The Jeffrey Modell Foundation created the 4 Stages of Testing Poster in the 1990s to assist physicians in making a Primary Immunodeficiency diagnosis. The poster has been translated into more than 50 languages to help diagnose patients across the world!

Stage 1

  • History and physical examination
  • CBC and differential
  • Quantitative Immunoglobulin levels IgG, IgM, IgA 1 

Stage 2

  • Specific antibody responses (tetanus, diphtheria, pneumococcus)
  • Lymphocyte surface markers CD3/CD4/CD8/CD19/CD56 

Stage 3

  • Lymphocyte proliferation studies (mitogen/antigen stimulation or skin delayed type hypersensitivity)
  • Neutrophil oxidation burst (if indicated)
  • Response to pneumococcal vaccine (for ages 3 and up)
  • Primary Immunodeficiency gene sequencing panel 

Stage 4

  • Complement screening CH50, specific complement components, AH50
  • Enzyme activity measurements (e.g., adenosine deaminase, purine nucleoside phosphorylase)
  • Phagocyte studies (e.g., surface glycoproteins, mobility, phagocytosis)
  • NK cytotoxicity studies
  • Neo antigen response to test antibody production
  • Other surface molecules for detailed immunophenotype (e.g., memory B cells, T/NK cell subpopulations)
  • Specific protein levels (e.g., SAP, Perforin, WASp)
  • Cytokine or other function receptor quantification
  • IgG subclass analysis
  • Genomic studies

To read the 4 Stages poster in additional languages, click here: http://info4pi.org/library/educational-materials/10-warning-signs-international.