . PMC   86141 . PMID   10938133.
  12. ↑ "Bare lymphocyte syndrome type 2, complementation group A - Conditions - GTR - NCBI". www.ncbi.nlm.nih.gov. Retrieved 2017-07-28.
  13. ↑ Matheux, Franck; Villard, Jean (June 2004). "Cellular and gene therapy for major histocompatibility complex class II deficiency". News in Physiological Sciences. 19 (3): 154–158. doi:10.1152/nips.01462.2003. ISSN   0886-1714. PMID   15143213.
  14. ↑ RESERVED, INSERM US14 -- ALL RIGHTS. "Orphanet: Immunodeficiency by defective expression of HLA class 2". www.orpha.net. Retrieved 2017-07-28.{{cite web}}: CS1 maint: numeric names: authors list (link)
  15. ↑ Bratzler, Dale W.; Dellinger, E. Patchen; Olsen, Keith M.; Perl, Trish M.; Auwaerter, Paul G.; Bolon, Maureen K.; Fish, Douglas N.; Napolitano, Lena M.; Sawyer, Robert G. (February 2013). "Clinical practice guidelines for antimicrobial prophylaxis in surgery" (PDF). Surgical Infections. 14 (1): 73–156. doi:10.1089/sur.2013.9999. hdl: 2027.42/140217 . ISSN   1557-8674. PMID   23461695.subscription needed

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