Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (674 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
The degree of antigenic similarity between the tissues of different individuals, which determines the acceptance or rejection of allografts.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Histocompatibilities; Tissue Compatibility; Compatibility, Tissue; Tissue Compatibilities; Immunocompatibility; Immunocompatibilities; Histoincompatibility; Histoincompatibilities.
Where it fits in the MeSH classification
- Broader topics
- Transplantation Immunology
- Narrower topics
- Histocompatibility, Maternal-Fetal
Research landscape
PubMed indexes 7,578 records tagged with the MeSH heading “Histocompatibility” (counts retrieved 2026-10-29). 328 of them (4.3%) were published from 2020 onward, and the busiest period so far is through 1999 with 4,831 records.
Reviews account for 1,079 records (14.2%) and meta-analyses for 11. Randomized controlled trials number 42 (0.6%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 4,831 |
| 2000-2009 | 1,036 |
| 2010-2019 | 1,383 |
| 2020 onward | 328 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 1,079 | 14.2% |
| Meta-analyses | 11 | 0.1% |
| Randomized controlled trials | 42 | 0.6% |
Method: PubMed query "Histocompatibility"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-29.
Reading the evidence in immunology
Immune responses are studied in model organisms, in cells from donors and in patients, and the same pathway can behave differently across these settings. Mouse immune systems differ from human ones in important ways, and blood measurements may not reflect what happens in tissues. Clinical conclusions about immune-mediated disease or immunotherapy come mainly from controlled trials and long-term cohorts. Check the species and tissue studied, whether markers were linked to outcomes patients notice, and the follow-up time.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Maternal Immunological Adaptation During Normal Pregnancy | 2020 | Review article Design not recorded in structured metadata | 503 | cc by PMID 33133091 · DOI · PMC7579415 |
| Upfront haploidentical transplant for acquired severe aplastic anemia: registry-based comparison with matched related transplant | 2017 | Research article Design not recorded in structured metadata | 178 | cc by PMID 28107815 · DOI · PMC5251320 |
| Role of Decidual Natural Killer Cells in Human Pregnancy and Related Pregnancy Complications | 2021 | Review article Design not recorded in structured metadata | 164 | cc by PMID 34512661 · DOI · PMC8426434 |
| Landscapes of HLA Mismatching in Contemporary Unrelated Haematopoietic Cell Transplantation | 2026 | Research article Design not recorded in structured metadata | 0 | cc by PMID 41811229 · DOI · PMC12978212 |
Maternal Immunological Adaptation During Normal Pregnancy [1]
Abstract reading summary — source excerpts
- Opening excerpt
- The risk and severity of specific infections are increased during pregnancy due to a combination of physiological and immunological changes.
- Closing excerpt
- In this review, we describe what is known about the immunological changes that occur during a normal pregnancy.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (87 words)
The risk and severity of specific infections are increased during pregnancy due to a combination of physiological and immunological changes. Characterizing the maternal immune system during pregnancy is important to understand how the maternal immune system maintains tolerance towards the allogeneic fetus. This may also inform strategies to prevent maternal fatalities due to infections and optimize maternal vaccination to best protect the mother-fetus dyad and the infant after birth. In this review, we describe what is known about the immunological changes that occur during a normal pregnancy.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 33133091 · DOI · PMC7579415
Upfront haploidentical transplant for acquired severe aplastic anemia: registry-based comparison with matched related transplant [2]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundHaploidentical donor (HID) hematopoietic stem cell transplantation (HSCT) is an alternative treatment method for severe aplastic anemia (SAA) patients lacking suitable identical donors and those who are refractory to immunosuppressive therapy (IST).
- Closing excerpt
- 5%, P ConclusionsHaploidentical SCT as upfront therapy was an effective and safe option for SAA patients, with favorable outcomes in experienced centers.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (156 words)
BackgroundHaploidentical donor (HID) hematopoietic stem cell transplantation (HSCT) is an alternative treatment method for severe aplastic anemia (SAA) patients lacking suitable identical donors and those who are refractory to immunosuppressive therapy (IST). The current study evaluated the feasibility of upfront haploidentical HSCT in SAA patients.MethodsWe conducted a multicenter study based on a registry database. One hundred fifty-eight SAA patients who underwent upfront transplantation between June 2012 and September 2015 were enrolled.ResultsEighty-nine patients had haploidentical donors (HIDs), and 69 had matched related donors (MRDs) for HSCT. The median times for myeloid engraftment in the HID and MRD cohorts were 12 (range, 9-20) and 11 (range, 8-19) days, with a cumulative incidence of 97.8 and 97.1% (P = 0.528), respectively. HID recipients had an increased cumulative incidence of grades II-IV acute graft-versus-host disease (aGVHD) (30.3 vs. 1.5%, P ConclusionsHaploidentical SCT as upfront therapy was an effective and safe option for SAA patients, with favorable outcomes in experienced centers.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 28107815 · DOI · PMC5251320
Role of Decidual Natural Killer Cells in Human Pregnancy and Related Pregnancy Complications [3]
Abstract reading summary — source excerpts
- Opening excerpt
- Pregnancy is a unique type of immunological process.
- Closing excerpt
- dNK cells could be targets for the treatment of pregnancy complications.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (172 words)
Pregnancy is a unique type of immunological process. Healthy pregnancy is associated with a series of inflammatory events: implantation (inflammation), gestation (anti-inflammation), and parturition (inflammation). As the most abundant leukocytes during pregnancy, natural killer (NK) cells are recruited and activated by ovarian hormones and have pivotal roles throughout pregnancy. During the first trimester, NK cells represent up to 50-70% of decidua lymphocytes. Differently from peripheral-blood NK cells, decidual natural killer (dNK) cells are poorly cytolytic, and they release cytokines/chemokines that induce trophoblast invasion, tissue remodeling, embryonic development, and placentation. NK cells can also shift to a cytotoxic identity and carry out immune defense if infected in utero by pathogens. At late gestation, premature activation of NK cells can lead to a breakdown of tolerance of the maternal-fetal interface and, subsequently, can result in preterm birth. This review is focused on the role of dNK cells in normal pregnancy and pathological pregnancy, including preeclampsia, recurrent spontaneous abortion, endometriosis, and recurrent implantation failure. dNK cells could be targets for the treatment of pregnancy complications.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 34512661 · DOI · PMC8426434
Landscapes of HLA Mismatching in Contemporary Unrelated Haematopoietic Cell Transplantation [4]
Abstract reading summary — source excerpts
- Opening excerpt
- Haematopoietic cell transplantation (HCT) with HLA-mismatched unrelated donors (MMUD) offers access to curative therapy for patients lacking well-matched donors.
- Closing excerpt
- Our study constitutes the first large-scale characterisation of real-world HLA mismatch frequencies in contemporary unrelated HCT, bearing implications for future clinical outcome studies.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (259 words)
Haematopoietic cell transplantation (HCT) with HLA-mismatched unrelated donors (MMUD) offers access to curative therapy for patients lacking well-matched donors. Accumulating evidence suggests that functional matching among allele-mismatched pairs can significantly influence patient outcomes. Therefore, real-world data on mismatch frequencies in MMUD-HCT could provide fundamental information for the assessment of patient risks and donor selection strategies. Here, we analysed HLA matching in 28,376 first unrelated transplants reported to the EBMT Registry with available 6-locus high-resolution typing. Mismatches at each locus were quantified and characterised at the allelic, antigenic and functional (antigen-recognition domain, peptide-binding motif) levels. 25% of the transplants were performed across one (9/10; n = 6053) or more (< 9/10; n = 1013) high-resolution mismatches at the five main HLA loci, a proportion that was markedly higher (43.9%) among transplants performed with post-transplantation cyclophosphamide (PTCy). Median time from diagnosis to transplant was longer for MMUD compared to 10/10 transplants, but this difference decreased over time (14.9 vs. 11.3 months pre-2011, p = 0.003; 8.1 vs. 7.4 months 2021-2022, p = 0.016). Across transplant eras, single class I mismatches were three times more common than class II mismatches. Conversely, matching for HLA-DPB1 increased from 15% pre-2011 to 31% in 2021-2022. The landscapes of allelic mismatches differed markedly between HLA loci. For class II, skewed distributions dominated by frequent combinations result in significantly higher frequencies of functional matching compared to class I in both PTCy and non-PTCy pairs. Our study constitutes the first large-scale characterisation of real-world HLA mismatch frequencies in contemporary unrelated HCT, bearing implications for future clinical outcome studies.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41811229 · DOI · PMC12978212
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Histocompatibility-linked immune response genes [5]
- Research article Evolutionary significance of the HL-A system [6]
- Research article The immune response genes of the major histocompatibility complex [7]
- Research article The immunomodulatory roles of macrophages at the maternal-fetal interface [8]
- Research article The molecular basis of alloreactivity [9]
- Research article Seminal fluid and fertility in women [10]
References
- Abu-Raya B, Michalski C, Sadarangani M, Lavoie PM. Maternal Immunological Adaptation During Normal Pregnancy. . 2020. PMID 33133091 · DOI · PMC7579415
- Xu LP, Jin S, Wang SQ, Xia LH, Bai H, Gao SJ, et al.. Upfront haploidentical transplant for acquired severe aplastic anemia: registry-based comparison with matched related transplant. . 2017. PMID 28107815 · DOI · PMC5251320
- Zhang X, Wei H. Role of Decidual Natural Killer Cells in Human Pregnancy and Related Pregnancy Complications. . 2021. PMID 34512661 · DOI · PMC8426434
- Arrieta-Bolaños E, Bonneville EF, Crivello P, Gedde-Dahl T, Peffault de Latour R, Salmenniemi U, et al.. Landscapes of HLA Mismatching in Contemporary Unrelated Haematopoietic Cell Transplantation. . 2026. PMID 41811229 · DOI · PMC12978212
- Benacerraf B, McDevitt HO. Histocompatibility-linked immune response genes. Science. 1972. PMID 4109878 · DOI
- Bodmer WF. Evolutionary significance of the HL-A system. Nature. 1972. PMID 4113158 · DOI
- Benacerraf B, Germain RN. The immune response genes of the major histocompatibility complex. Immunol Rev. 1978. PMID 75166 · DOI
- Nagamatsu T, Schust DJ. The immunomodulatory roles of macrophages at the maternal-fetal interface. Reprod Sci. 2010. PMID 20065301 · DOI
- Lechler RI, Lombardi G, Batchelor JR, Reinsmoen N, Bach FH. The molecular basis of alloreactivity. Immunol Today. 1990. PMID 2186745 · DOI
- Robertson SA, Sharkey DJ. Seminal fluid and fertility in women. Fertil Steril. 2016. PMID 27485480 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-29.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.