Phenotypical characterization of cells in the thoracic duct of patients with and without systemic inflammatory response syndrome and multiple organ failure

Monocytes carrying GFAP detect glioma, brain metastasis and ischaemic stroke, and predict glioblastoma survival

Diagnosis and monitoring of primary brain tumours, brain metastasis and acute ischaemic stroke all require invasive, burdensome and costly diagnostics, frequently lacking adequate sensitivity, particularly during disease monitoring. Monocytes are known to migrate to damaged tissues, where they act as tissue macrophages, continuously scavenging, phagocytizing and digesting apoptotic cells and other tissue debris. We hypothesize that upon completion of their tissue-cleaning task, these tissue macrophages might migrate via the lymph system to the bloodstream, where they can be detected and evaluated for their phagolysosomal contents. We discovered a blood monocyte subpopulation carrying the brain-specific glial fibrillary acidic protein in glioma patients and in patients with brain metastasis and evaluated the diagnostic potential of this finding. Blood samples were collected in a cross-sectional study before or during surgery from adult patients with brain lesions suspected of glioma. Together with blood samples from healthy controls, these samples were flowing cytometrically evaluated for intracellular glial fibrillary acidic protein in monocyte subsets. Acute ischaemic stroke patients were tested at multiple time points after onset to evaluate the presence of glial fibrillary acidic protein-carrying monocytes in other forms of brain tissue damage. Clinical data were collected retrospectively. High-grade gliomas (N = 145), brain metastasis (N = 21) and large stroke patients (>100 cm³) (N = 3 versus 6; multiple time points) had significantly increased frequencies of glial fibrillary acidic protein+CD16+ monocytes compared to healthy controls. Based on both a training and validation set, a cut-off value of 0.6% glial fibrillary acidic protein+CD16+ monocytes was established, with 81% sensitivity (95% CI 75–87%) and 85% specificity (95% CI 80–90%) for brain lesion detection. Acute ischaemic strokes of >100 cm³ reached >0.6% of glial fibrillary acidic protein+CD16+ monocytes within the first 2–8 h after hospitalization and subsided within 48 h. Glioblastoma patients with >20% glial fibrillary acidic protein+CD16+ non-classical monocytes had a significantly shorter median overall survival (8.1 versus 12.1 months). Our results and the available literature, support the hypothesis of a tissue-origin of these glial fibrillary acidic protein-carrying monocytes. Blood monocytes carrying glial fibrillary acidic protein have a high sensitivity and specificity for the detection of brain lesions and for glioblastoma patients with a decreased overall survival. Furthermore, their very rapid response to acute tissue damage identifies large areas of ischaemic tissue damage within 8 h after an ischaemic event. These studies are the first to report the clinical applicability for brain tissue damage detection through a minimally invasive diagnostic method, based on blood monocytes and not serum markers, with direct consequences for disease monitoring in future (therapeutic) studies and clinical decision making in glioma and acute ischaemic stroke patients.

The Identity of Human Tissue-Emigrant CD8+ T Cells

Lymphocyte migration is essential for adaptive immune surveillance. However, our current understanding of this process is rudimentary, because most human studies have been restricted to immunological analyses of blood and various tissues. To address this knowledge gap, we used an integrated approach to characterize tissue-emigrant lineages in thoracic duct lymph (TDL). The most prevalent immune cells in human and non-human primate efferent lymph were T cells. Cytolytic CD8⁺ T cell subsets with effector-like epigenetic and transcriptional signatures were clonotypically skewed and selectively confined to the intravascular circulation, whereas non-cytolytic CD8⁺ T cell subsets with stem-like epigenetic and transcriptional signatures predominated in tissues and TDL. Moreover, these anatomically distinct gene expression profiles were recapitulated within individual clonotypes, suggesting parallel differentiation programs independent of the expressed antigen receptor. Our collective dataset provides an atlas of the migratory immune system and defines the nature of tissue-emigrant CD8⁺ T cells that recirculate via TDL.

Lymphatic endothelial cells of the lymph node

The influx and efflux of cells and antigens to and from the draining lymph nodes largely take place through the subcapsular, cortical and medullary sinus systems. Recent analyses in mice and humans have revealed unexpected diversity in the lymphatic endothelial cells, which form the distinct regions of the sinuses. As a semipermeable barrier, the lymphatic endothelial cells regulate the sorting of lymph-borne antigens to the lymph node parenchyma and can themselves serve as antigen-presenting cells. The leukocytes entering the lymph node via the sinus system and the lymphocytes egressing from the parenchyma migrate through the lymphatic endothelial cell layer. The sinus lymphatic endothelial cells also orchestrate the organogenesis of lymph nodes, and they undergo bidirectional signalling with other sinus-resident cells, such as subcapsular sinus macrophages, to generate a unique lymphatic niche. In this Review, we consider the structural and functional basis of how the lymph node sinus system coordinates immune responses under physiological conditions, and in inflammation and cancer.

Indications, techniques, and clinical outcomes of thoracic duct interventions in patients: a forgotten literature?

BACKGROUND

The evolution of the "gut-lymph concept" has promoted thoracic duct (TD) lymph drainage as a possible treatment to reduce systemic inflammation and end-organ dysfunction in acute illness. The aim was to review the published experience of thoracic duct interventions (TDIs) aimed at improving clinical outcomes.

METHODS

A search of three databases (MEDLINE, EMBASE, and EMBASE CLASSIC) over the last 60 y. The indications for intervention, the technique, and clinical outcomes were reviewed.

RESULTS

There were a wide range of indications for TDI. These included reducing rejection after transplantation, treating inflammatory diseases, and reducing chronic failure of the liver, kidney, and heart. The techniques included TD cannulation and lymphovenuous fistula. The outcomes were variable and often equivocal, and this appears to reflect poor design quality. There is clinical equipoise regarding a therapeutic role of (TD lymph drainage in acute pancreatitis, and probably other acute diseases.

CONCLUSIONS

Until well-designed clinical trials are undertaken, the clinical benefits of TDIs will remain promising, but uncertain.

Peripheral T-lymphocyte and natural killer cell population imbalance is associated with septic encephalopathy in patients with severe sepsis

Septic encephalopathy (SE) is a diffuse cerebral dysfunction resulting from a systemic inflammatory response, and is associated with an increased risk of mortality. The pathogenesis of SE is complex and multifactorial, but unregulated immune imbalance may be an important factor. The current retrospective study examined the clinical data of 86 patients with severe sepsis who were admitted to the Intensive Care Unit at Zhongshan Hospital, Xiamen University (Xiamen, China) from January, 2014 to January, 2015. The patients were assigned to SE and non-SE patient groups according to the presence or absence of SE. The proportion of T-lymphocyte subsets and natural killer (NK) cells in the immune cell population, representing the function of the immune system, were analyzed for their association with SE and compared with other clinical predictors and biomarkers. The incidence of SE in the patients was 39.5%, and this group demonstrated higher mortality rates (38 vs. 10% in non-SE patients; P=0.001). Univariate analysis revealed that the SE patients reported a lower percentage of cluster of differentiation 4⁺(CD4⁺) T-lymphocytes (51.67±7.12 vs. 60.72±3.70% in non-SE patients; P<0.01), a lower CD4⁺/cluster of differentiation 8⁺(CD8⁺) ratio (1.59±0.32 vs. 1.85±0.26% in non-SE patients; P<0.01) and a higher percentage of NK cells (11.80±1.44 vs. 9.19±2.36% in non-SE patients; P<0.01). Using a binary logistic regression model, the Acute Physiology and Chronic Health Evaluation II score and the percentage of CD4⁺ T-lymphocytes were demonstrated to be independently associated with SE (respectively, P=0.012 and OR, 4.763; P=0.005 and OR, 0.810). An area under the curve analysis of a receiver operating characteristic curve of the two indicators revealed that these were equally powerful measures in prediction of SE (Z=1.247, P>0.05). The present results confirm that SE leads to higher mortality in patients with severe sepsis, and demonstrate that immune imbalance is important in the development of SE. The proportion of CD4⁺ T-lymphocytes present were revealed in the current study to be a powerful predictor of SE in patients with severe sepsis.

Reversal of neutrophil-to-lymphocyte count ratio in early versus late death from septic shock

Introduction

Septic shock is one of the most frequent causes of admission to the intensive care unit (ICU) and is associated with a poor prognosis. Early and late death in septic shock should be distinguished because they may involve different underlying mechanisms. In various conditions, the neutrophil-to-lymphocyte count ratio (NLCR) has been described as an easily measurable parameter to express injury severity. In the present study, we investigated whether the timing of death was related to a particular NLCR.

Methods

We conducted a prospective, single-center, observational study that included consecutive septic shock patients. Severity scores, early (before day 5) or late (on or after day 5 of septic shock onset) ICU mortality, and daily leukocyte counts were collected during the ICU stay. We assessed the association between leukocyte counts at admission and their evolution during the first 5 days with early or late death. The association between patient characteristics (including cell counts) and prognosis was estimated using Cox proportional cause-specific hazards models.

Results

The study included 130 patients who were diagnosed with abdominal (n = 99) or extra-abdominal (n = 31) septic shock. The median (interquartile range) NLCR was 12.5 (6.5–21.2) in survivors and 6.2 (3.7–12.6) in nonsurvivors (p = 0.001). The NLCR at admission was significantly lower in patients who died before day 5 than in survivors (5 [3.5–11.6] versus 12.5 [6.5–21.2], respectively; p = 0.01). From day 1 to day 5, an increased NLCR related to an increase in neutrophil count and a decrease in lymphocyte count was associated with late death (+34.8 % [−8.2 to 305.4] versus −20 % [−57.4 to 45.9]; p = 0.003). Those results were present in patients with abdominal origin sepsis as well as in those with extra-abdominal sepsis, who were analyzed separately.

Conclusions

In the present study, a reversed NLCR evolution was observed according to the timing of death. Septic shock patients at risk of early death had a low NLCR at admission, although late death was associated with an increased NLCR during the first 5 days.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-1144-x) contains supplementary material, which is available to authorized users.

EUS-guided transesophageal study of the human thoracic duct diameter after instillation of intraduodenal fatty acids (EUS-TEST study)

INTRODUCTION

The accession of the thoracic duct (TD) may be vital for obtaining lymph samples, which may be potentially important for early detection of gastrointestinal cancers. The feasibility and safety of endoscopic ultrasound (EUS)-guided TD puncture were recently demonstrated in a swine model. However, the actual process of lymph aspiration is difficult because of small TD diameter (TDD) as well as sluggish flow. This study was designed to examine the change in TDD following intraduodenal instillation of fatty acids (Intralipid(®); manufactured by Fresenius Kabi [Uppsala, Sweden] for Baxter Healthcare [Deerfield, IL]) in patients undergoing diagnostic EUS.

PATIENTS AND METHODS

Ten patients undergoing EUS for routine indications were enrolled in this interventional study at a tertiary-care center in the United States. Baseline TDD was first recorded with EUS in the mediastinum, and the endoscope was advanced into the second part of the duodenum, where 20% Intralipid was instilled. Patients then underwent the complete EUS procedure, and TDD was again measured at 30, 45, 60, 75, and 90 minutes.

RESULTS

Mean age of the patients was 63 years (range, 46-83 years). The mean (±2 standard deviation) TDD at baseline was 0.17±0.04 cm (range, 0.11-0.23 cm). Values for TDD at 30 minutes (0.22±0.03 cm; P=.11), 60 minutes (0.35±0.08 cm; P=.0007), and 90 minutes (0.27±0.08 cm; P=.04) were all higher than the baseline measurement. Maximum increase in TDD was observed at 60 minutes, after which TD started returning toward baseline.

CONCLUSIONS

TDD increases after intraduodenal instillation of Intralipid in human subjects. This change was statistically most significant at 60 minutes. These observations may be critical for aspiration of lymph samples for early detection of gastrointestinal cancers in humans.

Lymphatic pump treatment enhances the lymphatic and immune systems

The osteopathic medical profession has long advocated the use of osteopathic lymphatic pump treatments (LPT) to improve lymphatic circulation, reduce edema and combat infectious disease. However, until recently, there was no scientific evidence that LPT enhances function of the lymphatic and immune systems. This review discusses the physiological functions of the lymphatic system, the ability of LPT to increase lymph flow under normal and experimental conditions, the clinical benefits of LPT, current research models for the study of LPT and the potential mechanisms by which LPT enhances lymphatic and immune function.

Lymphatic pump treatment mobilizes leukocytes from the gut associated lymphoid tissue into lymph

BACKGROUND

Lymphatic pump techniques (LPT) are used clinically by osteopathic practitioners for the treatment of edema and infection; however, the mechanisms by which LPT enhances lymphatic circulation and provides protection during infection are not understood. Rhythmic compressions on the abdomen during LPT compress the abdominal area, including the gut-associated lymphoid tissues (GALT), which may facilitate the release of leukocytes from these tissues into the lymphatic circulation. This study is the first to document LPT-induced mobilization of leukocytes from the GALT into the lymphatic circulation.

METHODS AND RESULTS

Catheters were inserted into either the thoracic or mesenteric lymph ducts of dogs. To determine if LPT enhanced the release of leukocytes from the mesenteric lymph nodes (MLN) into lymph, the MLN were fluorescently labeled in situ. Lymph was collected during 4 min pre-LPT, 4 min LPT, and 10 min following cessation of LPT. LPT significantly increased lymph flow and leukocytes in both mesenteric and thoracic duct lymph. LPT had no preferential effect on any specific leukocyte population, since neutrophil, monocyte, CD4+ T cell, CD8+ T cell, IgG+B cell, and IgA+B cell numbers were similarly increased. In addition, LPT significantly increased the mobilization of leukocytes from the MLN into lymph. Lymph flow and leukocyte counts fell following LPT treatment, indicating that the effects of LPT are transient.

CONCLUSIONS

LPT mobilizes leukocytes from GALT, and these leukocytes are transported by the lymphatic circulation. This enhanced release of leukocytes from GALT may provide scientific rationale for the clinical use of LPT to improve immune function.

Exploring the feasibility of selective depletion of T lymphocyte subsets by whole blood immunoadsorption cytapheresis

Normal turnover of T lymphocytes is slow relative to other blood cells. Consequently, the physical removal of circulating leucocytes by thoracic duct drainage, repeated leukapheresis or blood filtration results in T cell depletion and immunosuppression. However, clinical use of such procedures is impractical compared with immunosuppressive drugs or radiation. None the less, immunosuppression by physical depletion of T cells, avoiding the systemic toxicities of drugs and radiation, might have clinical advantages if immunophenotypically distinct T cell subsets could be depleted selectively. Recent advances in targeted plasma protein apheresis using adsorbent macrobead columns prompted us to determine whether analogous techniques might permit CD4+ T lymphocytes to be removed selectively from whole blood. To explore this possibility, we linked murine anti-human-CD4 and isotype-identical control monoclonal antibodies (mAbs) to agarose, polyacrylamide and polystyrene macrobeads (150-350 microm) and then evaluated the selectivity, specificity and efficiency of macrobead columns to remove CD4+ T cells from anti-coagulated whole blood at varying mAb densities and flow rates. We also examined saturation kinetics and Fc-oriention versus random coupling of mAbs to macrobeads. Sepharose 6MB macrobead (250-350 microm) columns proved to be most effective, selectively removing up to 98% of CD4+ T cells from whole blood. Moreover, depletion efficiency and selectivity were retained when these columns were reused after elution of adherent CD4+ cells. These studies indicate that selective depletion of T lymphocyte subsets by whole blood immunoadsorption apheresis using mAb-linked macrobead columns may be feasible on a clinical scale. It is possible that such apheresis techniques could achieve targeted forms of immunosuppression not possible with drugs or radiation.

Molecular methods to distinguish reactive and neoplastic lymphocyte expansions and their importance in transitional neoplastic states

Although lymphoma and leukemia usually can be diagnosed by routine cytology and histology, some cases present a diagnostic challenge for pathologists and clinicians. Often the dilemma lies in determining whether a population of lymphocytes is reactive or neoplastic. We review currently available methods for analyzing lymphocyte populations by immunophenotyping and by identifying clonally rearranged immunoglobulin and T-cell receptor genes and discuss how these tests can be used to clarify such diagnostic dilemmas. We also describe the detection of chromosomal abnormalities and methods on the horizon, such as gene expression profiling, to identify diagnostically useful oncogenes. Finally, we review the emerging concept of transitional neoplastic states, in which reactive lymphocytes transform to neoplastic lymphocytes in the presence of continued antigenic stimulation, such as that caused by infection with Helicobacter pylori. The existence of transitional neoplastic states underscores the need for an array of molecular diagnostic tools that would improve our ability to characterize lymphocyte populations in human and animal patients and enhance early detection of neoplastic lymphocytes such that eradication of the infectious or inflammatory stimulus could lead to cure.

Lymph sampling and lymphangiography via EUS-guided transesophageal thoracic duct puncture in a swine model

BACKGROUND

The thoracic duct plays an important role in fluid balance, lipid absorption, and transport of immunologically active cells. The thoracic duct is difficult to access but is readily identified by EUS. The present study assessed the feasibility of EUS identification and EUS-guided puncture of the thoracic duct in a swine model.

METHODS

Transesophageal EUS-guided thoracic duct puncture was attempted in 3 animals under fluoroscopy. In two animals, the thoracic duct was identified by cutdown in the neck; in the third animal, EUS-guided puncture was performed under fluoroscopy alone. In one animal, the thoracic duct was opacified by injecting contrast medium. In the second animal, thoracic duct was injected with patent blue and contrast medium.

OBSERVATIONS

Thoracic duct was identified and punctured successfully in all 3 animals. In the first animal, contrast medium containing lymph was aspirated. In the second animal, lymph containing patent blue was aspirated, and, in the third animal, successful puncture was confirmed by obtaining a lymphangiogram.

CONCLUSIONS

This pilot study in an animal model demonstrates that transesophageal EUS-guided puncture of the thoracic duct is feasible and that the technique can be used for lymph sampling and/or lymphangiography.

Lymphocyte subset numbers depend on the bacterial origin of sepsis

OBJECTIVE

To determine the quantitative variances in peripheral blood lymphocyte subsets during sepsis, and their clinical significance.

METHODS

Peripheral blood lymphocyte subsets were enumerated in 32 non-surgical septic patients during the first 14 days of hospitalization; results from septic patients were compared with those from 34 healthy controls. Influences of the severity and the bacterial etiology of sepsis on changes in lymphocyte subsets were also assessed.

RESULTS

Significant decreases (P < 0.05) from normal values of CD4+, CD8+ and total T-lymphocytes were observed in septic patients, but the decline persisted only for CD4+ T-lymphocytes and natural killer (NK) cells for 3 and 7 days, respectively. In addition, the numbers of CD3+/DR+ lymphocytes were significantly elevated on day 14. There were no correlations between these alterations and the severity of sepsis. Gram-positive sepsis (n = 10), which was mainly due to Streptococcus pneumoniae and Staphylococcus aureus, caused prolonged decreases in CD4+, CD8+ and total T-lymphocytes, and a reduction in NK cells, that lasted for >or=14 days. Conversely, patients with sepsis due to Gram-negative pathogens (Neisseria meningitidis, n = 8; enterobacteria, n = 2) achieved full recovery of the subsets within 3 days. Moreover, the patients with Gram-negative sepsis demonstrated a significant increase in B-lymphocytes, and a rise in the numbers of CD3+/DR+ and CD4+ T-lymphocytes, which were more rapid than in patients with Gram-positive sepsis.

CONCLUSION

Our results indicate that Gram-positive sepsis causes stronger suppression of peripheral blood lymphocyte subsets in comparison to sepsis due to Gram-negative pathogens.

Mannose receptor is a novel ligand for L-selectin and mediates lymphocyte binding to lymphatic endothelium

Continuous lymphocyte recirculation between blood and lymphoid tissues forms a basis for the function of the immune system. Lymphocyte entrance from the blood into the tissues has been thoroughly characterized, but mechanisms controlling lymphocyte exit from the lymphoid tissues via efferent lymphatics have remained virtually unknown. In this work we have identified mannose receptor (MR) on human lymphatic endothelium and demonstrate its involvement in binding of lymphocytes to lymphatic vessels. We also show that the binding requires L-selectin, and L-selectin and MR form a receptor-ligand pair. On the other hand, L-selectin binds to peripheral lymph node addressins (PNAds) on high endothelial venules (HEVs) that are sites where lymphocytes enter the lymphatic organs. Interestingly, MR is absent from HEVs and PNAds from lymphatic endothelium. Thus, lymphocyte L-selectin uses distinct ligand molecules to mediate binding at sites of lymphocyte entrance and exit within lymph nodes. Taken together, interaction between L-selectin and MR is the first molecularly defined mechanism mediating lymphocyte binding to lymphatic endothelium.

Effect of preoperative oral immune-enhancing nutritional supplement on patients at high risk of infection after cardiac surgery: a randomised placebo-controlled trial

BACKGROUND

Elderly patients and those with poor ventricular function have increased morbidity and mortality rates when undergoing surgery. We aimed to ascertain whether an oral immune-enhancing nutritional supplement could improve preoperative host defence, and subsequently lower postoperative infections and organ dysfunction in patients undergoing elective cardiac surgery who are at high risk of infection.

METHODS

In this prospective, randomised, double-blind, placebo-controlled study, we randomly assigned 50 patients who were scheduled to undergo coronary artery bypass to receive either an oral immune-enhancing nutritional supplement containing L-arginine, omega3 polyunsaturated fatty acids, and yeast RNA (n=25), or a control (n=25) for a minimum of 5 days. Patients were included if they were aged 70 years or older, or had an ejection fraction of less than 0.4, or were scheduled to undergo mitral valve replacement. The main outcome was preoperative host defence (delayed-type hypersensitivity response to recall antigens, expression of HLA-DR epitopes on monocytes, and concentration of interleukin 6 in plasma). Analysis was per protocol.

FINDINGS

Five patients (two in the treatment group) were excluded because they did not take the minimum dose. Preoperative expression of HLA-DR epitopes on monocytes was significantly higher in patients given the study treatment (109% [95% CI 92-128]) than those given the control (69% [58-82]) compared with baseline (100%) (p=0.02, repeated measures ANOVA). However, concentration of interleukin 6 was significantly lower in the treatment group (0.90 pg/L [0.69-1.18]) than in the control group (1.94 pg/L [1.45-2.59]) (p=0.032, repeated measures ANOVA). Additionally, delayed-type hypersensitivity response to recall antigens improved preoperatively and remained better until hospital discharge.

INTERPRETATION

Intake of an oral immune-enhancing nutritional supplement for a minimum of 5 days before surgery can improve outlook in high-risk patients who are undergoing elective cardiac surgery.

Increased distribution and expression of CD64 on blood polymorphonuclear cells from patients with the systemic inflammatory response syndrome (SIRS)

Evidence is growing to suggest that the multiple organ damage of the systemic inflammatory response syndrome (SIRS) arises from the untoward activity of blood polymorphonuclear cells (PMNs), which upon activation acquire the IgG high affinity receptor, CD64. In the current study, flow cytometry was used to assess the prevalence of CD64-bearing PMNs and the intensity of expression of CD64 in whole blood samples from 32 SIRS patients, 11 healthy normal subjects and from eight non-SIRS patients in the intensive care unit (ICU). The percentage of PMNs expressing CD64 was higher in SIRS patients (mean 65%) than in non-SIRS patients (mean 42%; P < 0.02) and in healthy controls (mean 19%; P < 0.001) and was particularly evident in patients with SIRS and sepsis (mean 71%; P < 0.02) as opposed to SIRS alone (mean 55%). There were more CD64 molecules expressed on PMNs from patients with SIRS (median 1331 molecules/cell) in comparison with PMNs from healthy subjects (median 678 molecules/cell; P < 0.01). The highest intensity of CD64 expression was associated with PMNs from patients with both SIRS and sepsis. Functional studies revealed that the supranormal binding of PMNs from patients with SIRS to endothelial monolayers treated with TNFalpha was impeded by anti-CD64 antibodies (mean 24% inhibition; P < 0.01). Monitoring the distribution of CD64+ PMNs and their level of CD64 expression could be of assistance in the rapid discrimination of patients with SIRS from other ICU patients and in the identification of PMNs which are likely to participate in the pathological manifestations of the disease.

Changes in lymphocyte subpopulations and CD3+/DR+ expression in sepsis

OBJECTIVE

To detect lymphocyte subpopulations and CD3+/DR + expression in sepsis.

METHODS

In a prospective clinical study we evaluated subpopulations of lymphocytes and percentage of CD3+/HLA-DR+ lymphocytes using two-color flow cytometry in 40 patients with sepsis and compared them with 34 healthy adults.

RESULTS

Septic patients, when compared with healthy controls, have significantly lower percentage and absolute numbers of total T lymphocytes and CD4 T lymphocytes (P < 0.01). Absolute numbers of CD8 T lymphocytes, NK cells, CD3+/DR + lymphocytes and CD4/CD8 ratio were also decreased (P < 0.01). The percentage of B lymphocytes was increased (P < 0.01).

CONCLUSION

Our results are in agreement with previous findings in patients with sepsis after major surgery or trauma. The decreases in the percentage and absolute numbers of circulating lymphocyte subsets in non-surgical sepsis could represent a general reaction to stress. Increased percentage of B lymphocytes is most probably related to the bacterial etiology of the disease.

Regional specialization in the mucosal immune system: primed cells do not always home along the same track

According to the current paradigm of lymphocyte trafficking, primed B and T cells extravasate in the intestinal lamina propria chiefly by means of the mucosal homing receptor alpha4beta7, which interacts with the vascular addressin MAdCAM-1. However, as discussed here, this mechanism cannot explain the preferential homing of B cells with a high level of J-chain expression to mucosal effector sites outside the gut.