Acquired immunodeficiency

Clinical Manifestations

Immune Defect	Typical Infections	Typical Organisms
cell-mediated (T cells)	persistent viral infections, opportunistic infections, disseminated infections	Pneumocystis jirovecii, Cryptococcus, Herpesviridae
humoural (B cells)	respiratory infections with encapsulated organisms, chronic diarrhea, aseptic meningitis	Haemophilus influenzae, Streptococcus pneumoniae, Giardia lamblia, Campylobacter species, enteroviruses
phagocytic	recurrent abscesses, gingivitis, aphthous ulcers	Staphylococcus aureus, Burkholderia cepacia, Serratia marcescens, Aspergillus species, Nocardia species
monocytic	disseminated infections and multifocal osteomyelitis	non-tuberculous mycobacteria, Salmonella species, Histoplasma capsulatum, Coccidioides immitis
TLR	recurrent meningitis, bacteremia, absence of fever	Streptococcus pneumoniae, Neisseria meningitidis, Staphylococcus aureus, HSV
complement	recurrent bacteremia and meningitis	Neisseria species
T cells and phagocytes	eczema, kyphoscoliosis, pathologic fratures, pulmonary and cutaneous infections, mucocutaneous candidiasis	Staphylococcus aureus, Haemophilus influenzae, Streptococcus pneumoniae, Candida albicans

Differential Diagnosis

Cell-Mediated Immunodeficiency

• Corticosteroids
• Solid organ transplantation
• Hematologic malignancy
  • Hairy cell leukemia
  • Acute T-cell leukemia
  • T-cell lymphoma
• Chemotherapy
  • Fludarabine
  • Ibrutinib
  • Alemtuzumab
• Human immunodeficiency virus

Humoural Immunodeficiency

• Splenectomy and asplenism
• Complement deficiency
• Common variable immunodeficiency
• Rituximab and other anti-CD20 therapy
• Multiple myeloma and chronic lymphocytic leukemia

Phagocytic Defect

• Corticosteroids
• Solid organ transplantation
• Neutropenia
• Myelodysplastic syndrome
• Acute myelogenous leukemia
• Allogeneic hematopoietic stem cell transplantation