Skip to content
Epomedicine
Epomedicine

Mnemonics, Simplified Concepts & Thoughts

  • Medical Students
  • Bedside Clinics
  • Case Reports
  • Emergency Medicine
  • Blog
  • Surgical Skills
  • Medical Mnemonics
Epomedicine

Mnemonics, Simplified Concepts & Thoughts

neutrophil granules

Granular contents of Neutrophils and Platelets

Epomedicine, Jan 19, 2017

Neutrophil Granules

Azurophilic (Primary) Granules

  • These are lysosomes that occur in all granulocytes, as well as in lymphocytes and monocytes.
  • In addition to expected lysosomal hydrolases, they also contain peroxidases (used to demonstrate azurophilic granules chemically).
  • Develop earlier than specific granules.
  • Stains blue/purple by Romanowsky stain.

Mnemonic: ABCDE MnOP

  1. Acid hydrolase
  2. BPI (Bactericidal Permeability Increasing) protein
  3. Cathepsin G
  4. Defensin
  5. Elastase
  6. Myeloperoxidase (MPO)

neutrophil granules

Specific (Secondary) Granules

  • Do not stain intensely with Romanowsky stain.
  • Smaller and more numerous than specific granules.

Mnemonic: COLA

  1. Collagenase
  2. Cathelicidin
  3. Oxidase (NADPH oxidase)
  4. Lactoferrin
  5. Alkaline phosphatase

Common to both Azurophilic and Specific Granules

  1. Lysozyme
  2. Phospholipase A2 (PLP A2)

Tertiary Granules

  • Cathepsin
  • Gelatinase

Defect in Neutrophil Granules

1. Alpha granule defect:

Myeloperoxidase (MPO) deficiency:

  • Most common neutrophil defect.
  • Microbicidal activity of neutrophil is delayed but not absent (defective HOCl formation).
  • Acquired form is seen in AML.

Chediak-Higashi Syndrome (CHS):

  • Defect in LYST (lysosomal transport) protein, encoded by CHS1 gene at 1q42.
  • Abnormal giant alpha granules, impaired chemotaxis and phagolysosome formation leading to severe bacterial infections.
  • Giant granules in: melanocytes and hair (oculocutaneous albinism), nerve tissue (peripheral neuropathy).

2. Specific granule defect (SGD):

  • Misnomer
  • Defect of both primary and specific granules: Absent specific granules + Absent Lactoferrin and ALP (primary granules) but normal MPO.

3. NADPH oxidase deficiency: Chronic Granulomatous Disease (CGD)

  • Mostly X-linked recessive trait; 30% autosomal recessive
  • Infections due to catalse positive organisms (organisms that destroy their own hydrogen peroxide) – extensive inflammatory reactions, and lymph node suppuration is common despite administration of appropriate antibiotics.

Platelet Granules

platelet granules

Alpha granules

Mnemonic: Alpha granules are bigger like Alpha males. These are bigger molecules like proteins and peptides. The granules can be remembered using mnemonic Platelet Function Test (PFT).

  1. P-selectin
  2. Platelet factor 4
  3. Platelet Derived Growth Factor (PDGF) and othr growth factors
  4. Fibronectin
  5. Fibrinogen and other factors (factor V, VIII and vWF)
  6. Transforming Growth Factor – beta (TGF-beta)

Delta (Dense) granules

Mnemonic: Delta granules are smaller and weakers like Delta males. These are smaller molecules. It can be remembered using mnemonic – CAN.

  1. Cations (Ca++, Mg++)
  2. Amines (Serotonin, Histamine)
  3. Nucleotides (ADP, ATP, PPi)

Lysosomes

Defect in Platelet Granules

Alpha granule defect:

  • Gray platelet syndrome (Alpha storage pool defect) – characterized by thrombocytopenia and abnormal enlarged gray-blue platelets with a washed-out appearance due to deficeint alpha granules.
  • Quebec platelet disorder – an autosomal dominant trait caused by deficient platelet alpha granule factor V (due to increased expression of alpha granule urokinase-type plasminogen activator that generates plasmin and cleaves factor V) but normal plasma factor V.

Delta granule defect:

  • Delta storage pool defect – Normal number and normal appearing platelets in peripheral smear, absence of dense granules in electron microscopy and impaired second wave of platelet aggregation (prolonged bleeding time).
  • Hermansky-Pudlak syndrome and Chediak-Higasghi syndrome – Rare autosomal disorders that have in common platelet dense granule deficiency, albinism and lysosomal granule defects.

 

32 shares
  • Facebook24
  • Twitter
PGMEE, MRCS, USMLE, MBBS, MD/MS General conceptsHematologyPathology

Post navigation

Previous post
Next post

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Epomedicine. Granular contents of Neutrophils and Platelets [Internet]. Epomedicine; 2017 Jan 19 [cited 2025 May 9]. Available from: https://epomedicine.com/medical-students/granular-contents-neutrophils-platelets/.

Pre-clinical (Basic Sciences)

Anatomy

Biochemistry

Community medicine (PSM)

Embryology

Microbiology

Pathology

Pharmacology

Physiology

Clinical Sciences

Anesthesia

Dermatology

Emergency medicine

Forensic

Internal medicine

Gynecology & Obstetrics

Oncology

Ophthalmology

Orthopedics

Otorhinolaryngology (ENT)

Pediatrics

Psychiatry

Radiology

Surgery

RSS Ask Epomedicine

  • What to study for Clinical examination in Orthopedics?
  • What is the mechanism of AVNRT?

Epomedicine weekly

  • About Epomedicine
  • Contact Us
  • Author Guidelines
  • Submit Article
  • Editorial Board
  • USMLE
  • MRCS
  • Thesis
©2025 Epomedicine . All rights reserved.