MRCOG Part 1: Immunology - Essential Study Guide

This is your essential guide to the Immunology section of the MRCOG Part 1 exam. We built it from our own experience of sitting the exam, the RCOG syllabus and the official reading list. It lists the immunology concepts most often tested, section by section.

Why Immunology matters in MRCOG Part 1

Immunology is crucial for understanding how the body defends itself against pathogens and how the immune system plays a role in pregnancy, reproductive health, and various diseases relevant to obstetrics and gynaecology. The MRCOG Part 1 exam will assess your knowledge of basic immunological principles and their clinical implications.

Immunology syllabus, section by section

IInnate Immunity

Cells and Components of Innate Immunity

Phagocytes
  • Types of phagocytes: monocytes/macrophages, neutrophils, mast cells, basophils, eosinophils
  • Process of phagocytosis: engulfing, ingesting, and destroying pathogens
  • Role of chemokines and cytokines in phagocyte activation
  • Lifespan and function of neutrophils
  • Location and function of mast cells
  • Function of eosinophils in parasitic infections
Natural Killer (NK) Cells
  • Role of NK cells in innate and adaptive immunity
  • Mechanisms of NK cell cytotoxicity: antibody-dependent cell-mediated cytotoxicity (ADCC) and recognition of MHC class I downregulation
  • Activation of NK cells by cytokines (IL-2, IFN-γ)
Complement System
  • Functions of the complement system: lysis, opsonization, triggering the complement cascade
  • Pathways of complement activation: classic, alternative, lectin
  • Role of C3 in complement activation
  • Formation of the membrane attack complex (MAC)
  • Consequences of complement deficiencies

IIAdaptive Immunity

B Cells and Antibodies

B Cell Development and Function
  • Location of B cell development (bone marrow)
  • Role of antibodies on B cell surface as antigen receptors
  • Process of B cell activation and differentiation into plasma cells
Immunoglobulins (Antibodies)
  • Structure of immunoglobulins: heavy and light chains, Fab and Fc regions
  • Classes of immunoglobulins: IgG, IgM, IgA, IgE, IgD
  • Functions of each immunoglobulin class
  • Properties of IgM: pentamer structure, first antibody in primary response, complement activation
  • Properties of IgG: major antibody in secondary response, crosses placenta, opsonization
  • Properties of IgA: predominant antibody in secretions, role in mucosal immunity
  • Properties of IgE: role in allergic reactions, binds to mast cells and basophils
  • Properties of IgD: function as a transmembrane antigen receptor on mature B cells
  • Immunoglobulin with the highest molecular weight

T Cells and Cell-Mediated Immunity

T Cell Maturation and Types
  • Process of T cell maturation in the thymus
  • Positive and negative selection of T cells
  • Role of CD4 and CD8 surface molecules
  • Types of T cells: T helper (Th) cells, cytotoxic T (Tc) cells
  • Distinction between alpha/beta and gamma/delta T cells
CD4-positive T Cells
  • Function of CD4 as a cell adhesion molecule and in signal transduction
  • Th1 and Th2 cell subsets and their cytokine profiles
  • Role of Th1 cells in cell-mediated immunity
  • Role of Th2 cells in humoral immunity
  • Factors influencing Th1/Th2 polarization
  • Other CD4-positive T cell types: Th3, Th0, Tr1
CD8-positive T Cells
  • Function of CD8 in stabilizing T cell-target cell interaction
  • Role of Tc cells in killing infected cells
  • Cytokine secretion by CD8-positive T cells

IIIOther Important Immunological Concepts

Antigen-Presenting Cells (APCs)

Function of APCs
  • Role of dendritic cells as 'professional' APCs
  • Capturing, processing, and presenting antigens to T cells

Cytokines

Types and Functions of Cytokines
  • Role of cytokines in innate and adaptive immunity
  • Autocrine, paracrine, and endocrine actions of cytokines
  • Categories of cytokines: interferons, interleukins, chemokines, growth factors
  • Functions of interferons (IFN-α, IFN-β, IFN-γ)
  • Important interleukins (IL-1, IL-2, IL-4, IL-10, IL-12) and their functions
  • Proinflammatory cytokines (IL-1, TNF-α)
  • Role of chemokines in cell migration and chemotaxis
  • Role of growth factors in hematopoiesis

Major Histocompatibility Complex (MHC)

MHC Class I and Class II Molecules
  • Role of MHC molecules in antigen presentation
  • Structure and function of class I MHC molecules
  • Structure and function of class II MHC molecules
  • Types of cells expressing class I and class II MHC molecules
  • Human Leukocyte Antigen (HLA) system

Hypersensitivity Reactions

Types of Hypersensitivity
  • Immediate (Type I) hypersensitivity: mechanism, mediators, examples
  • Antibody-mediated (Type II) hypersensitivity: mechanism, examples (transfusion reactions, hemolytic disease of the newborn)
  • Immune complex (Type III) hypersensitivity: mechanism, examples
  • Delayed-type (Type IV) hypersensitivity: mechanism, variants (contact, tuberculin-type, granulomatous), examples

Transplantation

Types of Transplants and Rejection
  • Types of transplants: autograft, isograft, allograft, xenograft
  • Mechanisms of allograft rejection: allorecognition, role of MHC incompatibility
  • Types of rejection: hyperacute, acute, chronic
  • Graft-versus-host disease
  • Methods to prevent rejection: HLA matching, immunosuppressive drugs

Immune Mechanisms in Pregnancy

Fetus as an Allograft
  • Immune paradox of pregnancy
  • Mechanisms to prevent rejection of the fetus
Immunological Interfaces of Pregnancy
  • Interface 1: extravillous cytotrophoblast and decidual immune cells
  • Interface 2: syncytiotrophoblast and maternal blood
  • Role of decidual NK cells
  • Expression of MHC antigens by the trophoblast (HLA-G, HLA-E, HLA-C)
  • Maternal antibody production and transport across the placenta
  • Th1/Th2 balance in pregnancy
  • Immune mechanisms in disorders of pregnancy (recurrent miscarriage, pre-eclampsia)

How to master Immunology

  • Review: work through each section systematically and understand the core concepts before moving on.
  • Active learning: draw diagrams, build mind maps and explain concepts to someone else.
  • Test yourself: try our free practice questions, then work through the immunology questions in the Uterio question bank.

Additional resources