LFA-1 Intergrin Defect!
An infant boy has recurrent pneumonia and gingivitis. He is found to have a white count of 75,000 cells/mm3 and a defect in LFA-1 integrin. What is his most likely diagnosis?
A. Severe Combined Immunodeficiency
B. Chediaki-Higashi disease
C. Chronic granulomatous disease
D. Job’s Syndrome
E. Leukocyte adhesion deficiency type I
answer is E
The prominent clinical feature of these patients
is recurrent bacterial infections, primarily
localised to skin and mucosal surfaces.
Infections are usually apparent from birth
onward, and a common presenting infection is
omphalitis with delayed separation of the
umbilical cord. The absence of pus formation at
the sites of infection is one of the hallmarks of
LAD I. Severe gingivitis and periodontitis are
major features among all patients who survive
infancy. Impaired healing of traumatic or surgical
wounds is also characteristic of this syndrome
. The severity of clinical infectious
complications among patients with LAD I
appears to be directly related to the degree of
Affected children are born after uneventful
pregnancies with normal height and weight. No
delay in the separation of the umbilical cord is
observed. Affected individuals have the rare
Bombay (hh) blood phenotype. Later in life, they
show severe mental retardation, short stature,
and a distinctive facial appearance. Infections
are generally not life-threatening and are usually
treated in an out-patient clinic. There is no pus
formation at the site of infection. After the age of
3 years, the frequency of infections decreases
and children no longer need prophylactic
antibiotics . The hallmark of LAD II syndrome
is the deficiency in the expression of the sLe
antigen, the selectin ligand, on leukocytes.
) is a constant
finding . LAD II is also called congenital
disorder of glycosylation type IIc (CDG IIc)
Last edited by usmlemydream; 08-09-2011 at 01:48 AM. Reason: huk
I would go with Leukocyte adhesion deficiency, because its the integrin which is missing, so hence you can't adhere.
I honestly didn't know this disorder, but it makes the most sense.
SCID on the other hand is due to ADA deficiency
Set your mind to it, and you will be there.
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Leukocyte adhesion deficiency type 1 presents with bacterial infections in the neonatal period, including omphalitis, pneumonia, gingivitis, abscesses and peritonitis. It has a defect in LFA-1 integrin. Chediak-Higashi disease is an autosomal recessive disorder characterized by abnormal microtubule formation, affecting movement and membrane fusion of lysosomes. It is characterized by neutropenia, albinism, cranial and peripheral neuropathy and recurrent pyogenic infections by staphylococci and streptococci. Chronic granulomatous disease is an X-linked disorder characterized by deficient activity of NADPH oxidase with marked susceptibility to opportunistic infections, especially S. aureus, E. Coli and Aspergillus. Job’s syndrome is caused by failure of interferon gamma production by T helper cells. It presents with recurrent staphylococcal infections, eczema-like skin rashes and severe lung infections, resulting in pneumatoceles and elevated concentrations of serum IgE antibody. Severe Combined Immunodeficiency is caused by a defect in early stem cell differentiation, resulting in marked deficiency of both B and T cells.
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