Sex differences in leukocyte profile in ST-elevation myocardial infarction patients

Multiomic analyses uncover immunological signatures in acute and chronic coronary syndromes

Acute and chronic coronary syndromes (ACS and CCS) are leading causes of mortality. Inflammation is considered a key pathogenic driver of these diseases, but the underlying immune states and their clinical implications remain poorly understood. Multiomic factor analysis (MOFA) allows unsupervised data exploration across multiple data types, identifying major axes of variation and associating these with underlying molecular processes. We hypothesized that applying MOFA to multiomic data obtained from blood might uncover hidden sources of variance and provide pathophysiological insights linked to clinical needs. Here we compile a longitudinal multiomic dataset of the systemic immune landscape in both ACS and CCS (n = 62 patients in total, n = 15 women and n = 47 men) and validate this in an external cohort (n = 55 patients in total, n = 11 women and n = 44 men). MOFA reveals multicellular immune signatures characterized by distinct monocyte, natural killer and T cell substates and immune-communication pathways that explain a large proportion of inter-patient variance. We also identify specific factors that reflect disease state or associate with treatment outcome in ACS as measured using left ventricular ejection fraction. Hence, this study provides proof-of-concept evidence for the ability of MOFA to uncover multicellular immune programs in cardiovascular disease, opening new directions for mechanistic, biomarker and therapeutic studies.

Single-Cell Dissection of the Immune Response After Acute Myocardial Infarction

BACKGROUND

The immune system's role in ST-segment-elevated myocardial infarction (STEMI) remains poorly characterized but is an important driver of recurrent cardiovascular events. While anti-inflammatory drugs show promise in reducing recurrence risk, their broad immune system impairment may induce severe side effects. To overcome these challenges, a nuanced understanding of the immune response to STEMI is needed.

METHODS

For this, we compared peripheral blood mononuclear single-cell RNA-sequencing (scRNA-seq) and plasma protein expression over time (hospital admission, 24 hours, and 6-8 weeks post-STEMI) in 38 patients and 38 controls (95 995 diseased and 33 878 control peripheral blood mononuclear cells).

RESULTS

Compared with controls, classical monocytes were increased and CD56dim natural killer cells were decreased in patients with STEMI at admission and persisted until 24 hours post-STEMI. The largest gene expression changes were observed in monocytes, associating with changes in toll-like receptor, interferon, and interleukin signaling activity. Finally, a targeted cardiovascular biomarker panel revealed expression changes in 33/92 plasma proteins post-STEMI. Interestingly, interleukin-6R, MMP9 (matrix metalloproteinase-9), and LDLR (low-density lipoprotein receptor) were affected by coronary artery disease-associated genetic risk variation, disease status, and time post-STEMI, indicating the importance of considering these aspects when defining potential future therapies.

CONCLUSIONS

Our analyses revealed the immunologic pathways disturbed by STEMI, specifying affected cell types and disease stages. Additionally, we provide insights into patients expected to benefit most from anti-inflammatory treatments by identifying the genetic variants and disease stage at which these variants affect the outcome of these (drug-targeted) pathways. These findings advance our knowledge of the immune response post-STEMI and provide guidance for future therapeutic studies.

Circulating Lymphocyte Trafficking to the Bone Marrow Contributes to Lymphopenia in Myocardial Infarction

Some patients with myocardial infarction (MI) exhibit lymphopenia, a reduction in blood lymphocyte count. Moreover, lymphopenia inversely correlates with patient prognosis. The objective of this study was to elucidate the underlying mechanisms that cause lymphopenia after MI. Multiparameter flow cytometric analysis demonstrated that MI induced profound B and T lymphopenia in a mouse model, peaking at day 1 post-MI. The finding that non-MI control and MI mice exhibited similar apoptotic rate for blood B and T lymphocytes argues against apoptosis being essential for MI-induced lymphopenia. Interestingly, the bone marrow in day 1 post-MI mice contained more B and T cells but showed less B and T cell proliferation, compared to day 0 controls. This suggests that blood lymphocytes may travel to the bone marrow after MI. This was confirmed by adoptive transfer experiments demonstrating that MI caused the loss of transferred lymphocytes in the blood, but the accumulation of transferred lymphocytes in the bone marrow. To elucidate the underlying signaling pathways, β2 adrenergic receptor or sphingoshine-1-phosphate receptor type 1 (S1PR1) was pharmacologically blocked respectively. β2 receptor inhibition had no significant effect on blood lymphocyte count, whereas S1PR1 blockade aggravated lymphopenia in MI mice. Further, we discovered that MI-induced glucocorticoid release triggered lymphopenia. This was supported by the findings that adrenalectomy (ADX) completely prevented mice from MI-induced lymphopenia, and supplementation with corticosterone in adrenalectomized MI mice re-induced lymphopenia. In conclusion, our study demonstrates that MI-associated lymphopenia involves lymphocyte redistribution from peripheral blood to the bone marrow, which is mediated by glucocorticoids.

Reference intervals of white blood cell parameters for healthy adults in japan

INTRODUCTION

While white blood cell (WBC) parameters have been suggested to depend on ethnicity and gender, reference intervals in healthy Asian populations are limited. The present study established reference intervals of WBC parameters for healthy adults in Japan.

METHODS

A total of 750 healthy adults (447 women and 303 men; 18-67 years old, median 40 years old) at 7 Japanese centers who participated in regular medical checkups entered this study. The WBC parameters were measured using automated hematocytometers and blood film reviews by a manual microscopic examination.

RESULTS

The reference intervals of the WBC parameters according to gender in healthy adults were determined. Age-specific decreases in WBC counts of both gender groups and in neutrophil counts of women were noted. Favorable correlations between the hematocytometer and microscopic methods were found in neutrophils, lymphocytes, and eosinophils but not in monocytes or basophils.

CONCLUSION

This study suggests the need to consider gender and age in the clinical use of reference intervals of WBC parameters.

Clinical Relevance of Changes in Peripheral Blood Cells After Intracranial Aneurysm Rupture

BACKGROUND

The rupture of an intracranial aneurysm (IA) causes a systemic response that involves an immune/inflammatory reaction. We sought to characterize the systemic response to IA rupture.

METHODS

We included 19 patients in the acute phase of IA rupture and 20 control subjects. Flow cytometry was used to analyze alterations in the level of mononuclear leukocytes. Cell-related parameters, including the neutrophil-to-lymphocyte ratio (NL-R), lymphocyte-to-monocyte ratio (LM-R), platelet-to-lymphocyte ratio (PL-R), and systemic immune-inflammation index (SII), were calculated, and the relationship between the analyzed hematological parameters and clinical status was investigated.

RESULTS

Patients with ruptured IAs presented with significantly higher white blood cells (WBC) and neutrophil counts but lower lymphocyte counts than control subjects. NL-R and SII values were higher and the LM-R was lower in the acute phase after IA rupture. Analyzing the severity of clinical status and the outcome of patients with subarachnoid hemorrhage, we found that patients with poor clinical status, as measured by the Glasgow Coma Scale (GCS) and the Hunt and Hess scale, had significantly lower lymphocyte counts and higher NL-R, PL-R and SII values than those with good clinical status. Additionally, patients with lower GCS scores presented a lower proportion of CD3+CD4-CD8- cells. Worse outcomes assessed at discharge were associated with lower lymphocyte counts but higher PL-R values.

CONCLUSIONS

The current study pointed to the significance of systemic immune and inflammatory responses after IA rupture and the potential clinical utility of hematological parameters, which can be easily calculated. In particular, the role of DN T cells and the significance of the SII as a marker related to clinical status should be further investigated.