Pediatric Wiskott-Aldrich Syndrome Medication

Otitis media is treated with conventional first-line antibiotics (eg, amoxicillin, amoxicillin/clavulanate, cefuroxime axetil). Intramuscular injection of antibiotics is avoided because of the risk of excessive bleeding. The duration of antibiotic therapy should follow conventional recommendations for the specific infection being treated.

Most medical care is provided on an outpatient basis with the caveat that episodes of bacteremia and sepsis present higher risks for patients with Wiskott-Aldrich syndrome (WAS), and signs and symptoms may be subtle because of an inadequate inflammatory response resulting from phagocytic and humoral immune defects.

Administration of tetanus and diphtheria toxoids and the acellular pertussis and conjugated Hib and pneumococcal vaccines is essential and usually results in a protective, although subnormal, antibody response. The attenuated varicella vaccine has been administered without complication. Live measles and poliovirus vaccines are contraindicated. Influenza and hepatitis vaccines should be safe, but experience in administering them to patients with Wiskott-Aldrich syndrome is limited.

IVIG has been administered to selected patients with frequent bacterial infections.

Some patients may benefit from conventional inhaler therapies for reactive airway disease.

Replacement therapy with intravenous immunoglobulin in patients with primary immune deficiencies

The consensus among clinical immunologists is that a dose of intravenous immunoglobulin (IVIG) of 400-600 mg/kg/mo or a dose that maintains trough serum immunoglobulin G (IgG) levels greater than 500 mg/dL is desirable. Patients with meningoencephalitis require much higher doses (1 g/kg) and perhaps intrathecal therapy. Measurement of preinfusion (trough) serum IgG levels every 3 months until a steady state is achieved and then every 6 months if the patient is stable may be helpful in adjusting the dose of IVIG to achieve adequate serum levels. For persons who have a high catabolism of infused IgG, more frequent infusions (eg, every 2-3 wk) of smaller doses may maintain the serum level in the reference range. The rate of elimination of IgG may be higher during a period of active infection; measuring serum IgG levels and adjusting to higher dosages or shorter intervals may be required.

For replacement therapy for patients with primary immune deficiency, all brands of IVIG are probably equivalent, although differences in viral inactivation processes are noted (eg, solvent detergent versus pasteurization and liquid versus lyophilized). The choice of brands may depend on the hospital or home care formulary and the local availability and cost. The dose, manufacturer, and lot number should be recorded for each infusion in order to review for adverse events or other consequences.

Recording all side effects that occur during the infusion is crucial. Monitoring liver and renal function test results periodically, approximately 3-4 times yearly, is also recommended. The US Food and Drug Administration (FDA) recommends that for patients at risk for renal failure (eg, preexisting renal insufficiency, diabetes, volume depletion, sepsis, paraproteinemia, age >65 y, use of nephrotoxic drugs), recommended doses should not be exceeded and infusion rates and concentrations should be the minimum levels that are practicable.

The initial treatment should be administered under the close supervision of experienced personnel. The risk of adverse reactions in the initial treatments is high, especially in patients with infections and those who form immune complexes. In patients with active infection, infusion rates may need to be slower and the dose halved (ie, 200-300 mg/kg), with the remaining dose administered the next day to achieve a full dose. Treatment should not be discontinued. After achieving reference range serum IgG levels, adverse reactions are uncommon unless patients have active infections.

With the new generation of IVIG products, adverse effects are much reduced. Adverse effects include tachycardia, chest tightness, back pain, arthralgia, myalgia, hypertension or hypotension, headache, pruritus, rash, and low-grade fever. More serious reactions are dyspnea, nausea, vomiting, circulatory collapse, and loss of consciousness. Patients with more profound immunodeficiency or patients with active infections have more severe reactions.

Anticomplementary activity of IgG aggregates in the IVIG and the formation of immune complexes are thought to be related to the adverse reactions. The formation of oligomeric or polymeric IgG complexes that interact with Fc receptors and trigger the release of inflammatory mediators is another cause. Most adverse reactions are rate related. Slowing the infusion rate or discontinuing therapy until symptoms subside may diminish the reaction. Pretreatment with ibuprofen (5-10 mg/kg every 6-8 h), acetaminophen (15 mg/kg per dose), diphenhydramine (1 mg/kg per dose), and/or hydrocortisone (6 mg/kg per dose, maximum 100 mg) 1 hour before the infusion may prevent adverse reactions. In some patients with a history of severe adverse effects, analgesics and antihistamines may be repeated.

Acute renal failure is a rare but significant complication of IVIG treatment. Reports suggest that IVIG products using sucrose as a stabilizer may be associated with a greater risk for this renal complication. Acute tubular necrosis, vacuolar degeneration, and osmotic nephrosis are suggestive of osmotic injury to the proximal renal tubules. The infusion rate for sucrose-containing IVIG should not exceed 3 mg sucrose per kg/min. Risk factors for this adverse reaction include preexisting renal insufficiency, diabetes mellitus, dehydration, age older than 65 years, sepsis, paraproteinemia, and concomitant use of nephrotoxic agents. For patients at increased risk, monitoring BUN and creatinine levels before starting the treatment and prior to each infusion is necessary. If renal function deteriorates, the product should be discontinued.

Immunoglobulin E (IgE) antibodies to immunoglobulin A (IgA) have been reported to cause severe transfusion reactions in IgA-deficient patients. A few reports suggest true anaphylaxis in patients with selective IgA deficiency and common variable immunodeficiency who developed IgE antibodies to IgA after treatment with immunoglobulin. However, in actual experience this is very rare. In addition, this is not a problem for patients with X-linked agammaglobulinemia (XLA) (Bruton disease) or severe combined immunodeficiency (SCID). Exercise caution in patients with IgA deficiency (< 7 mg/dL) who need IVIG because of IgG subclass deficiencies. IVIG preparations with very low concentrations of contaminating IgA are advised (see the Table below).

Table. Immune Globulin, Intravenous^{[29, 30, 31, 32]} (Open Table in a new window)

Class Summary

Amoxicillin, amoxicillin/clavulanate, and cefuroxime axetil are the PO drugs of choice for the common extracellular bacteria that cause sinopulmonary infections. Ceftriaxone administered intravenously is the first-line antibiotic for suspected bacteremia or sepsis and for pneumonia. It covers penicillin-resistant pneumococci. Intramuscular administration is avoided because of bleeding caused by thrombocytopenia. Nafcillin is chosen for invasive S aureus. Vancomycin is needed for penicillin-allergic patients and for treatment of methicillin-resistant S aureus. Vancomycin-resistant S aureus, GISA, may require fluoroquinolones, linezolid or Synercid.

Prophylactic antibiotics for patients with splenectomies are penicillin or amoxicillin; a macrolide can be used for penicillin-allergic patients.

Amoxicillin (Trimox, Amoxil, Biomox)

Interferes with synthesis of cell wall mucopeptides during active multiplication, resulting in bactericidal activity against susceptible bacteria.

Amoxicillin/clavulanate (Augmentin)

Drug combination treats bacteria resistant to beta-lactam antibiotics.

For children >3 mo, base dosing protocol on amoxicillin content. Because of different amoxicillin–clavulanic acid ratios in 250-mg tab (250/125) vs 250-mg tab (250/62.5), do not use 250-mg tab until child weighs >40 kg.

Cefuroxime axetil (Ceftin)

Second-generation cephalosporin maintains gram-positive activity that first-generation cephalosporins have. Adds activity against Proteus mirabilis, H influenzae, E coli, K pneumoniae, and Moraxella catarrhalis.

Ceftriaxone (Rocephin)

Third-generation cephalosporin with broad-spectrum activity; efficacy against resistant organisms. Arrests bacterial growth by binding to one or more penicillin-binding proteins.

Vancomycin (Lyphocin, Vancocin, Vancoled)

Potent antibiotic directed against gram-positive organisms and active against Enterococcus species. Indicated for patients who cannot receive or who have not responded to penicillins and cephalosporins or who have infections with resistant staphylococci.

To avoid toxicity, current recommendation is to assay vancomycin trough levels after third dose drawn 0.5 h before next dosing. Use creatinine clearance to adjust dose in patients with renal impairment.

Nafcillin

DOC for acute pneumonia and deep-seated abscesses caused by S aureus.

Class Summary

These agents are used to relieve bronchoconstriction and decrease the inflammatory response in the respiratory tree. Both pulmonary and nasal inhalers may be needed. Children 4 years and older may use inhalers effectively. Inhaler use is hampered in young children and others unable to understand the technique of administration and in older individuals unable to achieve a forceful inhalation. Adding a spacer is customary to improve coordination in children. Steroid inhalation is followed by rinsing the mouth to avoid thrush, and a spacer is highly recommended for use with steroid pressurized metered dose inhalers for all patients.

Albuterol (Proventil HFA, Ventolin HFA)

Relaxes bronchial smooth muscle by action on beta2-receptors with little effect on cardiac muscle contractility.

Salmeterol (Serevent Diskus)

By relaxing the smooth muscle fibers of the bronchioles it can relieve bronchospasms. Effect may also facilitate expectoration.

Beclomethasone (QVAR)

Inhibits bronchoconstriction mechanisms and produces direct smooth muscle relaxation. May decrease number and activity of inflammatory cells, in turn decreasing airway hyperresponsiveness.

Some patients may require higher doses of inhaled beclomethasone. Available as 40-mcg and 80-mcg per inhalation.

Fluticasone (Flovent HFA)

Has extremely potent vasoconstrictive and anti-inflammatory activity. Has a weak hypothalamic-pituitary-adrenocortical axis inhibitory potency when applied topically.

Some patients may require higher doses of inhaled fluticasone.

Class Summary

A limited number of immunoglobulin preparations have been developed to provide prophylaxis against specific microorganisms. For primary immunodeficiency diseases including Wiskott-Aldrich syndrome, VZIG has proven efficacy to prevent primary varicella when administered within 48-72 hours postexposure. It may modify varicella when administered up to 96 hours later.

Varicella-zoster immune globulin (VariZIG)

Contains IgG varicella-zoster antibodies. Provides passive immunization to exposed individuals at high risk of complications from varicella. Administration recommended within 48 h postexposure but may be efficacious up to 96 h postexposure. The US product VZIG was discontinued by the manufacturer. An investigational product (VariZIG) is currently available via IND (contact FFF Enterprises at 800-843-7477).

Class Summary

Vaccines that contain viral components (not live viruses) should be administered to patients with Wiskott-Aldrich syndrome because a protective antibody response is often obtained. Injection technique is critical because of the risk of bleeding and hematoma at the injection site. Live virus vaccines are contraindicated with the possible exception of varicella-zoster virus. For current Advisory Committee on Immunization Practices (ACIP) recommended immunizations schedule for immunocompromised individuals, see the Centers for Disease Control and Prevention (CDC) guidelines.^{[33, 34]}

Vaccines

Diphtheria and tetanus toxoids (DT or Td), acellular pertussis, conjugated HIB, conjugated pneumococcal vaccine, unconjugated meningococcal A and C, hepatitis B (HBV), and influenza. CDC/AAP recommendations undergo continuing reevaluation.