Common variable immunodeficiency




Common variable immunodeficiency

Immune system

General infections


Neonatal sepsis


Hypersensitivity reactions

Type I hypersensitivity

Food allergy



Type II hypersensitivity

Immune thrombocytopenic purpura

Autoimmune hemolytic anemia

Hemolytic disease of the newborn

Goodpasture syndrome

Rheumatic heart disease

Myasthenia gravis

Graves disease

Pemphigus vulgaris

Type III hypersensitivity

Serum sickness

Systemic lupus erythematosus

Poststreptococcal glomerulonephritis

Type IV hypersensitivity

Graft-versus-host disease

Contact dermatitis


Transplant rejection

Graft-versus-host disease

Cytomegalovirus infection after transplant (NORD)

Post-transplant lymphoproliferative disorders (NORD)


X-linked agammaglobulinemia

Selective immunoglobulin A deficiency

Common variable immunodeficiency

IgG subclass deficiency

Hyperimmunoglobulin E syndrome

Isolated primary immunoglobulin M deficiency

Thymic aplasia

DiGeorge syndrome

Severe combined immunodeficiency

Adenosine deaminase deficiency


Hyper IgM syndrome

Wiskott-Aldrich syndrome

Leukocyte adhesion deficiency

Chediak-Higashi syndrome

Chronic granulomatous disease

Complement deficiency

Hereditary angioedema


Immune system organ disorders


Ruptured spleen

Immune system pathology review

Blood transfusion reactions and transplant rejection: Pathology review

Immunodeficiencies: T-cell and B-cell disorders: Pathology review

Immunodeficiencies: Combined T-cell and B-cell disorders: Pathology review

Immunodeficiencies: Phagocyte and complement dysfunction: Pathology review


Common variable immunodeficiency


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USMLE® Step 1 questions

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High Yield Notes

10 pages


Common variable immunodeficiency

of complete


USMLE® Step 1 style questions USMLE

of complete

A 13-year-old girl is brought to her pediatricians office for evaluation of shortness of breath and cough. She has had two episodes of pneumonia over the last two years and an episode of bloody diarrhea six months ago requiring hospitalization. Two years ago, the patient was without any significant health complications. Her only past medical history is asthma. Family history is noncontributory. Her immunizations are up to date. Temperature is 38.7 C° (101.7 F°), pulse is 90/min, respirations are 25/min, and blood pressure is 100/60 mmHg. Height and weight are currently at the 5th percentile for age. Physical examination reveals faint rales over the right lower lung field. No enlarged lymph nodes are palpated on neck examination. Laboratory results are shown.

 Laboratory value  Result 
 Complete blood count 
 Hemoglobin  12  g/dL  
 Leukocyte count  10,100 /mm3 
 Platelet count  200,000/mm3 
IgG  250mg/dL 
 IgA  24 mg/dL 
 IgM  15 mg/dL 
 IgE  undetectable 
 CD4/CD8 ratio  2 (normal, 1-4) 

Chest x-ray reveals a right lower lobe infiltrate. Which of the following is the most likely diagnosis in this patient?  

External References

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Common variable immunodeficiency (CVID) p. 114


Common variable immunodeficiency (CVID) is an immune system disorder that impairs your ability to fight infection. It's characterized by low serum levels of all immunoglobulins. People with CVID may present with repeated infections, such as sinus infections, ear infections, pneumonia, and blood infections. They're also at higher risk for other problems, such as autoimmune diseases (diseases where the body mistakenly attacks its tissues), like autoimmune hemolytic anemia, and can also have cancer and gastrointestinal issues. CVID is diagnosed through blood tests through quantitative measurements of the immunoglobulins.


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