Severity of iron overload in patients with sickle cell disease receiving chronic red blood cell transfusion therapy

Chronic transfusion therapy is being used more frequently to prevent and treat the complications of sickle cell disease. Previous studies have shown that the iron overload that results from such therapy in other patient populations is associated with significant morbidity and mortality. In this study we examined the extent of iron overload as well as the presence of liver injury and the predictive value of ferritin in estimating iron overload in children with sickle cell disease who receive chronic red blood cell transfusions. A poor correlation was observed between serum ferritin and the quantitative iron on liver biopsy (mean 13.68 +/- 6.64 mg/g dry weight; R = 0.350, P =.142). Quantitative iron was highly correlated with the months of transfusion (R = 0.795, P <.001), but serum ferritin at biopsy did not correlate with months of transfusion (R = 0.308, P =.200). Sixteen patients had abnormal biopsies showing mild to moderate changes on evaluation of inflammation or fibrosis. Liver iron was correlated with fibrosis score (R = 0.50, P =.042). No complications were associated with the liver biopsy. Our data suggest that, in patients with sickle cell disease, ferritin is a poor marker for accurately assessing iron overload and should not be used to direct long-term chelation therapy. Despite high levels of liver iron, the associated liver injury was not severe.

Tonsillectomy, adenoidectomy, and myringotomy in sickle cell disease: perioperative morbidity. Preoperative Transfusion in Sickle Cell Disease Study Group

PURPOSE

To compare the rates of perioperative morbidity of patients with sickle cell anemia who were randomly assigned to 2 preoperative transfusion regimens and to identify predisposing factors for perioperative complications.

PATIENTS AND METHODS

Investigators at 36 centers enrolled 118 patients who were scheduled to have elective surgery and agreed to randomization between 2 preoperative transfusion regimens. Forty-seven subjects were enrolled but not randomized, including 20 who were not transfused before surgery. Perioperative management was based on a prescribed care plan.

RESULTS

Tonsillectomy and/or adenoidectomy (TA) were performed on 136 persons, and 29 had myringotomy as their primary procedure. There were no differences in the frequency of complications between the randomized groups. The serious, non-transfusion complication rates for randomized patients were 32% (34 of 107) for TA and 36% (4 of 11) for myringotomy. A history of pulmonary disease was a predictor of postoperative sickle cell-related events for patients undergoing TA surgery.

CONCLUSIONS

The more intensive transfusion regimen did not result in fewer perioperative complications. The high frequency of complications emphasizes the need for anticipatory management of persons undergoing TA. A history of pulmonary disease identifies patients at increased risk for sickle cell-related events after TA surgery. Patients undergoing myringotomy have a low frequency of sickle cell-related events but a significant frequency of other serious perioperative complications.

Surgery in patients with hemoglobin SC disease. Preoperative Transfusion in Sickle Cell Disease Study Group

While surgery is commonly required for complications related to hemoglobin SC (HbSC) disease, little is known about the perioperative complications or the indications for preoperative transfusion in this group. We describe the patient characteristics, preoperative transfusion regimens, and outcome in 92 patients with HbSC and sickle-variants undergoing elective surgery. Thirty-eight percent of the patients were transfused preoperatively. Patients transfused were more likely to have been hospitalized in the year prior to the surgery and scheduled for abdominal procedures. Abdominal and ear, nose and throat procedures were the most common surgeries in our study. The overall complication rate was 18% and sickle cell-related complications occurred in 9% of patients. In patients undergoing intra-abdominal procedures, the incidence of sickle cell-related complications was significantly higher in those patients not transfused prior to their surgery (35 vs. 0%). There were two deaths. We recommend selective use of preoperative transfusion in patients with HbSC disease undergoing surgery. Transfusion appears to be beneficial in abdominal cases but is not necessary with minor procedures such as myringtomy.

A comparison of conservative and aggressive transfusion regimens in the perioperative management of sickle cell disease. The Preoperative Transfusion in Sickle Cell Disease Study Group

BACKGROUND

Preoperative transfusions are frequently given to prevent perioperative morbidity in patients with sickle cell anemia. There is no consensus, however, on the best regimen of transfusions for this purpose.

METHODS

We conducted a multicenter study to compare the rates of perioperative complications among patients randomly assigned to receive either an aggressive transfusion regimen designed to decrease the hemoglobin S level to less than 30 percent (group 1) or a conservative regimen designed to increase the hemoglobin level to 10 g per deciliter (group 2).

RESULTS

Patients undergoing a total of 604 operations were randomly assigned to group 1 or group 2. The severity of the disease, compliance with the protocol, and the types of operations were similar in the two groups. The preoperative hemoglobin level was 11 g per deciliter in group 1 and 10.6 g per deciliter in group 2. The preoperative value for hemoglobin S was 31 percent in group 1 and 59 percent in group 2. The most frequent operations were cholecystectomies (232), head and neck surgery (156), and orthopedic surgery (72). With the exception of transfusion-related complications, which occurred in 14 percent of the operations in group 1 and in 7 percent of those in group 2, the frequency of serious complications was similar in the two groups (31 percent in group 1 and 35 percent in group 2). The acute chest syndrome developed in 10 percent of both groups and resulted in two deaths in group 1. A history of pulmonary disease and a higher risk associated with surgery were significant predictors of the acute chest syndrome.

CONCLUSIONS

A conservative transfusion regimen was as effective as an aggressive regimen in preventing perioperative complications in patients with sickle cell anemia, and the conservative approach resulted in only half as many transfusion-associated complications.

Production of enterotoxin A and thermonuclease by Staphylococcus aureus in legumes

Growth, enterotoxin A (SEA) and thermonuclease (TNase) production of S. aureus (Strains CP 7 and FRI 722) was determined in media produced from the following heat or irradiation sterilized legumes: peas, black beans, mung beans, adzuki beans and soybeans. Media containing the five legumes alone or in combination with Brain Heart Infusion Broth (BHI) were tested. With the exception of heat-sterilized black beans and adzuki beans, S. aureus growth was excellent in all media with cell counts after 48 h (25 degrees C) exceeding 10(8) cfu/ml. In black beans and adzuki beans cell counts were 1-2 log-cycles lower. Enterotoxin A was produced in amounts of 33 to 72 ng/ml in BHI after 48 h. Almost no toxin was produced in the four different beans following heat or irradiation treatment; in peas the toxin concentration reached 14 to 15 ng/ml. In the medium prepared from irradiated soybeans and BHI the final toxin concentration was about the same as in BHI alone. In all the other media consisting of a combination of legumes with BHI toxin concentrations were three to four times higher than in BHI alone. Production of thermonuclease showed variation and did not always correlate with enterotoxin production.