Evidence map›Paper›PMID 32812697›Full record

ArticlePharmacology research & perspectives2020

Neutrophil fluorescence in clozapine users is attributable to a 14kDa secretable protein.

Sera A J de With, Wai H Man, Coen Maas, Maarten Ten Berg, Wiepke Cahn, Arnold C Koekman, Wouter W van Solinge, Tamar Tak

Open access · goldAbstract read
In one paragraph

Article in Pharmacology research & perspectives, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
0.1field-weighted citation impact, top 69% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed, 2 citations in OpenAlex.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors at 1 institution in 1 country.

Sera A J de WithDepartment of Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands.ORCID 0000-0003-3825-3348
Wai H ManDepartment of Clinical Pharmacy, University Medical Center Utrecht, Utrecht, The Netherlands.
Coen MaasDepartment of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands.
Maarten Ten BergDepartment of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands.
Wiepke CahnDepartment of Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands.
Arnold C KoekmanDepartment of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands.
Wouter W van SolingeDepartment of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands.
Tamar TakDepartment of Respiratory Medicine, Laboratory of Translational Immunology, University Medical Center Utrecht, Utrecht, The Netherlands.
University Medical Center Utrecht · NL

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Clozapine is the only antipsychotic agent with demonstrated efficacy in refractory schizophrenia. However, use of clozapine is hampered by its adverse effects, including potentially fatal agranulocytosis. Recently, we showed an association between neutrophil autofluorescence and clozapine use. In this study, we evaluated the subcellular localization of clozapine-associated fluorescence and tried to elucidate its source. Neutrophils of clozapine users were analyzed with fluorescence microscopy to determine the emission spectrum and localization of the fluorescence signal. Next, these neutrophils were stimulated with different degranulation agents to determine the localization of fluorescence. Lastly, isolated neutrophil lysates of clozapine users were separated by SDS-PAGE and evaluated. Clozapine-associated fluorescence ranged from 420 nm to 720 nm, peaking at 500-550 nm. Fluorescence was localized in a large number of small loci, suggesting granular localization of the signal. Neutrophil degranulation induced by Cytochalasin B/fMLF reduced fluorescence, whereas platelet-activating factor (PAF)/fMLF induced degranulation did not, indicating that the fluorescence originates from a secretable substance in azurophilic granules. SDS-PAGE of isolated neutrophil lysates revealed a fluorescent 14kDa band, suggesting that neutrophil fluorescence is likely to be originated from a 14kDa protein/peptide fragment. We conclude that clozapine-associated fluorescence in neutrophils is originating from a 14kDa soluble protein (fragment) present in azurophilic granules of neutrophils. This protein could be an autofluorescent protein already present in the cell and upregulated by clozapine, or a protein altered by clozapine to express fluorescence. Future studies should further explore the identity of this protein and its potential role in the pathophysiology of clozapine-induced agranulocytosis.

Indexed as

Antipsychotic AgentsCase-Control StudiesClozapineCytochalasin BElectrophoresis, Polyacrylamide GelGene Expression RegulationHumansLuminescent ProteinsMicroscopy, FluorescenceMolecular WeightNeutrophilsPeptide FragmentsPlatelet Activating FactorSchizophreniaAntipsychotic AgentsClozapineCytochalasin BLuminescent ProteinsPeptide FragmentsPlatelet Activating Factorazurophilic granulesclozapineneutrophils

Identifiers

PMID32812697
PMCPMC7437349
OpenAlexW3073547964

What OpenQuestion holds

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LicenceCC BY-NC-ND
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.