Iron overload due to blood transfusions in sickle cell disease

Author: V. Dimov, M.D.

A 29 year old AAM with a known history of sickle cell disease and multiple blood transfusions was admitted through the ER with symptoms consistent with his prior sickle cell crises. He complained of pain in his knees, hips, and back that had been "off and on" for the last couple of months. It became markedly worse this afternoon and began to involve his chest and his arms. He denies fevers, chills, rigors, or night sweats.

PMH
Sickle cell disease, aseptic necrosis of bone (hips and back)

Medications
Hydroxyurea, gabapentin, methadone, deferasirox, folic acid, MVT

FMH
Mother: Genetic (sickle cell trait)
Father: Genetic (sickle cell trait)
Brother: Genetic (sicke cell trait)

Physical examination
VSS
Eyes: anicteric
ENT: Oropharynx clear, no plaques or exudates.
Respiratory: clear to auscultation bilaterally, no respiratory distress, no rales, no rhonchi, no wheezing.
Cardiovascular: no murmurs, no rubs, no gallops, regular rate and rhythm.
Gastrointestinal: soft, nontender, nondistended.
Genitourinary: no CVA tenderness
Extremities: no c/c/e

What is the most likely diagnosis?
Sickle cell crisis

What tests would you order?
CBC
Reticulocyte count
CMP
CXR
UA

What happened?
CBC showed anemia with evidence of iron overload from previous ferritin measurements.


Figure 1. CBC in sickle cell anemia.


Figure 2. Increase in ferritin level secondary to blood transfusions in a 29-year-old patient with sickle cell disease.

Sickle cell crisis resolved with pain medications, NS at 100 cc/hr and O2 via NC. The patient received 2 U PRBC. CXR was negative for acute chest syndrome and UA was negative for infection.

Deferasirox (Exjade), an oral iron chelator, was continued.

Final diagnosis
Chronic iron overload due to blood transfusions in sickle cell disease

Summary
There is no specific hemoglobin number which triggers blood transfusion. Iron overload is a significant problem for patients with sickle cell disease who commonly have a ferritin level of 3,000. Many patients are able to tolerate a hemoglobin level in 6-7 mg/dL range without adverse symptoms.

Audio
Audio lecture: Sickle Cell Disease. Dr. Raymond Osarogiagbo. Podcasting Project for the UT Internal Medicine Residency Program, 12/2007.
Sickle cell drug hydroxyurea underused, experts agree. Reuters, 02/2008.

Created: 09/13/2007
Updated: 02/01/2008