Real-world experience of nintedanib for progressive fibrosing interstitial lung disease in the UK

Background

Nintedanib slows progression of lung function decline in patients with progressive fibrosing (PF) interstitial lung disease (ILD) and was recommended for this indication within the United Kingdom (UK) National Health Service in Scotland in June 2021 and in England, Wales and Northern Ireland in November 2021. To date, there has been no national evaluation of the use of nintedanib for PF-ILD in a real-world setting.

Methods

26 UK centres were invited to take part in a national service evaluation between 17 November 2021 and 30 September 2022. Summary data regarding underlying diagnosis, pulmonary function tests, diagnostic criteria, radiological appearance, concurrent immunosuppressive therapy and drug tolerability were collected via electronic survey.

Results

24 UK prescribing centres responded to the service evaluation invitation. Between 17 November 2021 and 30 September 2022, 1120 patients received a multidisciplinary team recommendation to commence nintedanib for PF-ILD. The most common underlying diagnoses were hypersensitivity pneumonitis (298 out of 1120, 26.6%), connective tissue disease associated ILD (197 out of 1120, 17.6%), rheumatoid arthritis associated ILD (180 out of 1120, 16.0%), idiopathic nonspecific interstitial pneumonia (125 out of 1120, 11.1%) and unclassifiable ILD (100 out of 1120, 8.9%). Of these, 54.4% (609 out of 1120) were receiving concomitant corticosteroids, 355 (31.7%) out of 1120 were receiving concomitant mycophenolate mofetil and 340 (30.3%) out of 1120 were receiving another immunosuppressive/modulatory therapy. Radiological progression of ILD combined with worsening respiratory symptoms was the most common reason for the diagnosis of PF-ILD.

Conclusion

We have demonstrated the use of nintedanib for the treatment of PF-ILD across a broad range of underlying conditions. Nintedanib is frequently co-prescribed alongside immunosuppressive and immunomodulatory therapy. The use of nintedanib for the treatment of PF-ILD has demonstrated acceptable tolerability in a real-world setting.

Health-Related Quality of Life and Disability Among Older New Zealanders With Kidney Failure: A Prospective Study

Background:

Disability is prevalent in individuals with kidney failure and can contribute to significantly reduced quality of life and survival. In older individuals with kidney failure, disability can be caused by a combination of factors, including issues directly related to their kidney disease and/or treatment, including weakness, low energy, and low activity. Few studies have investigated health-related quality of life (HRQoL) as a possible predictor of disability among older individuals experiencing kidney failure.

Objective:

This study aimed to determine if patient-reported HRQoL, and/or other factors at baseline, predicts disability in people with kidney failure, aged ≥65 years, after 12 months of follow-up.

Design:

The DOS65+ study was an accelerated longitudinal cohort design comprising of both cross-sectional and longitudinal components. Participants were eligible if they were aged ≥65 years, had chronic kidney disease stage 5G (CKD 5G) (estimated glomerular filtration rate (eGFR) <15 ml/min/1.73 m²), and had: commenced kidney replacement education, or were on an active conservative pathway, or were newly incident dialysis patients commencing dialysis therapy or prevalent on dialysis.

Setting:

Three New Zealand District Health Board (DHB) nephrology units (Counties Manukau, Hawke’s Bay, and Southern DHB) were involved in the study.

Participants:

Participants were eligible if they were aged ≥65 years, had CKD 5G (eGFR <15 ml/min/1.73 m²), and had: commenced kidney replacement education, or were on an active conservative pathway, or were newly incident dialysis patients commencing dialysis therapy or prevalent on dialysis.

Measurements:

Disability and HRQoL were measured by EQ-5D-3L, a WHO Disability Assessment Schedule (WHODAS) 2.0.

Methods:

Baseline and 12-month data from our longitudinal dialysis outcomes in older New Zealanders’ study were analyzed to determine if HRQoL at baseline predicted disability outcomes 12 months later.

Results:

Of the 223 participants at baseline, 157 participants completed a follow-up interview 12 months later. Individuals with “considerable disability” at baseline had a significantly (86%) higher risk of experiencing “considerable disability” at 12 months compared with those with “lesser/no disability” at baseline. Two thirds of those with  ≥3 comorbidities were experiencing “considerable disability.” In addition, those with problems with EQ-5D-3L self-care, EQ-5D-3L usual activities, and EQ-5D-3L anxiety/depression reported higher rates of disability.

Limitations:

Selection bias is likely to have been an issue in this study as participants were excluded from the follow-up interview if they had an intercurrent illness requiring hospitalization within 2 weeks of the survey interview or if the treating nephrologist judged that the individual’s ability to take part was significantly impaired. Sample size meant there were a limited number of explanatory/confounding variables that could be investigated in the multivariable model.

Conclusions:

EQ-5D-3L mobility and self-care may be useful in predicting subsequent disability for individuals with CKD 5G. Although individuals with kidney failure often experience disability, previous studies have not clearly identified HRQoL or disability as predictors of later disability for individuals with kidney failure. Therefore, we would recommend the assessment of mobility and self-care, in conjunction with existing disabilities in the clinical review and pre-dialysis education of individuals with kidney failure as they approach the need for kidney replacement therapy.

Trial registration: the Australian and New Zealand clinical trials registry: ACTRN12611000024943.

Screening male prisoners for depression and anxiety with the PHQ-9 and GAD-7 at NHS Healthcheck: patterns of symptoms and caseness threshold

BACKGROUND

Screening for depression and anxiety disorders has been proposed in prison populations but little is known about caseness thresholds on commonly used self-report measures in relation to core symptoms, risk factors and symptom patterns.

METHOD

A cross-sectional prevalence survey measured depression and anxiety caseness (threshold scores > 10 and > 15 on PHQ-9 and GAD-7 and diagnostic algorithm on PHQ-9) in 1205 male prisoners aged 35-74 years eligible for an NHS Healthcheck from six English prisons. Caseness scores were compared with the presence or absence of daily core symptoms of depression and generalised anxiety disorder (GAD), demographic, prison and cardiovascular risk factors. Cluster analysis was applied to PHQ-9 and GAD-7 items in prisoners scoring > 10 on PHQ-9.

RESULTS

453(37.6%) and 249(20.7%) prisoners scored > 10 and > 15 respectively on PHQ-9; 216 (17.9%) had a depressive episode on the PHQ-9 algorithm; 378(31.4%) and 217(18.0%) scored > 10 and > 15 on GAD-7 respectively. Daily core items for depression were scored in 232(56.2%) and 139(74.3%) prisoners reaching > 10 and > 15 respectively on PHQ-9; daily core anxiety items in 282(74.9%) and 179(96.3%) reaching > 10 and > 15 on GAD-7. Young age, prison and previous high alcohol intake were associated with > 15 on the PHQ-9. Cluster analysis showed a cluster with core symptoms of depression, slowness, restlessness, suicidality, poor concentration, irritability or fear. Altered appetite, poor sleep, lack of energy, guilt or worthlessness belonged to other clusters and may not be indicative of depression.

CONCLUSIONS

In male prisoners > 35 years, a score of > 10 on the PHQ-9 over diagnoses depressive episodes but a score of > 10 on the GAD-7 may detect cases of GAD more efficiently. Further research utilising standardised psychiatric interviews is required to determine whether the diagnostic algorithm, a higher cut-off on the PHQ-9 or the profile of symptoms on the PHQ-9 and GAD-7 used singly or in combination may be used to screen depressive episodes efficiently in prisoners.

NHS Health Check Programme: a qualitative study of prison experience

BACKGROUND

NHS Health Checks began in England in 2009 and were subsequently introduced into English prisons. Uptake has been patchy and there is limited understanding about factors that may limit or enhance uptake in prison settings. Uptake of this programme is a key policy in reducing the risk of cardiovascular disease and death in these settings.

METHOD

Semi-structured focus groups were conducted with groups of prisoners (attendees and non-attendees to the health check), prison healthcare staff, custodial staff and ex-prisoners (n = 50). Participants were asked about their awareness and experiences of the NHS Health Check Programme in prison.

RESULTS

All groups highlighted barriers for not attending a health check appointment, such as poor accessibility to the healthcare department, stigma and fear. The majority of participants expressed a lack of awareness and discussed common misconceptions regarding the health check programme. Methods of increasing the uptake of health checks through group-based approaches and accessibility to healthcare were suggested.

CONCLUSIONS

This study reports on prisoner, staff and ex-prisoner perspectives on the implementation of NHS Health Checks within a restrictive prison environment. These findings have potentially substantial implications for successful delivery of care within offender healthcare services.

Cardiovascular risk profiles and the uptake of the NHS Healthcheck programme in male prisoners in six UK prisons: an observational cross-sectional survey

INTRODUCTION

Half of all deaths in custody are due to natural causes, the most common being cardiovascular disease (CVD). National Health Service Healthchecks should be available to all eligible prisoners; it is not clear who receives them. Mental health issues are common in prisoners and may affect how healthcare interventions should be delivered. Current policy is to offer Healthchecks to those serving over 2 years in prison.

OBJECTIVES, METHODS, SETTING AND DESIGN

An observational cross-sectional survey in six male prisons in England between September 2017 and January 2019 in prisoners aged 35-74 to identify who was eligible for a Healthcheck and compare CVD risk data with those that were not, and factors associated with uptake.

OUTCOME MEASURES

Characteristics of those accepting a Healthcheck were compared with those declining. Assessments of anxiety and depression were compared with CVD risk factors.

RESULTS

1207 prisoners completed a Healthcheck. 21.8% of prisoners were ineligible due to existing comorbidities. 76.4% of those invited took up a Healthcheck, and of those, 12.1% were found to have new significant CVD comorbidity. CVD risk was similar to community levels but this population was 10 years younger. Definite case-level depression or anxiety was present in 20.7% and 18.0%, respectively, of participants. An association was found between ethnicity and those invited (p=0.023, φ=0.1) and accepting (p=0.008, φ=0.1) a Healthcheck. 9.7% of prisoners serving less than 2 years had CVD risk scores of 10% or more, and had similar CVD risk profiles but much higher levels of anxiety (p<0.001, φ=0.2) or depression (p=0.009, φ=0.2) than those serving 2 years or more.

CONCLUSION

Cardiovascular risk was comparable with community rates and in some prisons, much higher. Rates of anxiety and depression were high. The national policy for selecting prisoners for Healthchecks may leave many high-risk prisoners without appropriate cardiovascular preventative assessments.

A review of mentoring deaf and hard-of-hearing scholars

Diversification of the scientific workforce usually focuses on recruitment and retention of women and underrepresented racial and ethnic minorities but often overlooks deaf and hard-of hearing (D/HH) persons. Usually classified as a disability group, such persons are often members of their own sociocultural linguistic minority and deserve unique support. For them, access to technical and social information is often hindered by communication- and/or language-centered barriers, but securing and using communication access services is just a start. Critical aspects of training D/HH scientists as part of a diversified workforce necessitates: (a) educating hearing persons in cross-cultural dynamics pertaining to deafness, sign language, and Deaf culture; (b) ensuring access to formal and incidental information to support development of professional soft skills; and (c) understanding that institutional infrastructure change may be necessary to ensure success. Mentorship and training programs that implement these criteria are now creating a new generation of D/HH scientists.

Comparison of 24-hour urine and 24-hour diet recall for estimating dietary sodium intake in populations: A systematic review and meta-analysis

This systematic literature review and meta-analysis examined whether 24-hour diet recall is a valid way to measure mean population sodium intake compared with the gold standard 24-hour urinary assessment. The authors searched electronic databases MEDLINE, Embase, and Scopus using pre-defined terms. Studies were eligible for inclusion if they assessed adult humans in free-living settings, and if they included group means for 24-hour diet recall and 24-hour urinary collection of sodium intake in the same participants. Studies that included populations with an active disease state that might interfere with normal sodium metabolism were excluded. Results of 28 studies are included in the meta-analysis. Overall, 24-hour diet recall underestimated population mean sodium intake by an average of 607 mg per day compared to the 24-hour urine collection. The difference between measures from 24-hour urine and 24-hour diet recall was smaller in studies conducted in high-income countries, in studies where multiple-pass methods of 24-hour diet recall were reported and where urine was validated for completeness. Higher quality studies also reported smaller differences between measures than lower quality studies. Monitoring of population sodium intake with 24-hour urinary excretion remains the most accurate method of assessment. Twenty-four-hour diet recall tends to underestimate intake, although high-quality 24-hour diet recall improves accuracy, and may be used if 24-hour urine is not feasible.

Dependence on place: A source of autonomy in later life for older Māori

Attachment to place is an important component of ageing. Although the importance of place for older people's well-being is known, the ways in which different conceptions of place and expectations for what later life may hold depend upon cultural beliefs, values, and expectations is underexplored. This study examined the ways that place influences experiences of ageing for older Māori in New Zealand. Eight interviews with older Māori were analysed thematically alongside field notes from a research visit. Attachment to place provided the foundation for experiences of ageing for older Māori. Through their connection to place, the participants drew on a comforting and comfortable dependence on land and family to enable autonomy in later life. Rather than seeking to maintain independence in terms of avoiding reliance on others, older Māori conceptualised older age through autonomy and freedom to live in accordance with Māori values encapsulated by whakawhanaungatanga. A good old age depended on balancing competing demands of living in wider society with attachment to place and Māori identity in later life.

Nuclear waste viewed in a new light; a synchrotron study of uranium encapsulated in grout

How do you characterise the contents of a sealed nuclear waste package without breaking it open? This question is important when the contained corrosion products are potentially reactive with air and radioactive. Synchrotron X-rays have been used to perform micro-scale in-situ observation and characterisation of uranium encapsulated in grout; a simulation for a typical intermediate level waste storage packet. X-ray tomography and X-ray powder diffraction generated both qualitative and quantitative data from a grout-encapsulated uranium sample before, and after, deliberately constrained H2 corrosion. Tomographic reconstructions provided a means of assessing the extent, rates and character of the corrosion reactions by comparing the relative densities between the materials and the volume of reaction products. The oxidation of uranium in grout was found to follow the anoxic U+H2O oxidation regime, and the pore network within the grout was observed to influence the growth of uranium hydride sites across the metal surface. Powder diffraction analysis identified the corrosion products as UO2 and UH3, and permitted measurement of corrosion-induced strain. Together, X-ray tomography and diffraction provide means of accurately determining the types and extent of uranium corrosion occurring, thereby offering a future tool for isolating and studying the reactions occurring in real full-scale waste package systems.

The primate lentiviral receptor Bonzo/STRL33 is coordinately regulated with CCR5 and its expression pattern is conserved between human and mouse

Chemokines play necessary and important roles in regulating the trafficking of lymphocytes to intra- or interlymphoid tissues as well as to sites of inflammation. The complex migratory patterns of lymphoid lineage cells is governed by subset-specific expression of chemokine receptors and their access to specific ligands. Several chemokine receptors and chemokine receptor-like orphan receptors also serve, in conjunction with CD4, as coreceptors for infection by human and simian immunodeficiency viruses (HIV and SIV). Here we show that the expression pattern of Bonzo/STRL33, an orphan SIV/HIV coreceptor, is highly restricted to the memory subset of T cells and is up-regulated upon stimulation of these cells with IL-2 or IL-15. Both the pattern and the regulation of Bonzo expression closely paralleled that of CC family chemokine receptors CCR5 or CCR6 and inversely correlated with CXCR4 expression. However, in striking contrast to CCR5, Bonzo expression was not down-modulated by PMA or mitogen stimulation of T cells. Targeted replacement of the Bonzo gene with a gene encoding green fluorescent protein in mice revealed that the expression and cytokine regulation of mouse Bonzo are comparable to those of its human counterpart. The similar expression and regulation patterns of Bonzo and the HIV coreceptor CCR5 may have implications for understanding the role of HIV/SIV receptors in viral evolution and pathogenesis.

Monoclonal antibodies specific for beta 7 integrin and mucosal addressin cell adhesion molecule-1 (MAdCAM-1) reduce inflammation in the colon of scid mice reconstituted with CD45RBhigh CD4+ T cells

Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is an adhesion protein expressed on endothelium in mucosal tissues that has been shown to play an important role in the selective homing of lymphocytes to intestinal mucosa and associated lymphoid tissue. To determine whether MAdCAM-1 or its ligand alpha 4 beta 7 would be appropriate targets for therapeutic intervention in gut-associated inflammation, we tested the ability of rat mAbs specific for beta 7 integrin and MAdCAM-1 to inhibit chronic colonic inflammation in scid mice reconstituted with CD4+ T cells enriched for the CD45RBhigh subpopulation. Abs specific for beta 7 and MAdCAM-1 blocked recruitment of lymphocytes to the colitic colon, and more importantly, these Abs significantly reduced the severity of colonic inflammatory disease in this animal model. Therefore, the adhesive interactions mediated by alpha 4 beta 7 and MAdCAM are intimately involved in leukocyte recruitment to gut in chronic inflammatory disease and may be relevant therapeutic targets for patients with inflammatory bowel disease.

Monoclonal antibodies specific for beta 7 integrin and mucosal addressin cell adhesion molecule-1 (MAdCAM-1) reduce inflammation in the colon of scid mice reconstituted with CD45RBhigh CD4+ T cells

Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is an adhesion protein expressed on endothelium in mucosal tissues that has been shown to play an important role in the selective homing of lymphocytes to intestinal mucosa and associated lymphoid tissue. To determine whether MAdCAM-1 or its ligand alpha 4 beta 7 would be appropriate targets for therapeutic intervention in gut-associated inflammation, we tested the ability of rat mAbs specific for beta 7 integrin and MAdCAM-1 to inhibit chronic colonic inflammation in scid mice reconstituted with CD4+ T cells enriched for the CD45RBhigh subpopulation. Abs specific for beta 7 and MAdCAM-1 blocked recruitment of lymphocytes to the colitic colon, and more importantly, these Abs significantly reduced the severity of colonic inflammatory disease in this animal model. Therefore, the adhesive interactions mediated by alpha 4 beta 7 and MAdCAM are intimately involved in leukocyte recruitment to gut in chronic inflammatory disease and may be relevant therapeutic targets for patients with inflammatory bowel disease.

Human circulating specific antibody-forming cells after systemic and mucosal immunizations: differential homing commitments and cell surface differentiation markers

Circulating spontaneous antibody-secreting cells (ASC) induced by mucosal and systemic immunizations in human volunteers have been characterized with respect to differentiation stage and homing commitments. Irrespective of the immunization route, the large majority of ASC co-expressed CD19 and HLA-DR, which are normally lost during the transition of plasmablasts to plasmocytes, as well as CD38, a marker of activated B cell blasts, expressed also by plasmocytes. However, these cells expressed neither CD28, a molecule acquired by plasmocytes, nor CD22 and CD37, which are lost during the transition of plasmablasts to plasmocytes. Therefore, the large majority of ASC found in peripheral blood after oral and parenteral immunizations are terminally differentiated B cells, but not fully differentiated plasmocytes. As a whole, the mucosally derived ASC population seemed to be more homogenously differentiated. CD25 was detected on few ASC, whereas ASC expressing CD71 were more numerous, especially among systemically derived ASC. Almost all ASC expressed the adhesion molecules CD44 and alpha 4-integrins, irrespective of immunization route. However, virtually all systemically derived ASC expressed L-selectin, recognizing the peripheral lymph node addressin, whereas only a minority of mucosally induced blood ASC expressed L-selectin. These studies are the first to demonstrate in humans that circulating precursors of mucosal B cell immunoblasts utilize organ-specific recognition mechanisms distinct from those of corresponding systemic B cells and appear to be more advanced in the B lineage maturation pathway. Specialization of receptor expression could explain both the unification of immune responses in diverse mucosal sites and the physiologic segregation of mucosal from non-mucosal immune mechanisms in humans.

Neutrophil aggregation is beta 2-integrin- and L-selectin-dependent in blood and isolated cells

Neutrophil aggregation in response to formyl peptide was analyzed in blood and isolated cells by fluorescence flow cytometry. The isolated leukocyte aggregates and the leukocytes in blood were identified with the vital nucleic acid stain LDS-751. This method enabled us to discriminate nucleated cells from other blood cells and to detect granulocyte aggregates without isolation or E lysis. Cells isolated in the absence of endotoxin retained the characteristics of cells in blood and exhibited similar aggregation kinetics and dose-response to formyl peptide. We show that it is possible to analyze epitope expression in blood with homogeneous flow cytometric assays and that carefully isolated neutrophils retain the expression characteristics of those in blood. The expression of CD18 was at its lowest levels in unstimulated cells, while the rate of formyl peptide stimulated aggregation was most rapid in these cells. Aggregation in isolated cells as well as blood preceded an increase in receptor expression. After stimulation, L-selectin expression decreased in both blood and isolated cells over a time frame similar to disaggregation. The aggregation response in blood was blocked by pretreatment with antibody to CD18 over a concentration range consistent with the amount of antibody bound. Aggregation was also blocked in isolated cells and blood by antibodies DREG-200 and DREG-56 to L-selectin, but not by isotype controls or anti-LFA-1. The results are discussed in terms of the roles of adhesive receptor expression and recognition in neutrophil aggregation. The methods validated here permit linkage between isolated cells and in vivo studies.

Neutrophil aggregation is beta 2-integrin- and L-selectin-dependent in blood and isolated cells

Neutrophil aggregation in response to formyl peptide was analyzed in blood and isolated cells by fluorescence flow cytometry. The isolated leukocyte aggregates and the leukocytes in blood were identified with the vital nucleic acid stain LDS-751. This method enabled us to discriminate nucleated cells from other blood cells and to detect granulocyte aggregates without isolation or E lysis. Cells isolated in the absence of endotoxin retained the characteristics of cells in blood and exhibited similar aggregation kinetics and dose-response to formyl peptide. We show that it is possible to analyze epitope expression in blood with homogeneous flow cytometric assays and that carefully isolated neutrophils retain the expression characteristics of those in blood. The expression of CD18 was at its lowest levels in unstimulated cells, while the rate of formyl peptide stimulated aggregation was most rapid in these cells. Aggregation in isolated cells as well as blood preceded an increase in receptor expression. After stimulation, L-selectin expression decreased in both blood and isolated cells over a time frame similar to disaggregation. The aggregation response in blood was blocked by pretreatment with antibody to CD18 over a concentration range consistent with the amount of antibody bound. Aggregation was also blocked in isolated cells and blood by antibodies DREG-200 and DREG-56 to L-selectin, but not by isotype controls or anti-LFA-1. The results are discussed in terms of the roles of adhesive receptor expression and recognition in neutrophil aggregation. The methods validated here permit linkage between isolated cells and in vivo studies.

Chemotactic factors regulate lectin adhesion molecule 1 (LECAM-1)-dependent neutrophil adhesion to cytokine-stimulated endothelial cells in vitro

Monoclonal antibodies recognizing CD18, CD11a, CD11b, and neutrophil lectin adhesion molecule 1 (LECAM-1), i.e., the human homologue of the murine MEL-14 antigen, were used to assess the relative contribution of these glycoproteins to neutrophil-endothelial adhesion. Under static conditions, the adhesion of neutrophils to IL-1-stimulated human umbilical vein endothelial cell (HUVEC) monolayers was inhibited by antibodies to CD18, CD11a, and the neutrophil LECAM-1, and the effect of combining anti-LECAM-1 and anti-CD11a was almost additive. Under flow at a wall shear stress 1.85 dyn/cm2, a condition where CD18-dependent adhesion is minimal, anti-LECAM-1 inhibited adhesion by greater than 50%. Chemotactic stimulation of neutrophils induced a rapid loss of LECAM-1 from the neutrophil surface, and the level of neutrophil surface LECAM-1 was closely correlated with adhesion under flow. Neutrophils contacting the activated endothelial cells for 30 min lost much of their surface LECAM-1, a phenomenon induced by a soluble factor or factors released into the medium by the stimulated monolayers, and a high percentage migrated through the HUVEC monolayer. This migration was almost completely inhibited by anti-CD18, but was unaffected by antibodies to neutrophil LECAM-1. These results support the concept that LECAM-1 is a neutrophil adhesion molecule that participates in the adherence of unstimulated neutrophils to cytokine-stimulated endothelial cells under conditions of flow, and is then lost from the neutrophil surface coincident with the engagement of CD18-dependent mechanisms leading to transendothelial migration.

T cell maturation: thymocyte and thymus migrant subpopulations defined with monoclonal antibodies to MHC region antigens

The maturation sequences of thymocytes is known to some extent: A generative layer of subcapsular large lymphoblasts gives rise to a major population of small cortical thymocytes and a minor population of midsize medullary thymocytes. The relative contribution of these three populations to the peripheral T cell populations is not yet known. In this study, subcapsular lymphoblasts, cortical small cells, medullary cells, and thymic emigrant cells have all been analyzed by immunofluorescence for expression of the antigens H-2D, I-A, H-2K, and TL. H-2D is expressed brightly on all subcapsular large cells, dimly on cortical small cells, and brightly on all migrants, cortisone-resistant thymocytes (CRT), and peripheral T cells. I-A can be detected at low levels on 30 to 50% of cells in all the thymic subpopulations, and on 30 to 50% of migrants and peripheral T cells. Fifty to 80% of small cortical cells do not express detectable H-2K, but all the other subpopulations, both inside and outside the thymus, stain uniformly quite brightly. TL3 is expressed on 70 to 80% of subcapsular and cortical thymocytes, 30 to 40% of CRT, is undetectable on migrants but can be seen at low levels on 10 to 20% of spleen and lymph node T cells. The possibility that some or all of these antigens represent stable markers of separate lineages rather than unstable, stage-specific markers is discussed.

T cell maturation: thymocyte and thymus migrant subpopulations defined with monoclonal antibodies to MHC region antigens

The maturation sequences of thymocytes is known to some extent: A generative layer of subcapsular large lymphoblasts gives rise to a major population of small cortical thymocytes and a minor population of midsize medullary thymocytes. The relative contribution of these three populations to the peripheral T cell populations is not yet known. In this study, subcapsular lymphoblasts, cortical small cells, medullary cells, and thymic emigrant cells have all been analyzed by immunofluorescence for expression of the antigens H-2D, I-A, H-2K, and TL. H-2D is expressed brightly on all subcapsular large cells, dimly on cortical small cells, and brightly on all migrants, cortisone-resistant thymocytes (CRT), and peripheral T cells. I-A can be detected at low levels on 30 to 50% of cells in all the thymic subpopulations, and on 30 to 50% of migrants and peripheral T cells. Fifty to 80% of small cortical cells do not express detectable H-2K, but all the other subpopulations, both inside and outside the thymus, stain uniformly quite brightly. TL3 is expressed on 70 to 80% of subcapsular and cortical thymocytes, 30 to 40% of CRT, is undetectable on migrants but can be seen at low levels on 10 to 20% of spleen and lymph node T cells. The possibility that some or all of these antigens represent stable markers of separate lineages rather than unstable, stage-specific markers is discussed.