pediatricianroleinprimaryimmunodeficienc

Pediatrician's Role in Primary Immunodeficiency:

As a Primary care Pediatrician when ever a suspicion of PID comes to one's mind pay attention to following points:

Clinical Presentation:

Age of Presentation:

• • Children with T cell & Phagocytic defects present at < 5 mths of age

• Children with B cell defects present at > 5 mths of age as they are protected by maternally transmitted Immunoglobulins.

Sex:

• • Male: Immunodeficiency is more common in Males as a large no of Immune system related genes are on the X chromosome.

  • e.g. X Linked Agammaglobulinaemia

  • X linked SCID

  • X linked Lymphoproliferative disorder.

  • Properdin deficiency.

  • X linked Hyper IgM Syndrome.

• Wiskott Aldrich Syndrome, X Linked Thrombocytopenia.

Consanguinity:

• PID is more common among families with consanguinity

Family History:

Detailed family History of the index case is very important

• • Helps to identify the mode of transmission.

• May help in case transplantation is necessary.

Presenting Symptoms:

• • Predominantly Respiratory - B cell Defect

  • GI & Respiratory suggest - T cell defect.

  • Delayed seperation of umbilical cord, Skin and oral cavity infections suggest Phagocytic defect LAD (Leucocyte Adhesion Deficiency)

• Eczema, Thrombocytopenia suggest Wiskott Aldrich Syndrome.

Vaccination History:

• • BCG - cause disseminated BCGosis in SCID

• OPV - Vaccine associated Paralytic Poliomyelitis in X linked Agammaglobulinaemia.

On Physical Examination:

Weight:

• • FTT (Failure to Thrive) - Suggest T cell defect

• BCGosis or atypical Mycobacterial Infection in absence of FTT suggest defect in IL12/23-Interferon Gamma defect.

Sex: as Mentioned in History.

Tonsils & Lymphnodes:

• Absence of Tonsils, Lymphnodes strongly suggest for possibility of SCID (Severe Combined Immunodeficiency)

Oral Cavity Examination:

• Gingivitis, oral ulcerations suggest phagocytic defects.

Organomegaly:

• Seen in Hemophagocytic Lymphohistiocytosis

Hair:

• • Silvery gray hair suggest Griscelli Syndrome.

• Hypopigmentation of Hair Chediak Higashi Syndrome.

Skin:

• • Albinism

• Features of Graft Versus Host Disease.

BCG Scar:

• presence of a large scar, nodule or ulcer formation suggest possibility of SCID

Investigations:

CBC Platelets:

Neutrophils:

• • Neutropenia may suggest Congenital Neutropenia.

  • Persistent Neutrophilic Leucocytosis Suspect LAD (Leucocyte Adhesion Deficiency

  • Absence of granules in PS suggest possibility of congenital absence of primary granules.

  • Presence of Large granule suggest possibility of Chediak Higashi Syndrome.

Pancytopenia:

• • Pancytopenia suggest possibility of HLH ( Hematophagic Lymphohistiocytosis)

Lymphocytes:

• • Always Calculate Absolute Lymphocyte count (ALC)

  • ALC is calculated by

  • WBC count x Lymphocyt %

  • -----------------------

  • 100

  • Lymphopenia ALC (Absolute Lymphocyte count) < 4000 in infancy or ALC < for age is Suggestive of SCID.

• Lymphopenia is a Hall Mark of SCID and it is a Pediatric Emergency, So refer urgently to an appropriate referral centre; Immediately.

"Always Calculate Normal Values for Age"

Xray Chest:

• • Look for presence or Absence of Thymus

• If Thymus is Absent it suggest possibility of SCID.

Appropriate Microbial Cultures:

• Always Send appropriate cultures depending upon site of involvement as this would help us understand which arm of the immune system is affected also it will help us learn sensitivity pattern of the organism and help decide line of treatment.

Pay attention to Skin and Hair changes in PID:

Treatment:

A pediatrician should refer a suspected case of Immunodeficiency to Referral Centre.

Vaccination:

• Avoid Live Vaccination in a child with Suspected Immunodeficency.

Transfusion of Blood or Blood Product:

• • Avoid Transfusion in case of suspected Immuodeficiency.

  • Use Irradiated CMV Negative Blood or Blood Products Only.

• Unirradiated Blood or Blood product could lead to Transfusion associated graft vs Host Disease. (TAGvHD).

Counselling of Family:

• • Please provide for Genetic Counselling in case of Confirmation of Primary Immunodeficiency.

• Do NOT Vaccinate The Next Sib till you have conclusively ruled out PID.

SCID can be suspected easily by paying attention to "Absolute Lymphocyte count".

Pediatrician can play a positive role in identifying a case as one of Primary Immunodeficiency and help counsel he family and can help most by avoiding live vaccination and Blood and Blood Product Transfusion without irradiating them.

"Refer Early to a specialised centre for Primary Immunodeficiency. "