Ryo Hisamune ¹, Kazuma Yamakawa ¹, Katsuhide Kayano ¹, Noritaka Ushio ¹, Takeshi Wada ², Kohei Taniguchi ³, Akira Takasu ¹ Acute Med Surg. . 2024 Aug 29;11(1):e70003. doi: 10.1002/ams2.70003. eCollection 2024 Jan-Dec.

Aims: SARS-CoV-2 causes systemic immune dysfunction, leading to severe respiratory dysfunction and multiorgan dysfunction. Granulocyte and monocyte adsorptive apheresis (GMA) therapy is designed to regulate an excessive inflammatory response and has been proposed as a potential therapeutic strategy for coronavirus disease 2019 (COVID-19). We aimed to investigate a targeted subset of granulocytes and monocytes to be removed after GMA therapy in patients with severe COVID-19 infection.

Methods: We established an ex vivo experimental system to study the effects of GMA. Blood samples were collected into EDTA-treated tubes and a mixture of blood samples and cellulose acetate beads was used in GMA. After GMA, blood samples were removed, and the granulocyte and monocyte subtypes before and after GMA were determined by CyTOF mass cytometry. To analyze mass cytometry data with a self-organizing map, hierarchical clustering was used to determine the appropriate number of metaclusters from t-distributed stochastic neighbor embedding.

Results: We included seven patients with severe COVID-19 and four age- and sex-matched volunteers. Granulocyte subsets removed by GMA strongly expressed CD11b, CD16, and CD66b, and weakly expressed CD11c, consistent with mature and activated neutrophils. Monocyte subsets strongly expressed CD14, weakly expressed CD33 and CD45RO, and did not express CD16. These subsets were indicated to promote the release of inflammatory cytokines and activate T cells.

Conclusions: The identification of the granulocyte and monocyte subsets removed after GMA in patients with severe COVID-19 may help explain the potential mechanism underlying the effectiveness of GMA in COVID-19 and other inflammatory diseases.

Tomomi Fujisawa ¹, Kana Murase, Hiroyuki Kanoh, Masao Takemura, Hidenori Ohnishi, Mariko Seishima, Ther Apher Dial. 2012 Oct;16(5):436-44.

Generalized pustular psoriasis (GPP) is a subtype of psoriasis with strong association with activated neutrophils. Adsorptive granulocyte and monocyte apheresis (GMA) is an extracorporeal intervention for selective depletion of activated granulocytes and monocytes. However, the immunological mechanism(s) for the effect of GMA on patients is not fully defined yet. We investigated the effects of GMA on the ratio of CD14(+) CD16(+) proinflammatory monocytes/CD14(+) monocytes and cytokine/chemokine production by these leukocytes including CXCL8, CCL2, CCL3, CCL4, CCL5 and tumor necrosis factor (TNF)-α in five patients with active GPP. CD14(+) CD16(+) monocytes were significantly elevated in patients with active GPP, and GMA markedly reduced the CD14(+) CD16(+) /CD14(+) ratio together with improvement of patients’ clinical symptoms. The serum levels of CXCL8, CCL3 and CCL4 were increased in active GPP patients. Likewise, CCL2 production from monocytes was increased in active GPP patients. Further, CCL3 and CCL4 production from monocytes in active GPP patients were reduced after a course of GMA. Serum CCL5 level and the release of CCL5 from monocytes in active GPP were significantly reduced, but TNF-α level in active GPP was similar to controls. Based on these results, we believe that in addition to neutrophils, elevated CD14(+) CD16(+) proinflammatory monocytes are part of the immune pathology in GPP. Accordingly, selective depletion of CD14(+) CD16(+) monocytes by GMA should be therapeutic in this condition.

https://pubmed.ncbi.nlm.nih.gov/23046368/

Shin-ichiro Takeda, Toru Sato, Tatsuro Katsuno, Tomoo Nakagawa, Yoshiko Noguchi, Osamu Yokosuka & Yasushi Saito

Dig Dis Sci 55, 1886–1895 (2010). https://doi.org/10.1007/s10620-009-0974-2

Background:  Two main functionally distinct monocytes phenotypes are known: the CD14hiCD16− “classical” and the CD14+CD16+ “proinflammatory” phenotypes. The latter phenotype is elevated in patients with ulcerative colitis (UC) and is suspected to have a major role in the immunopathogenesis of UC. Aim: To selectively deplete circulating proinflammatory CD14+CD16+ monocyte phenotype. Methods: Seven corticosteroid-naïve patients with UC (clinical activity index = 8.7 ± 1.3) and seven healthy subjects were included. In patients with UC, granulocyte/monocyte adsorption (GMA) was done with an Adacolumn that selectively adsorbs leucocytes of the myeloid lineage. Blood from all subjects at baseline and from the patients immediately after the first GMA session was processed. Isolated monocytes were subjected to fluorescence-activated cell sorter analyses. Results: The seven UC patients achieved remission (CAI ≤4) after 5–10 GMA sessions. GMA induced a strong fall in the ratio (%) of CD14+CD16+ to CD14hiCD16− monocytes, from 10.0 ± 1.4 to 3.0 ± 0.9. Further, expressions of α4 integrin (374.8 ± 26.1 mean fluorescence intensity, MFI) and CX3CR1 (49.5 ± 4.6 MFI) were significantly high on CD14+CD16+monocytes as compared with on CD14hiCD16− monocytes (169.2 ± 17.2 and 33.2 ± 3.6 MFI, respectively). Additionally, GMA significantly increased the ratio of the CD14hiCD16−CCR2low “immature” monocytes from 3.74 ± 0.62 to 8.11 ± 0.56 MFI. Conclusions: We found high expressions of α4 integrin and CX₃CR1 on monocytes in patients with active UC, known to promote the extravasation of CD14⁺CD16⁺ monocytes into the mucosa. GMA effectively depletes CD14⁺CD16⁺ monocytes and concomitantly increases D14^hiCD16⁻CCR2^low “immature” monocytes; thus, GMA was associated with the emergence of less inflammatory monocyte phenotype in circulation.

https://link.springer.com/article/10.1007%2Fs10620-009-0974-2#citeas