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Basophilic degranulation: Striking light microscopic visual of peripheral blood smear of a participant with cold urticaria
*Corresponding author: Maharaj Biswas, Department of Zoology, University of Kalyani, Kalyani, West Bengal, India. drmbku@gmail.com
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Received: ,
Accepted: ,
How to cite this article: Biswas M. Basophilic degranulation: Striking light microscopic visual of peripheral blood smear of a participant with cold urticaria. J Hematol Allied Sci. doi: 10.25259/JHAS_35_2026
Abstract
Basophil is the rarest leukocyte, which releases their granules upon exposure to specific antigens called basophilic degranulation. Usually, this moment is hardly observed under microscope as basophilic granules are water soluble and washed away during the staining process. A stained blood film of a 31-year-old woman is presented to illustrate this event precisely using a micrograph where granules have left the basophil and concentrated around the cell like a “cloud.” The basophil with a distinct tri-lobed nucleus, ruptured cell membrane and dispersing granules without staining artifacts confirmed this event which may serve as a potent tool in education, research, and clinical practices.
Keywords
Basophil
Basophilic degranulation
Micrograph
Peripheral blood smear
INTRODUCTION
Shelley[1-6] reported that basophils undergo degranulation during an antigen-antibody reaction. They further reported that this type of findings helps to detect a wide range of allergic diseases in human including drug hypersensitivity,[2-4] cold urticarial,[6] atopic dermatitis,[1] gastrointestinal allergy,[1] and allergies to stinging insects.[1] In humans, degranulation of the sensitized basophil upon exposure to a specific antigen is the foundation of in vitro studies for atopic disease.[3,7] This is not only found in vitro, but in vivo as well, as reported by observing blood if the patient is exposed to penicillin.[2] Although basophilic degranulation is common in both in vivo and in vitro studies, this event in peripheral blood smear is hardly ever reported.
CASE REPORT
A 31-year-old woman with cold articaria came to my research laboratory in winter and gave her blood willingly for routine hematological tests. Her hemogram showed a reduced level of hemoglobin (9.6 g/dL) and erythrocyte (red blood cells) count (3.0 million/mm3), but leukocyte (white blood cell) count (13,500 cells/mL) markedly increased with eosinophilia (7%) and basophilia (4%). The microscopic examination of stained blood smear revealed the presence of an actively degranulating basophil. The accompanying micrographs illustrate [Figures 1 and 2] a classic “explosive or scattering’’ moment of basophilic degranulation where granules have left the basophil, but still they are concentrated around the basophil like a “cloud.” Notably, the dispersion of granules within the thin monolayer of adjacent erythrocytes provides a rare and high-fidelity visual of the release of granules in the form of inflammatory cytokines, histamines, heparin, or others. Before degranulation, the huge number of dark blue-purple granules, background noise, and staining artifacts characteristically obscure the basophilic nucleus, but the distinct tri-lobed basophilic nucleus, ruptured cell membrane, and dispersing granules in the micrographs confirmed the after-effect of basophilic degranulation [Figures 1 and 2].
DISCUSSION
Despite being present in both in vitro and in vivo studies under some circumstances such as antigen-antibody reaction,[8] exposure to specific antigens[9] and atopic disease,[10] patient’s blood experiencing a penicillin reaction,[2] the ideal moment of basophilic degranulation documented here using micrographs has, however, hardly ever reported as the granules are water soluble and washed away or faded during washing step of staining procedure.
CONCLUSION
The precise “explosive or scattering” moment of basophilic degranulation is first captured and illustrated in this report using exceptionally clear micrographs of peripheral blood smear which may serve as a ready reference tool for the study of basophilic degranulation in education, research, and clinical practice. Besides this, basophils release their granules in the form of histamine, cytokines, or others when triggered by cold to attenuate allergic conditions, especially in winter.
Ethical approval:
Institutional Review Board approval is not required.
Declaration of patient consent:
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given consent for their images and other clinical information to be reported in the journal. The patient understands that the patient’s names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Conflicts of interest:
There are no conflicts of interest.
Use of artificial intelligence (AI)-assisted technology for manuscript preparation:
The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.
Financial support and sponsorship: Nil.
References
- Indirect basophil degranulation test for allergy to penicillin and other drugs. JAMA. 1963;184:171-8.
- [CrossRef] [PubMed] [Google Scholar]
- Methods of observing the basophil leucocyte degranulation response. Ann N Y Acad Sci. 1963;103:427-35.
- [CrossRef] [PubMed] [Google Scholar]
- The circulating basophil as an indicator of hypersensitivity in man. Experimental novobiocin sensitization. Arch Dermat. 1963;88:759-67.
- [CrossRef] [PubMed] [Google Scholar]
- Detection of anaphylactic sensitivity by the basophil degranulation response. An experimental study. JAMA. 1962;182:172-8.
- [Google Scholar]
- Role of mast cell and basophil in cold urticaria with associated systemic reaction. JAMA. 1961;177:371-7.
- [CrossRef] [PubMed] [Google Scholar]
- Studies on the degranulation of human basophil leucocytes in vitro. Br J Dermatol. 1968;80:811.
- [CrossRef] [PubMed] [Google Scholar]
- Observations on basophil degranulation as an indicator of antigen-antibody reaction. J Allergy. 1964;35:361-70.
- [CrossRef] [PubMed] [Google Scholar]
- Basophil degranulation: A new method of observation and its correlation with skin testing. J Allergy Clin Immunol. 1972;50:338-47.
- [CrossRef] [PubMed] [Google Scholar]
- The antigen-induced degranulation of basophil leucocytes from atopic subjects, studied by phase-contrast microscopy. Clin Exp Immunol. 1971;8:45-61.
- [Google Scholar]