Primary Immunodeficiencies Overview Quiz

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Questions and Answers

What is a common symptom of primary immunodeficiencies typically seen in infants?

Recurrent infections (correct)

Persistent cough

High fever

Skin rashes

Which of the following best describes the classification of primary immunodeficiencies affecting T lymphocytes?

Cell Mediated Immunity (CMI) defects (correct)

B lymphocyte defects

Phagocyte dysfunction

Combined B and T cell defects

Which of the following is NOT a hallmark of primary immune deficiencies?

High body temperature (correct)

Frequent medical intervention

Symptoms starting in childhood

Developmental delay

What is the risk associated with stem cell transplantation in the treatment of immunodeficiencies?

Rejection of transplant Signup and view all the answers

What type of infections are commonly seen in patients with Chronic Granulomatous Disease?

Fungal infections Signup and view all the answers

Which of the following is a primary consideration when deciding on immunodeficiency treatments?

Risk: Benefit ratio Signup and view all the answers

How does severe primary immunodeficiency typically affect a child's growth?

Failure to thrive Signup and view all the answers

Which of the following is not a type of primary immunodeficiency as classified by WHO?

Autoimmune disorders Signup and view all the answers

What is a common symptom presented by patients with complement deficiencies?

Developmental delay Signup and view all the answers

Which of the following is associated with X-linked agammaglobulinaemia (XLA)?

Bruton’s Tyrosine Kinase deficiency Signup and view all the answers

What are typical clinical features of Di George Syndrome?

Facial abnormalities and cardiac defects Signup and view all the answers

In patients with severe combined immunodeficiencies (SCID), what is a common outcome if left untreated?

Mortality within the first year of life Signup and view all the answers

What laboratory finding is expected in Di George Syndrome?

Minimal or no thymus on ultrasound Signup and view all the answers

What is an appropriate treatment for managing infections in patients with complement deficiencies?

Prophylactic antibiotic cover Signup and view all the answers

In XLA, what happens to the immune system?

Decreased levels of circulating B cells Signup and view all the answers

What does the 'CATCH 22' mnemonic refer to in Di George Syndrome?

Cardiac abnormalities, antibody deficiencies, T cell deficit, hypocalcemia, 22q11 deletion Signup and view all the answers

What is the primary difference between HIV-1 and HIV-2?

HIV-1 is the global common infection, while HIV-2 is mainly found in W Africa. Signup and view all the answers

Which cells are primarily targeted by HIV for infection?

T cells, macrophages, and dendritic cells. Signup and view all the answers

What is the estimated number of people infected with HIV worldwide by the end of 2023?

39.9 million. Signup and view all the answers

What is the primary mode of HIV transmission globally?

Sexual intercourse. Signup and view all the answers

During which phase of HIV infection does seroconversion typically occur?

Acute phase. Signup and view all the answers

Which of the following proteins is involved in binding HIV to host cells?

Gp41. Signup and view all the answers

What type of virus is HIV classified as?

Single-stranded diploid RNA retrovirus. Signup and view all the answers

What is the main purpose of antiretroviral therapy for individuals with HIV?

To reduce viral load and improve quality of life. Signup and view all the answers

What is the mean duration of the asymptomatic phase of HIV infection?

10 years Signup and view all the answers

Which of the following symptoms is NOT characteristic of the symptomatic phase of HIV?

Weight gain Signup and view all the answers

During which phase of HIV infection does a significant loss of memory CD4+ cells occur?

Acute infection phase Signup and view all the answers

What is a common mechanism by which HIV initially attaches to cells?

Attachment to dendritic cells Signup and view all the answers

What happens to the viral phenotype in approximately 50% of late-stage HIV infection cases?

It switches from R5 to X4 Signup and view all the answers

Why is constant monitoring necessary for drug treatments of HIV?

To prevent viral mutations Signup and view all the answers

What immune response is primarily attempted during the chronic phase of HIV infection?

Recovery of CD4+ T cells Signup and view all the answers

What is a common result of mutations in HIV’s immunogenic epitopes?

Formation of escape mutants Signup and view all the answers

What role does glycosylation play in the context of HIV?

It occludes epitopes on gp120 and gp41. Signup and view all the answers

How do CCR5-Δ32 mutations affect susceptibility to HIV?

Homozygotes are resistant to HIV infection. Signup and view all the answers

What is the effect of mutations in viral protease and Tat on HIV fitness?

They can lead to loss of viral fitness. Signup and view all the answers

Which HLA-B alleles are associated with delayed progression to AIDS?

HLA-B57 and HLA-B27 Signup and view all the answers

What key treatment strategy is referred to as HAART?

A highly active antiretroviral therapy. Signup and view all the answers

What was one unique outcome for Timothy Ray Brown following his stem cell transplant?

He was cured of HIV. Signup and view all the answers

What impact do escape mutants have during HIV infection?

They can avoid presentation by MHC class I. Signup and view all the answers

What happens to HIV replication in resting T cells?

It does not replicate. Signup and view all the answers

Study Notes

Immunodeficiency Overview

Immunodeficiency encompasses conditions where the immune system is weakened, making individuals susceptible to infections.
Two main types exist: primary (inherited) and secondary (acquired).
Primary immunodeficiencies manifest at birth or early childhood, usually stemming from genetic defects impacting immune cell development or function.
Secondary immunodeficiencies arise later in life, often due to underlying diseases like HIV/AIDS, malnutrition, or certain medications.

Learning Objectives

The videos cover examples of primary and secondary immunodeficiencies, their underlying causes, and manifestations.
Basic detection, monitoring, and treatment strategies/plans for these conditions are also addressed.
By the video's end, students should be able to detail the causes of both primary and secondary immunodeficiencies and how these lead to immune dysfunction.
Laboratory investigation methods used in diagnosing and monitoring the conditions are also to be understood.

Primary Immunodeficiency

Classification is based on the specific immune components affected: phagocytes, complement, B lymphocytes (humoral immunity), T lymphocytes (cell-mediated immunity), and combined B and T cell defects.
Primary immunodeficiencies are often characterized by frequent and prolonged infections, presenting in early childhood usually within 1-2 months of birth.
They are also associated with developmental delay (DD) or failure to thrive (FTT) and require medical interventions.

Primary Immunodeficiencies - Specific Conditions

Phagocyte dysfunction (Chronic Granulomatous Disease):
Early-onset recurrent infections, particularly fungal.
Normal antibody and complement responses, but impaired phagocyte function.
Dysfunction in genes for oxidative burst.
Complement abnormalities (Complement Deficiencies):
Characterized by recurrent infections.
Often results in increased susceptibility to severe bacterial infections and developmental delay.
B lymphocyte defects (XLA):
X-linked agammaglobulinemia; deficiency of Bruton's tyrosine kinase.
Characterized by a decrease in B cells and gamma globulin.
Patients prone to recurrent bacterial infections and often diagnosed in childhood.
T lymphocyte cell-mediated immunity (CMI) defects (DiGeorge Syndrome):
Recurrent serious viral, bacterial, and fungal infections, including failure to thrive and developmental delay.
Associated with impaired T cell function and anatomical abnormalities, including cardiac issues.
Often diagnosed by the absence or underdevelopment of the thymus.
Combined B and T cell deficiencies (SCID):
Severe combined immunodeficiency; marked immune deficiency impacting both B and T cells.
Characterized by severe recurrent infections and failure to thrive.
This often necessitates a stem-cell transplant for a cure.

Treatments

Stem cell transplantation: Replaces faulty immune cells with healthy ones.
Risk and benefit ratio—critical to understanding the choice of therapy.

Secondary Immunodeficiency

Causes of secondary immunodeficiency: Immunosuppressive drugs, malnutrition, HIV, and various health conditions.
HIV (Human Immunodeficiency Virus):
Characterized by gradual destruction of CD4+ T cells.
Leads to progression from acute (initial) infection, through an asymptomatic phase, and eventually to AIDS (Acquired Immunodeficiency Syndrome).

HIV Infection Timeline

Includes stages of acute infection (flu-like), asymptomatic, symptomatic (non-specific symptoms), and finally progressing to AIDS.
CD4+ T-cell count decrease correlates with the progression of disease.
The initial infection usually establishes in genital/anal mucosa and moves to lymphoid tissues and cells for viral replication.

HIV Genes & Replication

HIV's genetic material, RNA is converted into DNA by reverse transcriptase.
The newly created DNA integrates into the host cell's DNA, creating a provirus leading to continuous HIV replication.
HIV primarily targets Helper T cells (CD4+ T-cells) and, macrophages, and dendritic cells.
Viral proteins such as gp120, gp41 and others allow entry, fusion in the host cell and replication.

HIV Treatment (HAART)

HAART (Highly Active Antiretroviral Therapy) aims to reduce viral load and protect CD4 counts, often with mixed success due to drug resistant mutants.
Antivirals can target specific stages of HIV replication such as entry, replication and budding.

Summary

The presentation covers primary immunodeficiencies (inherited).
Also includes details regarding secondary immunodeficiencies like HIV and the pathogenesis and treatment (HAART).
Various factors that can affect the immune response to infections and the progression to immunodeficiency disorders like HIV are discussed.

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Description

Test your knowledge on primary immunodeficiencies, including their symptoms, classifications, and treatment options. This quiz covers essential concepts relevant to immunodeficiency disorders as they occur in infants and children. Brush up on key details to better understand immunology in clinical practice.