1. Immune Work-Up for the General Pediatrician
Fatima Gutierrez M.D.

2. Goals and objectives Learn when to Suspect an Immune Deficiency
Important Aspects of History Taking
Physical Exam Clues
Initial Laboratory Work-up
When to get an Immune Consult
Overview of Specialized Tests

4. When to suspect: 8 or more new ear infections within one year
2 or more serious sinus infections within 1 year
Two or more months on antibiotics with little effect
2 or more pneumonias within 1 year
Failure of an infant to gain weight or grow normally

5. When to suspect Recurrent, deep skin or or organ abscesses
Persistent thrush in mouth or elsewhere on skin, after age 1
Need for IV antibiotics to clear infections
2 or more deep-seated infections
Family history of Primary Immunodeficiency

7. Zebras among us Sinusitis/Pneumonia Low Antibody levelsCF
Allergic Rhinitis
Anatomy
Low Antibody levels
Protein-losing entropathy, nephropathy
Severe eczema
Burns
2° Immunodeficiency
Malnourishment
Diabetes
Sickle Cell

8. Basic immunology
Primary Immunodeficiencies Can Be Categories by their Defect:
Cellular Immunity (T-Cells)
Humoral Immunity (B-Cell)
Phagocytes
Complement

9. T- cells Plasma cells Immunoglobulins B-lymphocytes Bone Marrow
Stem Cell
T- cells

10. T-Cell Defects T-Cells directly Attack Foreign Antigens
Opportunistic infections
Candida sp, Pneumocystis jiroveci
Persistent Thrush
Diarrhea/Malabsorption
Poor Growth/Failure to Thrive

11. B-Cell Defect Unable to make specific antibodies
Multiple / Severe Bacterial Infections
Persistent Upper Respiratory Tract Infections
Streptococcus, Haemophilis
Usually seen after 6 months when maternal antibodies lost
Growth usually normal unless patient with chronic infections

12. Phagocyte defects
Natural Killer Cells – directly attack cells infected with Virus
Phagocytes – ingest and kill microorganisms
Chronic Granolomatous Disease –
- Infections caused by catalase + organisms
LAD No Pus
Gingivitis/Periodontitis
Skin Infections, Liver, GI Tract

13. Complement defects Composed of 30 proteins
Function in ordered integrated fashion to defend against infection and produce inflammation
C5- C8 deficiency associated with autoimmune
C1-C4 deficiency
Associated with Rheumatic Disorders
Pyogenic Infections
C5-C9 Complement deficiency
Neiserria Infections
Basic Screen – CH50 – measures function of alternate pathway

14. Stats: Immunodeficiency Primary Secondary 1:500 – 1:100,000 - All
1:500 IgA def
1:100,000 SCID
1:200,000 CGD
Secondary
1:300 - HIV
1:5 “unaware” of their HIV

16. Stage 1: History & Exam History Infection History Sex Consanguinity
History of Miscarriage/ Death in Infants
Primary Immune Deficiency in Family
History of Autoimmune/Connective Tissue d/o
Environment (Smoke, allergies)
Delayed Cord Separation (LAD)
HIV risk factors
Passive cigarrette smoke inhalation can predispose to otitis media, pneumonia, bronchitis.
Allerigies can worsen congestion, predispose to sinusitis and otitis media

17. Physical exam Eczema , Wiskott Aldrich or Hyper IgE? Wiskott Aldrich
Thrombocytopenia
Small platelets
Hyper IgE -Job Syndrome
Skin infections – Staph
Sinusitis
Coarse Facies
Retain Primary Teeth
Lack of tonsils/lymph nodes – X-linked aggamaglobulinemia
Lack of Pus- Leukocyte Adhesion Disorder
Chronic Eczema – Wiscott Aldrich, Hyper IgE

18. Physical Exam:
Conical Teeth
Look at Mother
Incongentia Pigmenti

19. NemO: Not just a fish Nuclear Factor – kB Essential Modulator X-Linked
Defect in Cellular Immunity
Variable Immunoglubulin levels
Normal B-cell numbers
Recurrent bacterial sinopulmonary and oportunistic Infections
Ectodermal Dysplasia
Conical Teeth
Treatment Stem Cell Transplant

20. STAGE 1: important info in the CBC
Lymphocyte count
Absolute Lymphocyte count
Lymphopenia
Screen for B and T cell Deficiencies
Lymphocytosis
Omenn Syndrome, Leukocyte Adhesion Deficiency
Neutrophil Count
Leukocyte Adhesion Deficiency - >100,000/mm3
Platelet Size and Number
Wiskott Aldrich

21. ALC below 2000 abnormal in Infants!
WBC total x %lymphocytes = Absolute Lymphocyte Count (ALC)
Normal absolute lymphocyte count 10th- 90th percentiles (#/μL) by age
0-3months
6-12months
1-2 years
Look at normal values based on Age!!

22. Stage 1: Immunoglobulins
IgG, IgM, IgA, IgE
IgG in young infants less reliable –largely maternal
Lab Variations! Age Adjusted Normals
Low IgG in Infant
Hypogammaglobulinemia of Infancy
Undetectable IgA
Primary Immune Deficiency
High Levels IgM + Absence of other Ig
Hyper IgM
IgE
Atopic Disease or Parasitic Illness, Hyper IgE

23. Immunoglobulin Development
IgG nadir for infants is age 3 months to 1 year of life
Premature infants will lack adequate maternal IgG
Note in IgG at approximately 6 months of life (maternal vs infant sources)
IgM production starts immediately after birth
IgA rate of synthesis is slowest

24. X-Ray THYMUS! May shrink in response to stress/surgery/infe ction
Thymus continues to grow until teens
Largest size relative to body weight at birth
No Thymus

25. DelayeD Hypersensitivity SkIN Test
T-cell Response
Common Antigens
Candida
Trychophyton
Tetanus
Diphtheria
PPD
Anergy (no response)
Immune suppr. Meds- Steroids
Infants < 6 months / 2yrs
Malnutrition
Collagen Vascular Disease
Fever- Leukocytosis
Reaction measured at 48 hours
High False negative

26. HIV TestIng HIV – DNA when IgG unreliable ELISA tests IgG
Infants have Maternal IgG
Severe Hypogammaglobulinemias
Liver Disease
Guidelines :

27. Abnormal Labs or Concerning clinical Picture: Immunology consult

28. Measurement of Specific T, B, NK and phagocytic cells
Phenotyping
Measurement of Specific T, B, NK and phagocytic cells

30. Lymphocyte studies

31. The Case of SCID
NK Cells
Tcells-
B-Cells

32. 4 fold increase of baseline 1 month after vaccine given
Humoral Immune Panel
Tests your Body’s Ability to Make Antibodies – Majority of Vaccines activate B-cells in the presence of T-cell
Tests for Common Vaccines
Diphtheria
Tetanus
Streptococcus
Majority of Vaccines T-Dependent
Normal Response
Diphtheria > 0.1
Tetanus > 0.1
Or…
4 fold increase of baseline 1 month after vaccine given

33. Humoral Immune Panel Streptococcus – Note minimal response
Serotypes in Prevnar:
4, 6B, 9V, 14, 18C, 19F, 23F
Serotypes in PCV13
Serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 23F
Test not accurate if patient received IVIG (Wait 3-4 weeks)
Bacteriophage X1074 if patients have recenlty received IVIG

34. lymphocyte proliferation Assays: (Mitogens and Antigens)
Measures the ability of lymphocytes to respond to mitogens and Specific antigens
Strongly Mitogenic on T-Cells
- PHA (Phytohemagluttin)
- ConA (Concanavalin-A)
Stimulates T&B cells (Mitogen
- Pokeweed
Minimal Response
Assay working well
Phytohemagluttin- isolated from red kidney bean
ConA- from jack beans
Pokeweed mitogen from root
Antigens:
- Candida
-Tetanus
- Dipthera
*Prior exposure required for response !! > 2yrs age

35. Take Home message
Early Recognition of Primary Immune Deficiency – Many Primary Immune Deficiencies are Lethal!
Recognize Lab Value Diversity
Don’t forget to look for HIV

36. References
Noroski MD, L., Shearer MD, W. Short Screening for Primary Immunodeficiencies in the Clinical Immunology Laboratory. Clinical Immunology and Immunopathology. Vol. 86, No3, March pp , 1998
Fleisher, Shearer, Kotzin, Schroder. Clinical Immunology – Principles and Practice 2nd Ed. Rich, R.
Schmitz PhD, Folds PhD. Clinical and Laboratory Assesment of Immunity. Journal of Allergy and Immunology 2003: 111:S702-11
American Academy of Allergy Asthma and Immunology – www. aaai.org
Immune Deficiency Foundation – primaryimmune.org
Jeffrey Modell Foundation www. jfmworld.org