IDC
NY 2011
NEW YORK — Infants with severe combined
immunodeficiency may appear healthy at birth, but have few T cells, leaving
them susceptible to recurrent and opportunistic infections, according to a
speaker here at the 24th Annual Infectious Diseases in Children
Symposium.
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Russell W.
Steele
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Health officials estimate severe combined
immunodeficiency (SCID) affects about one in 50,000 to 100,000 infants, but the
exact number is unknown due to a of lack specific diagnostic tools and an
incomplete understanding of the genetic interplay that results in symptoms.
Until recently, many infants with SCID went unrecognized until they developed
infectious complications due to their immune deficiency, according to
Russell W. Steele, MD, who is the division head of the pediatric
infectious diseases department at Ochsner Children’s Health Center in New
Orleans. “What I’d like to discuss is host factors that predispose
children to infectious diseases,” he said.
But recent recommendations from the Secretary’s
Advisory Committee on Heritable Disorders in Newborns and Children added SCID
to the uniform newborn screening panel, which will hopefully change the trends
of late diagnosis, according to Steele. “The intention of these
recommendations is to boost early detection of immunodeficiency to initiate
earlier treatments,” he said.
Early diagnosis
The Medical College of Wisconsin instituted universal
newborn screening, and researchers found that among 46 children in whom SCID
was diagnosed before 3.5 months of age, 96% survived 26 years after
transplantation vs. 66% of 116 children who did not receive an early diagnosis.
Steele said there are certain children who should be
evaluated for primary immunodeficiencies, including those patients with
quantitative immunoglobulins (IgG, A and M) and those patients whose disease is
affiliated with abnormal neutrophil function or cellular immune function.
Also, Steel said pediatricians should regularly consult
with those immunocompromised patients who are at risk for recurrent infections,
including patients with:
- Methicillin-resistant Staphylococcus aureus.
- Cancer
- Neonates
- AIDS
- Immunodeficiency
- Transplants
- Pulmonary disease
- Recurrent meningitis
- Recurrent abscesses
“Myeloperoxidase deficiency, which is biochemical,
may be the cause of recurrent MRSA abscesses,” Steele said, adding that
hyper IgE syndrome, chronic granulomatous disease and neutrophil adhesion may
be other causes of recurrent abscesses.
Steele said mupirocin (Bactroban Nasal, GlaxoSmithKline)
is a key treatment of recurrent MRSA. “We have found that the cream works
better than the ointment.” Other treatments include Clorox in the bath
water, clipping the child’s fingernails and covering the child’s
hands at night.
Risk profile
Steele said the definition of fever has remained the
same from previous guidelines, and children with cancer should be placed in
high-risk or low-risk groups. Children with prolonged or profound neutropenia
should be placed in the high-risk group and treated with empiric antibiotic
therapy.
“Cefepime wins the race this year,” he said.
“Also in the running is carbapenems, including meropenem or
imipenem-cilastatin”
Piperacillin-tazobactam are recommended empiric
antibiotics for this group, according to Steele. “Vancomycin is not
recommended, except in cases of catheter-related infection, skin or soft-tissue
infection, pneumonia or hemodynamic instability,” he said.
Steele discussed a broad, comprehensive range of
recurring infections — from Candida to MRSA to otitis media —
which may indicate a primary immunodeficiency. “It’s almost every
pathogen that we come across,” he said. “However, the type of
infection that patients have had will lead us to look strongly at one
compartment of immunity or another.”
Disclosure: Dr. Steele reports being on the
speakers’ bureaus, which are paid directly to his institution, for the
American Academy of Pediatrics, American College of Physicians, Sanofi-Pasteur,
Merck, GlaxoSmithKline, Pfizer, Roche, Abbott and MedImmune.
For more information:
- Steele RW. Evaluation of immunodeficiencies. Presented at: the 24th
Annual Infectious Diseases in Children Symposium; Nov. 18-20, 2011; New
York.