Page 709 - Hematology_ Basic Principles and Practice ( PDFDrive )

Chapter 42 Sickle Cell Disease 601

The serum bilirubin level is higher in sickle cell anemia (Hb SS) Maternal complications include increased rates of painful episodes,
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than in Hb SC disease or sickle cell–β -thalassemia as a result of a severe anemia caused by iron or folate deficiencies, exaggeration of
greater hemolytic rate. The level rises after the first decade, possibly the physiologic “anemia of pregnancy,” increased infections (urinary
as a result of chronic hepatobiliary dysfunction. The aspartate ami- tract infections, pneumonias, endometritis), preeclampsia, and
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notransferase (AST) and alanine aminotransferase (ALT) levels are death. It is controversial whether the degree of anemia predicts the
often elevated, particularly in adult patients with sickle cell anemia, birth of babies with low birthweight. The occurrence of a perinatal
but mean levels are normal. Alkaline phosphatase levels are elevated death in a previous pregnancy and the presence of twins in the present
in all genotypes until puberty, which occurred later in males and in pregnancy are two major risk factors for an unfavorable outcome.
those with sickle cell anemia. Percutaneous liver biopsy is associated The course of pregnancy is more benign in Hb SC disease than in
with a high risk of severe complications and death in patients with sickle cell anemia.
SCD with acute hepatic syndromes. 197 Better fetal and maternal outcomes in recent years are largely
attributable to generally improved antenatal and obstetric care.
Cholelithiasis and Cholecystitis Patients should be followed in a high-risk obstetric clinic in addition
The prevalence of pigmented gallstones in SCD is directly related to to the hematology clinic and receive the usual vitamin, mineral,
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the rate of hemolysis. In sickle cell anemia, gallstones occur in and folate supplements. A high-calorie, high-protein diet can be
children as young as 3–4 years of age and are eventually found in considered. There is no specific therapeutic or preventive treatment
approximately 70% of patients. Some have recommended the surgi- for intrauterine growth retardation. Some experts recommend
cal removal of asymptomatic gallstones to avoid subsequent difficulty prophylactic transfusion, but a large controlled study showed no
in distinguishing gallbladder pain from acute painful episodes. This improvement in fetal outcome from this management option,
approach has become more feasible with the availability of laparo- although maternal symptoms are reduced. In addition to the usual
scopic cholecystectomy. 199 indications for transfusion therapy in SCD, transfusion therapy
is indicated for patients with cardiac or respiratory compromise,
Acute Hepatic Cell Crisis in preparation for cesarean section, preeclampsia, twin pregnancy,
Acute hepatic cell crisis presents with tender hepatomegaly, worsen- acute chest syndrome, Hb levels more than 20% below steady state
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ing jaundice, and fever. The likely etiology is hepatocellular cell or less than 5 g/dL, and previous history of perinatal mortality. If
ischemia. The AST and bilirubin are elevated, but rarely above the Hb is between 8 and 10 g/dL and transfusion is indicated for
300 IU/L and 255 µM, respectively. This syndrome usually resolves any of the reasons above, partial exchange should be performed
within 3–14 days with supportive care alone but can progress to liver (e.g., phlebotomy of 400–500 mL and transfusion of 2 units of
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failure and fatal outcome, therefore patients should be monitored packed RBCs). The type of delivery does not appear to represent a
closely and exchange transfusion initiated if they show signs of pro- problem, and both spontaneous delivery and cesarean section are well
gressive liver dysfunction (e.g., increasing AST). tolerated.
Some experts advise that hypertonic saline injections are contra-
Acute Hepatic Sequestration Crisis indicated for elective termination of pregnancy because of the risk of
Acute hepatic sequestration crisis presents with acute hepatic enlarge- sickling-induced vasoocclusion. However, most methods of abortion
ment and a dramatic fall in Hb concentration, the most likely are well tolerated. There are anecdotal reports of a higher incidence
mechanism being sequestration of sickled erythrocytes in the liver. of acute painful episodes after therapeutic abortion; inpatient intra-
Management is with supportive care and transfusions. venous hydration before and for the 24 hours after the procedure is
recommended.
Intrahepatic Cholestasis
Sickle cell intrahepatic cholestasis results in severe, asymptomatic Birth Control
hyperbilirubinemia without fever, pain, leukocytosis, hepatic failure, Modern nonestrogen-containing intrauterine devices should be
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or death. Asymptomatic hyperbilirubinemia without signs of considered. Although depot injections of medroxyprogesterone
progressive liver dysfunction (e.g., increasing AST) does not require (Depo-Provera) given every 3 months may be safe with regards to
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specific therapy. Evidence of progressive liver dysfunction should stroke risk, there is a risk of bone loss, a consideration in patients
prompt consideration of acute hepatic cell crisis and exchange with SCD and their propensity to skeletal complications. Oral con-
transfusion. traceptives containing low doses of estrogen can be considered with
no clear evidence of increased stroke demonstrated to date, although
Hepatitis C Infection the patients’ overall stroke risk should probably still be taken into
Chronic hepatitis C infection in SCD occurs with a prevalence that consideration until there is more phase IV follow-up on the clinical
is related to the number of transfusions received; it may be a leading experience. Another caution with low-dose estrogen oral contracep-
cause of cirrhosis. Liver transplantation has been used successfully as tion is the risk of contraceptive failure with less than excellent compli-
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therapy for this complication. If indicated, interferon-ribavirin can ance. There may be risks to contraception, but against this must be
be used to treat hepatitis C in patients with SCD. 202 weighed the risks of unintended pregnancy. Sexually active women
should have routine pelvic examinations and birth control
instructions.
Obstetric and Gynecologic Issues

Gynecologic complications (delayed menarche, dysmenorrhea, Renal Complications
ovarian cysts, pelvic infection, and fibrocystic disease of the breast)
are more common in women with SCD. Pregnancy entails increased Hypertension, proteinuria, hematuria, increasing anemia, and
risks to the mother and child compared with the general nephrotic syndrome reliably predict progression to renal failure,
population. which are clinical indices to pay attention to because the serum
creatinine may be misleading. Patients with sickle cell anemia exhibit
Pregnancy an increased proximal tubular secretion of creatinine. Thus patients
Pregnancy in patients with SCD is associated with increased risks to may have a significant decline in renal function before it is detectable
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both the mother and fetus, although these risks are not so great as to by measuring creatinine clearance. The mean age at presentation
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prohibit continuation of pregnancy. 203,204 The fetal complications of with end-stage renal disease is 41 years. Serum creatinine levels are
pregnancy, most of which are related to compromised placental blood low in all genotypes until age 18 years, when young men experience
flow, are the increased incidence of spontaneous early abortion, a rise, apparently related to increasing muscle mass. Creatinine levels
intrauterine growth retardation, low birthweight, and fetal death. increase with age in all genotypes, presumably because of declining