Background: Hematological abnormalities in COVID-19 infection included quantitative and qualitative changes and should be further characterized. Evaluation for myelodysplastic syndromes (MDS) is usually prompted by abnormal hematologic findings and the presence of dysplastic morphologies. Viral infections are considered to be the cause of dysplastic morphologies and should be considered by morphologists. There are few reports of dysplastic abnormal morphologies in patients with COVID-19 infection. However, such correlations still have to be clarified. Materials and Methods: In the present study, we examined the granulocyte lineage morphological abnormalities in symptomatic RT-PCR-confirmed COVID patients. Peripheral blood samples were collected from 82 patients with symptomatic COVID-19. Blood smears were prepared according to the standard Wright-Giemsa staining procedure. The morphological examination was carried out by two laboratory experts. Results: Blood smear examination revealed common myelodysplastic syndrome (MDS) type abnormalities including but not limited to pseudo-pelger nuclear lobulation (4.8%), hypogranulation (7.3%), Howell-Jolly-like bodies or detached nuclear segments (6.0%) and elongated and thin nuclear filaments (6.0%). One case of abnormal immature granulocyte and ring form nucleus is also evident. Conclusion: Our results accounted for the possibility of active COVID-19 infection in all subjects with granulocyte dysplasia. These results are of practical importance for patients suspected of having myelodysplastic syndromes or disease processes associated with myeloid malignancies.

The dynamic interplay between intramammary IgG, formation of antigen-IgG complexes and effector immune cell function is essential for immune homeostasis within the bovine mammary gland. We explore how changes in the recognition and binding of anti-LPS IgG to the glycolipid \"functional\" core in milk from healthy or clinically diagnosed Escherichia coli (E. coli) mastitis cows\' controls endotoxin function. In colostrum, we found a varied anti-LPS IgG repertoire and novel soluble LPS/IgG complexes with direct IgG binding to the LPS glycolipid core. These soluble complexes, absent in milk from healthy lactating cows, were evident in cows diagnosed with E. coli mastitis and correlated with endotoxin-driven inflammation. E. coli mastitis milk displayed a proportional reduction in anti-LPS glycolipid core IgG compared to colostrum. Milk IgG extracts showed that only colostrum IgG attenuated LPS induced endotoxin activity. Furthermore, LPS-stimulated reactive oxygen species (ROS) in milk granulocytes was only suppressed by colostrum IgG, while IgG extracts of neither colostrum nor E. coli mastitis milk influenced N-formylmethionine-leucyl-phenylalanine (fMLP)-stimulated ROS in LPS primed granulocytes. Our findings support bovine intramammary IgG diversity in health and in response to E. coli infection generate milk anti-LPS IgG repertoires that coordinate appropriate LPS innate-adaptive immune responses essential for animal health.

We previously reported that myeloperoxidase-deficient (MPO-/-) mice develop more severe neutrophil-rich lung inflammation than wild-type mice following intranasal Zymosan administration. Interestingly, we found that these mutant mice with severe lung inflammation also displayed pronounced neutrophilia and anemia, characterized by increased granulopoiesis and decreased erythropoiesis in the bone marrow, compared to wild-type mice. This condition was associated with higher concentrations of granulocyte-colony stimulating factor (G-CSF) in both the lungs and serum, a factor known to enhance granulopoiesis. Neutrophils accumulating in the lungs of MPO-/- mice produced greater amounts of G-CSF than those in wild-type mice, indicating that they are a significant source of G-CSF. In vitro experiments using signal transduction inhibitors and Western blot analysis revealed that MPO-/- neutrophils express higher levels of G-CSF mRNA in response to Zymosan, attributed to the upregulation of the IκB kinase/nuclear factor (NF)-κB pathway and the extracellular-signal-regulated kinase/NF-κB pathway. These findings highlight MPO as a critical regulator of granulopoiesis and erythropoiesis in inflamed tissues.

Phagocytosis is a major cellular mechanism for mollusk granulocytes to eliminate nonself substances and dead cells, and thus to preserve the immune homeostasis. The knowledge of the regulatory mechanisms controlling phagocytic capacity is vital to understanding the immune system. In the present study, an ATF3 homolog (CgATF3) with a typical bZIP domain was identified in the Pacific oyster Crassostrea gigas. Its highly conserved bZIP domain consisted of two structural features, a basic region for DNA binding and a leucine zipper region for dimerization. Its transcript was found to be abundantly expressed in haemocytes, which was induced by Vibrio splendidus stimulation and recombinant CgTNF-2 treatment, along with an increase of its protein content in the nucleus. Moreover, CgATF3 showed a consistent and specific high expression in granulocytes, and CgATF3+ granulocytes were characterized morphologically by the largest diameter, smaller nucleus to cytoplasmic ratio, and abundant cytoplasmic granules, and functionally by a higher capacity for phagocytosis. When CgATF3 expression was inhibited by RNAi, the expression levels of CgRab1, CgRab33 and CgCathepsin L1, as well as the phagocytic rate and index of granulocytes all decreased after V. splendidus stimulation. These results together demonstrated the involvement of CgATF3 in regulating the expressions of Rabs and Cathepsin L1, as well as the phagocytosis of granulocytes in oyster C. gigas.

BACKGROUND: Increasing evidence has revealed that granulocyte has a critical role in tumorigenesis and progression. In this study, Mendelian randomization (MR) analysis was utilized for estimating the causal association between neutrophil percentage and melanoma skin cancer, eosinophil percentage and melanoma skin cancer, basophil percentage and melanoma skin cancer, respectively.
METHODS: The Genome-Wide Association Study (GWAS) ids for melanoma skin cancer, neutrophil percentage, eosinophil percentage and basophil percentage were derived from Integrative Epidemiology Unit (IEU) Open GWAS database. The univariable MR (UVMR) analysis was conducted to estimate the risk using MR-Egger, weighted median, inverse variance weighted (IVW). In addition, sensitivity analysis was conducted to assess the reliability of UVMR results. Finally, the multivariable MR (MVMR) analysis was performed to investigate causality between neutrophil percentage and eosinophil percentage in the presence of both and melanoma skin cancer.
RESULTS: The UVMR indicated that neutrophil percentage and eosinophil percentage were significantly and causally related to melanoma skin cancer, with neutrophil percentage [p = 0.025, odds ratio (OR) = 1.002] as a risk factor and eosinophil percentage (p = 7.04E-06, OR = 0.997) as a protective factor. Moreover, MVMR analysis indicated eosinophil percentage remained the protective factor (p = 0.003, OR = 0.998), while the causality of neutrophil percentage and melanoma skin cancer became insignificant (p > 0.05).
CONCLUSIONS: The causal relationships of neutrophil percentage and melanoma skin cancer, eosinophil percentage and melanoma skin cancer were shown by this study, which provided a reference for subsequent research and treatment related to melanoma skin cancer.

Severe alcohol-associated hepatitis (AH) is a life-threatening form of alcohol-associated liver disease. Liver neutrophil infiltration is a hallmark of AH, yet the effects of alcohol on neutrophil functions remain elusive. Identifying therapeutic targets to reduce neutrophil-mediated liver damage is essential. Bruton\'s tyrosine kinase (BTK) plays an important role in neutrophil development and function; however, the role of BTK in AH is unknown. Using RNA sequencing of circulating neutrophils, we found an increase in Btk expression (P = 0.05) and phosphorylated BTK (pBTK) in patients with AH compared with healthy controls. In vitro, physiologically relevant doses of alcohol resulted in a rapid, TLR4-mediated induction of pBTK in neutrophils. In a preclinical model of AH, administration of a small-molecule BTK inhibitor (evobrutinib) or myeloid-specific Btk knockout decreased proinflammatory cytokines and attenuated neutrophil-mediated liver damage. We found that pBTK was essential for alcohol-induced bone marrow granulopoiesis and liver neutrophil infiltration. In vivo, BTK inhibition or myeloid-specific Btk knockout reduced granulopoiesis, circulating neutrophils, liver neutrophil infiltration, and liver damage in a mouse model of AH. Mechanistically, using liquid chromatography-tandem mass spectrometry, we identified CD84 as a kinase target of BTK, which is involved in granulopoiesis. In vitro, CD84 promoted alcohol-induced interleukin-1β and tumor necrosis factor-α in primary human neutrophils, which was inhibited by CD84-blocking antibody treatment. Our findings define the role of BTK and CD84 in regulating neutrophil inflammation and granulopoiesis, with potential therapeutic implications in AH.

Perfluorohexane sulfonate (PFHxS) is a member of the per- and polyfluoroalkyls (PFAS) superfamily of molecules, characterized by their fluorinated carbon chains and use in a wide range of industrial applications. PFHxS and perfluorooctane sulfonate are able to accumulate in the environment and in humans with the approximated serum elimination half-life in the range of several years. More recently, some PFAS compounds have also been suggested as potential immunosuppressants. In this study, we analyze immune cell numbers in mice following 28-d repeated oral exposure to potassium PFHxS at 12, 120, 1,200, and 12,000 ng/kg/d, with resulting serum levels ranging up to ∼1,600 ng/ml, approximating ranges found in the general population and at higher levels in PFAS workers. The immunosuppressant cyclophosphamide was analyzed as a positive control. B cells, T cells, and granulocytes from the bone marrow, liver, spleen, lymph nodes, and thymus were evaluated. We found that at these exposures, there was no effect of PFHxS on major T or B cell populations, macrophages, dendritic cells, basophils, mast cells, eosinophils, neutrophils, or circulating Ab isotypes. By contrast, mice exposed to cyclophosphamide exhibited depletion of several granulocyte and T and B cell populations in the thymus, bone marrow, and spleen, as well as reductions in IgG1, IgG2b, IgG2c, IgG3, IgE, and IgM. These data indicate that exposures of up to 12,000 ng/kg of PFHxS for 28 d do not affect immune cell numbers in naive mice, which provides valuable information for assessing the risks and health influences of exposures to this compound.

OBJECTIVE: We aimed to examine the role of circulating immature granulocytes (IGs) in assessing Diabetic Nephropathy (DN) mainly and also associations of other leukocyte parameters with DN.
METHODS: In this retrospective cross-sectional study, a total of 164 Diabetes Mellitus patients were grouped as normoalbuminuric and microalbuminuric according to urinary albumin excretion in the course of admission. Neutrophil-lymphocyte ratio (NLR), IG count (IG#) and IG percentage (IG%) levels were compared between the groups. The value of IG# and IG% levels in detecting microalbuminuria was analyzed with the Receiver operating characteristic (ROC) curve.
RESULTS: NLR was remarkably higher in the microalbuminuric group (p = 0.036). Correlation results in the microalbuminuric group were as follows: A feeble positive correlation between neutrophil count (NEU#) and serum creatinine and albumin-to- creatinine ratio (ACR) (p = 0.036, r = 0.261; p = 0.005, r = 0.347, respectively), a feeble positive correlation between lymphocyte count (LYM#) and estimated glomerular filtration rate (p = 0.021, r = 0.285). Correlation results in the normooalbuminuric group were as follows: A feeble positive correlation between NEU# and ACR (p = 0.043, r = 0.204), a feeble negative correlation between LYM# and serum creatinine (p = 0.042, r = -0.205), a poor positive correlation between IG# and ACR and HBA1C% (p = 0.048, r = 0.199; p = 0.004, r = 0.290, respectively), a positive poor correlation between IG% and HBA1C% (p = 0.019, r = 0.235). Area under the ROC curve values for IG# and IG% were not statistically noteworthy in detecting microalbuminuria (p = 0.430; p = 0.510, respectively).
CONCLUSIONS: IG# and IG% values are insufficient to predict immediate microalbuminuria, but could be considered a weak biomarker for renal damage in normoalbuminuric (<30 mg/g) diabetic patients. Further researches are needed for the use of leukocyte parameters in evaluating DN.

Insufficient sleep duration may lead to a series of immune dysfunctions. One of the factors influencing this effect could be physical activity (PA). The study aimed to assess the impact of deprivation of sleep (DS) on selected inflammatory parameters. Seventy-seven participants completed the protocol consisting of polysomnography (PSG) conducted in a sleep laboratory and DS, monitored with an actigraph. PA was assessed with actigraphy, which categorized participants as active or inactive. White blood cells (WBC) values negatively correlated with sleep efficiency based on sleep diaries and PSG parameters (total sleep time, sleep efficiency, and REM duration), but regression analysis showed that WBC depends only on the sleep diary parameter. Granulocytes (GRA) positively correlated with REM latency, and negatively with sleep efficiency. After DS, all participants exhibited an elevated GRA count. The number of WBC and GRA increased also in the active group; inactive participants showed no changes in inflammatory parameters. The overall number of WBC depends primarily on the quality of sleep over a period of several days. Under the influence of sleep deprivation, the number of GRA increases, but the number of leukocytes depends on the level of physical activity during DS.

Granulocyte colony-stimulating factor (G-CSF) is widely used to enhance myeloid recovery after chemotherapy and to mobilize hematopoietic stem cells (HSCs) for transplantation. Unfortunately, through the course of chemotherapy, cancer patients can acquire leukemogenic mutations that cause therapy-related myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). This raises the question of whether therapeutic G-CSF might potentiate therapy-related MDS/AML by disproportionately stimulating mutant HSCs and other myeloid progenitors. A common mutation in therapy-related MDS/AML involves chromosome 7 deletions that inactivate many tumor suppressor genes, including KMT2C. Here, we show that Kmt2c deletions hypersensitize murine HSCs and myeloid progenitors to G-CSF, as evidenced by increased HSC mobilization and enhanced granulocyte production from granulocyte-monocyte progenitors (GMPs). Furthermore, Kmt2c attenuates the G-CSF response independently from its SET methyltransferase function. Altogether, the data raise concerns that monosomy 7 can hypersensitize progenitors to G-CSF, such that clinical use of G-CSF may amplify the risk of therapy-related MDS/AML.