Question

Peter was born after an uneventful pregnancy and weighed 3.1kg. At 3 months, he developed otitis media and an upper respiratory tract infection. At the ages of 5 months and 11 months, he was admitted to hospital with Hemophilus influenza pneumonia. The infections responded promptly to the appropriate antibiotics on each occasion. When 16 months old, he had a relapse of otitis media. He is the fourth child of unrelated parents: his three sisters show no predisposition to infection.

Examination at the age of 18 months showed a pale, thin child whose height and weight were below the third centile. There were no other abnormal features. He had been fully immunized as an infant (at 2, 3 and 4 months) with tetanus and diphtheria toxoids, whole-cell pertussis, Hemophilus vaccine and oral polio. In addition, he had received measles, mumps and rubella vaccine at 12 months. All immunizations were uneventful.

Immunological investigations (Table C3.1) into the cause of his recurrent infections are shown below. Both parents deny family history of immune system disorders. After carefully studying the laboratory results (presented below) the medical staff decided upon a diagnosis and began treatment. Over the following 2 years, his health steadily improved: his weight and height are now on the 10th centile, and he has had only one episode of otitis media in the last 18 months.

I don't expect you to know the name of the disease, but what is wrong here? What do you think could be done to help this child?

Laboratory Results for Baby Peter:  

Quantitative serum immunoglobulins (g/l)
IgG	0.17	[5.5-10.0]
IgA	Not detected	[0.3-0.8]
IgM	0.07	[0.4-1.8]
Antibody activity
Immunization responses
Tetanus toxoid - no detectable IgG antibodies
Diphtheria toxoid - no detectable IgG antibodies
Polio - no IgG antibodies detected
Measles - no IgG antibodies detected
Rubella - no IgG antibodies detected
Isohemagglutinins (IgM) not detected (blood group A Rh+)
Blood lymphocyte subpopulations (x109/l)
Total lymphocyte count	3.5	[2.5-5.0]
T lymphocytes (CD3)	3.02	[1.5-3.0]
B lymphocytes (CD23)	<0.03	[0.1-0.4]
(CD19)	<0.1	[0.3-1.0]
(CD20)	<0.1	[0.3-1.0]

*Normal range for age 18 months shown in brackets.

OK, now that all the lab results are in, venture a guess as to the name of this disease.  

Answer 1

From the above events and the lab reports It was found that Peter is deficient with IgA immunoglobulins.This condition is also known as Selective Immunoglobulin A deficiency i.e SIgAD as the normal range of IgA is found to be 0.3 to 0.8 but Peter is lab reports does not have IgA immunoglobulin. Also Peter have Influenza, Otitis Media, and also upper respiratory tract infections.

Immunogloglobulins : These are the antibodies which protects the body against disease causing organisms.

Type	Characteristics	Deficiency symptoms
IgA	Present larger amounts in breast milk, saliva and tears.Found in respiratory, mucus and digestive tracts	Sinus,lung and digestive infections, Ear infections, Eye infections, Pneumonia, Auto immune disorders, Asthma,Diarrhea and allergic reactions.
IgD	Larger amounts seen in chest and bellies	Abdominal pain, Diarrhoea, Joint infections, cold chills, head ache, lymphadenopathy, Hepatomegaly
IgE	People who have allergies contains highest amounts	Rhinitis, Asthma and Fatigue
IgG	Smallest immunoglobulin	Sinus and other respiratory tract infections, Pneumonia,Ear and Gastrointestinal infections,
IgM	Largest immunoglobulin which responds to infection and found in blood.	Repeated bacterial , viral and fungal infections leads to death.