What Should I Order for An Immune Workup?

Patient Presentation
A 3-year-old male came to the emergency department with sudden onset of a fever to 42° C and a rash that began about 1 hour previous.
The mother said that he had been well but suddenly felt very warm and she noticed a red rash on the trunk that seemed to be spreading to the face and extremities. He also seemed to be breathing faster.
The past medical history revealed that he had several ear infections and mother says he always seems to be coughing. His immunizations were current.
The family history was negative.
The review of systems was negative including upper respiratory tract symptoms, nausea, vomiting, diarrhea, dysuria, etc.
The pertinent physical exam showed a male who appeared toxic, flushed in the face and was crying but who appeared oriented. He had a heart rate of 164, respiratory rate of 48, blood pressure of 56/34, and a weight of 13 kg (10% percentile). Pulse oximeter was 94%.
Capillary refill was > 3 seconds. His skin had petechiae on the chest, abdomen, face, upper arms and legs and new lesions were appearing during evaluation, particularly in areas of trauma such as tourniquets and venipuncture sites.
His heart had a II/VI murmur, consistent with a flow murmur at the lower left sternal border radiating upward. Lungs had clear breath sounds.
Abdomen and genitourinary systems were negative.
The patient’s clinical course of presumed sepsis was made and the patient was immediately treated with intravenous fluids, oxygen, dopamine and ceftriaxone.
and the PICU was called.
The stat laboratory evaluation showed an arterial blood gas of 7.32/90/32/-15. The hemoglobin was 11.3 mg/dl, platelets were 118 x 1000/mm2, and white blood cells of 12.5 x 1000/mm2 with 40% polymorphonuclear cells and 0% bands.
Blood cultures, urine cultures and a chest radiograph were ordered.
The patient was transferred to the PICU and continued to deteriorate into a coma with hypotension, respiratory distress, spreading purpuric rash and disseminated intravascular coagulopathy. He required intubation and epinephrine and norepinephrine drips.
Cefotaxime and gentamicin were given. The chest radiograph showed clear lung fields but dextrocardia noted. The peripheral blood smear showed Howell-Jolly bodies.
Five hours later despite maximal blood pressure and ventilator management, the patient coded and resuscitation was unsuccessful.
The family refused an autopsy. Twelve hours after admission to the emergency room, the blood culture grew a Streptococcus species that was later confirmed as Streptococcus pneumoniae.
The diagnosis of sepsis secondary to Streptococcus pneumoniae was made. The possible diagnoses of situs inversus viscerum with functional asplenia, or possibly a complement deficiency and asplenia were considered as possible primary causes of the sepsis.

Children with immunodeficiencies can present in many ways including failure to thrive, weight loss, poor weight gain, diarrhea, cough, recurrent infections, unusual infection organisms, or unusual infection organ locations, and as in this case, sudden onset of an overwhelming infection.
There is no absolute indicator as to when a child should be evaluated for a potential immune problem but the following can be considered:

  • Systemic bacterial infections, 2 or more, e.g. sepsis, meningitis, deep abscess
  • Bacterial infections, 3 or more, e.g. draining otitis media
  • Upper respiratory infections, > 6-8 in one year
  • Recurrent infection of same organism, e.g. meningococcemia
  • Need for surgical treatment, e.g. drainage of abscess, lobectomy for chronic pneumonia
  • Failure to thrive, weight loss or growth retardation
  • Unusual infections, i.e. Pseudomonas carinii in a presumably normal child

A through history of all infections and family history of infection or death is important.
Physical examination should look at growth parameters, clues of allergies (eczema, allergic shiners, wheezing), lymph nodes including tonsillar tissue (absence may indicate B-cell dysfunction), cardiac murmurs (i.e. DiGeorge syndrome) and ataxia (i.e. ataxia-telangiectasia)

Learning Point
Specific testing for immune disorders depends on the constellation of findings especially in the history which is then influenced by the physical examination.
Testing usually includes general screening tests as well as more specific tests for various components of the immune system. Some testing is not easily available and may be expensive. Patient evaluation and interpretation of the testing may necessitate consultation with an immunologist or hematologist/oncologist who is familiar with and treats such patients.
Immunological testing may include (common screening tests are *) :

  • B-Cells
    • *Immunoglobulin levels (i.e. IgM, IgA, IgG)
    • *Antibody titres to vaccines previously given or isohemagglutinins
    • B-cell phenotyping by flow cytometry
  • T-Cells
    • Delayed hypersensitivity skin testing by intradermal injection of common antigens (i.e. candida)
    • T-cell phenotyping by flow cytometry
    • T-cell proliferation testing to mitogens
  • Complement
    • *CH50 (total hemolytic complement)
    • Assays of individual components of the classic and alternative pathways, C3, C4
  • Phagocytic disorders
    • Neutrophil phenotyping by flow cytometry
    • Respiratory burst activity
  • General tests
    • Complete blood count with differential and platelets, *absolute lymphocyte count, *absolute neutrophil count
    • Peripheral blood smear for Howell-Jolly bodies, *neutrophil morphology
    • *HIV
    • Sweat test
    • Allergen skin testing
    • Erythrocyte sedimentation rate

Questions for Further Discussion
1. List some primary B-cell immunodeficiency disorders.
2. List some combined immunodeficiency disorders.
3. What does a Howell-Jolly body look like?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Information prescriptions for patients can be found at MedlinePlus for these topics: Sepsis and Immune System Disorders.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

Rudolph CD, et.al. Rudolph’s Pediatrics. 21st edit. McGraw-Hill, New York, NY. 2003:791-793.

Fleisher TA. Back to basics: primary immune deficiencies: windows into the immune system.
Pediatr Rev. 2006 Oct;27(10):363-72.

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient managemnt plans are developed and carried out.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.

  • Systems Based Practice
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.

    Donna M. D’Alessandro, MD
    Professor of Pediatrics, Children’s Hospital of Iowa

    September 4, 2007