Recurrent Streptococcus pneumoniae or Haemophilus influenzae infections

Ig, C2, or IRAK-4 deficiency

Recurrent Giardia intestinalis (lamblia) infection

Antibody deficiency syndromes

Familial clustering of autoimmune disorders (eg, SLE, pernicious anemia)

Common variable immunodeficiency or selective IgA deficiency

Pneumocystis infections, cryptosporidiosis, or toxoplasmosis

T-cell disorders or occasionally Ig deficiency

Viral, fungal, or mycobacterial (opportunistic) infections

T-cell disorders

Clinical infection due to live-attenuated vaccines (eg, varicella, polio, BCG)

T-cell disorders

Graft-vs-host disease due to blood transfusions

T-cell disorders

Staphylococcal infections, infections with gram-negative organisms (eg, Serratia or Klebsiella), or fungal infections (eg, aspergillosis)

Phagocytic cell defects or hyper-IgE syndrome

Skin infections

Neutrophil defect or Ig deficiency

Recurrent gingivitis

Neutrophil defect

Recurrent neisserial infections

Certain complement deficiencies

Recurrent sepsis

Certain complement deficiencies, hyposplenism, or IgG deficiency

Family history of childhood death or of infections in a maternal uncle that are similar to those in the patient

X-linked disorders (eg, severe combined immunodeficiency, X-linked agammaglobulinemia, Wiskott-Aldrich syndrome, hyper-IgM syndrome)