Gastrointestinal bleeding
GI bleeds are unusual compared with those associated with von Willebrand disease
and, therefore, require an evaluation for an underlying cause. Manage GI
hemorrhage with repeated or continuous infusions to maintain nearly normal
circulating levels of FVIII.
Intracranial bleeding
Intracranial hemorrhage is often trauma induced; spontaneous intracranial
hemorrhages are rare. If CNS hemorrhage is suspected, immediately begin an
infusion prior to radiologic confirmation. Maintain the factor level in the normal
range for 7-10 days until a permanent clot is established.
All head injuries must be managed with close observation and investigated by
imaging such as CT scanning or MRI. If the patient is not hospitalized, instruct the
patient and his or her family regarding the neurologic signs and symptoms of CNS
bleeding so that the patient can know when to return for reinfusion.
Treatment of Patients with Inhibitors
Inhibitors are antibodies that neutralize factor VIII and can render replacement
therapy ineffective. They are found more commonly in patients with moderate to
severe hemophilia (up to 30% of those with severe disease) who have received
significant amounts of replacement therapy. Inhibitors develop in relatively young
children, usually within their first 50 exposures to FVIII.
Rarely, inhibitors can develop in individuals without hemophilia (eg, elderly
persons, pregnant women); these occasionally are responsive to
immunosuppressive therapy (eg, prednisone).
In a 2013 study of 574 consecutive patients with severe hemophilia A (FVIII
activity, < 0.01 IU/mL), 177 of whom developed inhibitors, the risks of inhibitor
development were found to be similar with recombinant and plasma-derived factor
VIII products, and there was no association identified between the development of
inhibitory antibodies and the von Willebrand factor content of products; switching
from a plasma-derived product to a recombinant product; or switching among
brands of factor VIII products. However, unexpectedly, there was a higher
likelihood of inhibitor development with second-generation full-length
recombinant products than with third-generation products.
The treatment of patients with inhibitors of FVIII is difficult. Assuming no
anamnestic response, low-titer inhibitors (ie, concentrations below 5 Bethesda
units [BU]) occasionally can be overcome with high doses of factor VIII. There is
no established treatment for bleeding episodes in patients with high-titer inhibitors.
A study of 26 patients over 2 years of age with severe hemophilia A tested the
prophylactic use of anti-inhibitor coagulant complex (AICC) for preventing
bleeding. Results show treatment 3 times per week on nonconsecutive days for 6
months led to a 62% reduction in all bleeding episodes as compared with on-
demand therapy. Other bleeding events including hemarthroses and target-joint
bleeding were also reduced; 61% and 72%, respectively.
Other approaches to treating patients with FVIII inhibitors include the following:
Porcine FVIII, which has low cross-reactivity with human factor VIII antibody
Activated prothrombin complex concentrate (PCC)
Activated FVII
Desensitization
Immune tolerance induction (ITI)
Recombinant activated FVIIa
Recombinant activated FVIIa (Eptacog Alfa or Novo Seven) has become the first
choice of bypassing agents. Recombinant FVIIa is a vitamin K–dependent
glycoprotein that is structurally similar to human plasma–derived FVIIa. It is
manufactured by using DNA biotechnology.
Intravenous recombinant FVIIa has been studied for treating bleeding episodes and
for providing hemostasis during surgery in patients with a particular bleeding
diathesis. Recombinant FVIIa is also effective and well tolerated in patients with
acquired hemophilia and in those with Glanzmann thrombasthenia.
To date, recombinant activated FVIIa has proven to be relatively free of the risk of
antigenicity, thrombogenicity, and viral transmission. However, the cost of this
product has precluded its use as prophylaxis in patients with inhibitors for FVIII;
when recombinant activated FVIIa has been used for this indication, select patients
have had severe complications related to bleeding.
In pediatric patients, off-label treatment with recombinant FVIIa significantly
reduced blood product administration, with 82% of patients subjectively classified
as responders. Clinical context and pH values before administration were
independently associated with response and 28-day mortality. Thromboembolic
adverse events were reported in 5.4% of patients.
Desensitization
Desensitization in nonemergency situations also may be feasible. This therapy
includes large doses of FVIII along with steroids or intravenous immunoglobulin
(IVIG) and cyclophosphamide. Success rates of 50-80% have been reported. In
life-threatening bleeding, methods to quickly remove the inhibiting antibody have
been tried. Examples include vigorous plasmapheresis in conjunction with
immunosuppression and infusion of FVIII with or without antifibrinolytic therapy.
Immune tolerance induction
In immune tolerance induction (ITI), a person is rendered tolerant to FVIII by
means of daily exposure to FVIII over several months to years. The overall
likelihood of success with ITI is 70% ± 10%.
First described by Backmann in 1977, ITI has been used with variations in the
dosing schedule for FVIII and with or without immunosuppressive therapy (eg,
cyclophosphamide, prednisone). Most of the recent protocols that use FVIII alone
have avoided use of immunosuppression because of the toxicity risk. This
technique is well established in acquired hemophilia but not in congenital
hemophilia.
Rituximab, a chimeric human-mouse monoclonal antibody against CD20, has been
used with success in ITI. Reports describe durable complete responses with a brief
courses of rituximab and prednisone with or without cyclophosphamide in patients
with autoimmune hemophilia and inhibitor titers of 5 to more than 200 BU.
Rituximab appears to be more effective in treating inhibitors in acquired
hemophilia than in hereditary hemophilia.
Attenuation of B-cells essential to the development of an acquired immune
response, or autoimmunization seen in patients with refractory FVIII inhibitors,
with a 4-week course of weekly rituximab has shown durable and complete
responses in several small trials. The addition of prednisone with or without
cyclophosphamide has increased response rates.
An international immune tolerance study was started in 2002 to compare the
efficiency, morbidity, and cost-effectiveness of low- versus high-dose ITI.
Prophylactic Factor Infusions
Most of the care for children with severe forms of hemophilia now takes place at
home, in the community, and at school, allowing children with hemophilia to
participate in normal activities that are otherwise impossible. This resulted from
the development of prophylactic regimens of factor concentrate infusions that are
administered at home, usually by a parent.
The main goal of prophylactic treatment is to prevent bleeding symptoms and
organ damage, in particular to joints. Hemophilia arthropathy that results from
recurrent or target joint bleeding can be prevented by this method.
Prophylaxis is not universally accepted, with only about half the children with
hemophilia A receiving this treatment modality in the United States. Reasons cited
for the lack of acceptance include need for venous access, factor availability,
repeated venipunctures, cost, and others. Research questions that remain
unanswered include when to initiate and stop infusions, dosing, and dose schedule.
Tools have now been developed to assess long-treatment effects.
Assessing adherence to prophylaxis
The Validated Hemophilia Regimen Treatment Adherence Scale–Prophylaxis
(VERITAS-Pro) prophylaxis is a patient/parent questionnaire that uses 6 subscales
(time, dose, plan, remember, skip, communicate), each containing 4 items, to
assess patient adherence to prophylactic hemophilia treatment. In a study of 67
patients with hemophilia, including 53 with severe FVIII deficiency, Duncan et al
found a strong correlation between VERITAS-Pro scores and adherence
assessments (eg, infusion log entries).
Pain Management
Pain management can be challenging in patients with severe hemophilia. Acute
bleeding in joints and soft tissues can be extremely painful. This requires
immediate analgesic relief.
Hemophilic chronic arthropathy is associated with pain. Narcotic agents have been
used, but frequent use of these drugs may result in addiction. Nonsteroidal anti-
inflammatory drugs may be used instead because their effects on platelet function
are reversible and because these drugs can be effective in managing acute and
chronic arthritic pain. Avoid aspirin because of its irreversible effect on platelet
function.
Other analgesics may include acetaminophen in combination with small amounts
of codeine or synthetic codeine analogs.
Complications
HIV-associated immune thrombocytic purpura is an exceedingly serious
complication in patients with hemophilia because it may result in lethal intracranial
bleeding. Correct platelet counts to less than 50,000/mL. Steroids are of limited
effectiveness, and intravenous immunoglobulin or anti-Rh(D) generally induces
transient remissions. Anti-HIV medications and splenectomies may result in long-
term improvement of thrombocytopenia.
Allergic reactions are occasionally reported with the use of cryoprecipitate, fresh-
frozen plasma (FFP), and factor concentrates. Premedication or adjustment of the
rate of infusion may resolve the problem.
Deterrence/Prevention
Do not circumcise male infants born to mothers who are known or thought to be
carriers of hemophilia until disease in the infant has been excluded with
appropriate laboratory testing. Perform blood assays of FVIII with cord blood.
When a cord blood sample is not available, obtain a sample from a superficial limb
vein; avoid femoral and jugular sites.
Routine immunizations that require injection (eg, diphtheria, tetanus toxoids, and
pertussis [DPT] or measles-mumps-rubella [MMR] vaccines) may be given by
means of a deep subcutaneous route (rather than deep intramuscular route) with a
fine-gauge needle.
Administer the hepatitis B vaccine (now routinely administered to all children)
soon after birth to all infants with hemophilia. Administer the hepatitis A vaccine
to those individuals with hemophilia and no hepatitis A virus antibody in their
serum.
In severe hemophilia, consider prophylactic or scheduled factor VIII. Prophylactic
replacement of FVIII is used to maintain a measurable level at all times, with the
goal of avoiding hemarthrosis and the vicious cycle of repetitive bleeding and
inflammation that results in destructive arthritis. This goal is achieved by
administering factor 2-3 times a week. The National Hemophilia Foundation has
recommended the administration of primary prophylaxis, beginning at the age of 1-
2 years.
Carrier testing
Carrier testing is valuable for women who are related to obligate carrier females or
males with hemophilia. Carrier testing may prevent births of individuals with
major hemophilia. This testing can be offered to women interested in childbearing
who have a family history of hemophilia. Prenatal diagnosis is important even if
termination of the pregnancy is not desired because a cesarean delivery may be
planned or replacement therapy can be scheduled for the perinatal period.
Phenotypic and genotypic (ie, restriction fragment–length polymorphism) methods
have advantages and disadvantages.
Preimplantation genetic diagnosis has been used as a possible alternative to
prenatal diagnosis in combination with in vitro fertilization to help patients avoid
having children with hemophilia or other serious inherited diseases.
The genetic
diagnosis is made by using single cells obtained during biopsy from embryos
before implantation. For this, fluorescence in situ hybridization is used. This
technique circumvents pregnancy termination.
Activity
Generally, individuals with severe hemophilia should avoid high-impact contact
sports and other activities with a significant risk of trauma. However, mounting
evidence suggests that appropriate physical activity improves overall conditioning,
reduces injury rate and severity, and improving psychosocial functioning.
Patients with severe hemophilia can bleed from any anatomic site after negligible
or minor trauma, or they may even bleed spontaneously. Any physical activity may
trigger bleeding in soft tissues. Prophylactic factor replacement early in life may
help prevent bleeding during activity, as well as helping to prevent chronic arthritic
and muscular damage and deformity.
Gene Therapy
With the cloning of FVIII and advances in molecular technologies, the possibility
of a cure for hemophilia with gene therapy was conceived. Substantial progress has
been made in the development of gene therapy for hemophilia A and hemophilia
B. This advancement reflects technical improvements of existing vector systems
and the development of new delivery methods.
Preclinical studies in mice and dogs with hemophilia have resulted in long-term
correction of the bleeding disorders and, in some cases, a permanent cure. The
induction of neutralizing antibodies often precludes stable phenotypic correction.
Certain promoters are prone to transcriptional inactivation in vivo, resulting in
failure of long-term FVIII expression. Several phase I trials of gene therapy are
ongoing in patients with severe hemophilia. Some individuals report fewer
bleeding episodes than before, and low levels of clotting factor activity are
occasionally detected.
Consultations
Consultations may be indicated with a hematologist, blood bank, pathologist, or
others as indicated by hemorrhagic complications. Early hematology consultation
for management of inhibitors is essential. Annual dental evaluation is
recommended.
A genetic counselor may be consulted. Genetic testing for hemophilia A is
available and must be offered to potential carriers. Prenatal testing is performed by
using amniocentesis or chorionic villus biopsy.
Before elective surgery is planned, a hematologist should be consulted to arrange
adequate coverage with antihemophilic factors and to arrange close follow-up to
ensure that factor levels are sufficient during the operation and in the recovery and
healing period.
Consult an orthopedic surgeon in cases of permanent joint deformities resulting
from recurrent hemarthrosis in relatively neglected cases or, occasionally, in cases
of repetitive bleeding in a single joint despite intensive prophylactic replacement of
factor and physiotherapy. Open surgical or arthroscopic synovectomy may
decrease bleeding and pain in the affected joint.
Management should be provided in coordination with a comprehensive hemophilia
care center.
KAWASAKI DISEASE
Etiology
Many factors point to an infective cause but no specific organism has been
found
Genetic susceptibility: highest in Asians irrespective of location and in
children and sibs of those with KD
KD-associated antigen in cytoplasmic inclusion bodies of ciliated bronchial
epithelial cells, consistent with viral protein aggregates; suggests respiratory
portal of entry
Seems to require an environmental trigger
Epidemiology
Asians and Pacific Islanders at highest risk
80% present at age <5 years (median is 2.5 years) but may occur in
adolescence
Poor outcome predictors with respect to coronary artery disease: very young
age, male, neutrophilia, decreased platelets, increased liver enzymes,
decreased albumin, hyponatremia, increased CRP, prolonged fever
Pathology
Medium size vasculitis, especially coronary arteries
Loss of structural integrity weakens the vessel wall and results in ectasia or
saccular or fusiform aneurysms; thrombi may decrease flow with time and
can become progressively fibrotic, leading to stenosis
Diagnosis
Absolute requirement: fever ≥5 days (≥101˚ F), unremitting and unresponsive;
would last 1−2 weeks without treatment plus any 4 of the following:
Eyes: bilateral bulbar conjunctivitis, non-exudative
Oral: diffuse oral and pharyngeal erythema, strawberry tongue, cracked
lips
Extremities: edema and erythema of palms and soles, hands and feet
acutely; subacute (may have periungual desquamation of fingers and toes
and may progress to entire hand)
Rash: polymorphic exanthema (maculopapular, erythema multiforme or
scarlatiniform with accentuation in the groin); perineal desquamation
common in acute phase
Cervical lymphadenopathy: usually unilateral and >1.5 cm,
nonsuppurative
Associated symptoms: GI (vomiting, diarrhea, pain); respiratory (interstitial
infiltrates, effusions); significant irritability (likely secondary to aseptic
meningitis); liver (mild hepatitis, hydrops of
gallbladder); GU (sterile pyuria, urethritis, meatitis); joints (arthralgias/arthritis—
small or large joints and may persist for several weeks)
Cardiac findings
Coronary aneurysms: up to 25% without treatment in week 2-3;
approximately 2−4% with early diagnosis and treatment; giant aneurysms
(>8 mm) pose greatest threat for rupture, thrombosis, stenosis and MI; best
detected by 2D echocardiogram
Myocarditis: in most in the acute phase; tachycardia out of proportion to the
fever and decreased LV systolic function; occasional cardiogenic shock;
pericarditis with small effusions. About 25% with mitral regurgitation, mild
and improves over time; best detected by 2D echocardiogram plus EKG
Other arteries may have aneurysms (local pulsating mass)
Clinical phases
Acute febrile: 1-2 weeks (or longer without treatment), diagnostic and
associated findings and lab abnormalities; WBC increased (granulocytes),
normocytic / normochromic anemia, normal platelets in first 1-2 weeks;
ESR and CRP must be increased (usually significantly for the ESR); sterile
pyuria, mild increase in liver enzymes and bilirubin; mild CNS pleocytosis.
Most important tests at admission are platelet count, ESR, EKG, and
baseline 2D-echocardiogram.
Subacute: next 2 weeks; acute symptoms resolving or resolved; extremity
desquamation, significant increase in platelet count beyond upper limits of
normal (rapid increase in weeks 2-3, often greater than a million); coronary
aneurysm, if present, this is the time of highest risk of sudden death. Follow
platelets, ESR and obtain 2nd echocardiogram.
Convalescent: next 2-4 weeks; when all clinical signs of disease have
disappeared and continues until ESR normalizes; follow platelet, ESR and
if no evidence of aneurysm, obtain 3
rd
echocardiogram; repeat echo and
lipids at 1 year. If abnormalities were seen with previous echo, more
frequent studies are needed, and cardiology follow-up and echocardiograms
are tailored to their individual status.
Treatment
Acute: (at admission): (a) IVIG over 10-12 hours (mechanism unknown but
results in rapid defervescence and resolution of clinical symptoms in 85-
90%); the IVIG gives the large drop in incidence of aneurysms. If continued
fever after 36 hours, then increased risk of aneurysm; give 2nd infusion. (b)
oral high dose aspirin (anti-inflammatory dosing) until afebrile 48 hours
o If winter, give heat-killed influenza vaccine if not yet received (Reye
syndrome); cannot give varicella vaccine acutely (live, attenuated
vaccine and concurrent IVIG would decrease its effectiveness, so
must delay any MMR and varicella vaccine until 11 months post-
IVIG.
Subacute (convalescent): change ASA to low dose (minimum dose for
antithrombotic effects as a single daily dose until ESR has normalized at 6-8
weeks and then discontinue if echocardiogram is normal; if abnormalities,
continue indefinitely
Complications and prognosis
Small solitary aneurysms: continue ASA indefinitely; giant or numerous
aneurysms need individualized therapy, including thrombolytic
Long-term follow-up with aneurysms: periodic echo and stress test and
perhaps angiography; if giant, catheter intervention and percutaneous
transluminal coronary artery ablation, direct atherectomy and stent
placement (and even bypass surgery)
Overall- 50% of aneurysms regress over 1-2 years but continue to have
vessel wall anomalies; giant aneurysms are unlikely to resolve
Vast majority have normal health
Acute KD recurs in 1-3%
Fatality rate <1%; all should maintain a heart-healthy diet with adequate
exercise, no tobacco and should have intermittent lipid checks.
LITERATURE:
1. USMLE STEP 2. Lecture notes 2019. Pediatrics. P. 458-467.
2.
www.kaptest.com/usmlebookresources
3. Nelson Textbook of Pediatrics, 21th Edition. - Expert Consult Premium
Edition - Enhanced Online Features and Print / by Robert M. Kliegman,
MD, Bonita M.D. Stanton, MD, Joseph St. Geme, Nina Schor, MD, PhD
and Richard E. Behrman, MD. - 2020. - 2680 p.
4. Manual of Pediatric Hematology and Oncology, Fifth Edition. Edited by:
Philip Lanzkowsky. Academic Press, 2016. - 1027p.
5. Hastings CA, Torkildson JC, Agrawal AK. Handbook of Pediatric
Hematology and Oncology: Children's Hospital and Research Center
Oakland, second edition. Oxford, John Wiley & Sons, 2012. – 378p.
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