Tehran University Medical Journal

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Background: Hyperuricemia is one of the oncologic emergency that occurs most often in patients with hematologic disorders particularly leukemia and high-grade lymphoma. This study was conducted in order to determine the prevalence of hyperuricemia with respect to prophylactic treatment (in particular allopurinol) in patients with lymphoproliferative disease in the pediatric hematologic ward of Imam Khomeini Hospital, Tehran.
Methods: In this retrospective cross-sectional study, 316 children (75 females, 241 males) under the age of 12 years participated. Among the subjects, 66 patients (20.9%) had lymphoma and 250 patients (79.1%) had leukemia.
Results: Of the 56 (17.7%) patients diagnosed with hyperuricemia, 13 with lymphoma (19.7%) and 43 (17.2%) with acute lymphoblastic leukemia, 52 patients showed hyperuricemia after induction of chemotherapy (p<0.001). Hyperuricemia was more prevalent in patients with more advanced disease (50.9% in stage IV, p<0.001). Hyperuricemia was more frequent in male patients (p<0.001). Among the 217 patients who had received prophylaxis (hydration, alkalization, allopurinol), 19 (8.7%) subjects had hyperuricemia compare to 37.3% in the group of patients who did not receive prophylactic treatment (p<0.001).
Conclusion: From the literature reviewed, a recombinant form of the urate oxidase enzyme (rasburicase) is a safe and effective alternative to allopurinol to rapidly control plasma uric acid concentrations in patients with hematologic malignancy at high risk for tumor lysis during induction of chemotherapy. In this respect, we recommend a prospective study to compare allopurinol and rasburicase in children with leukemia and lymphoma.

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Background: Fanconi anemia (FA) is a rare autosomal recessive disorder characterized by short stature, skeletal anomalies, increased incidence of solid tumors and leukemia, and bone marrow failure (aplastic anemia). FA has been reported in all races and ethnic groups and affects men and women in an equal proportion. The frequency of FA has been estimated at approximately 1 per 360,000 live births. In some populations, including Ashkenazi Jews, Turks, Saudi Arabians and Iranians, this frequency appears to be higher, probably as a result of the founder effect and consanguineous marriage. Because of extensive genetic and clinical heterogeneity (the age of onset, clinical manifestations and survival), diagnosis of FA on the basis of clinical data alone is unreliable and its molecular diagnosis is difficult. The diagnosis of FA exploits the hypersensitivity of FA lymphocytes and fibroblasts to bifunctional alkylating agents such as mitomycin C (MMC), diepoxybutane (DEB) and nitrogen mustard and differentiates it from idiopathic aplastic anemia. In this study, in addition to the patients' clinical profiles, a cytogenetic test using MMC was implemented for an accurate diagnosis of Fanconi anemia.

Methods: In this study, the lymphocytes of 20 patients referred for FA, and those of their normal sex-matched controls, were treated with three different concentrations of mitomycin C (20, 30, 40 ng/ml). Slides were prepared and solid stained. In order to determine the number and kind of chromosome abnormalities, 50 metaphase spreads from each culture were analyzed. Clinical information was obtained from patient files.

Results: Five patients manifested increased chromosome breakage with MMC, confirming the FA diagnosis. Two different concentrations of MMC (30, 40 ng/ml) were most effective.

Conclusion: The chromosomal breakage test is important for the accurate diagnosis of Fanconi anemia. DNA crosslinking agents used to treat idiopathic aplastic anemia may be lethal for patients with FA. Thus, aplastic anemia patients with unknown etiology, infants with congenital abnormalities involved in FA and siblings of FA patients should also be cytogenetically tested.

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Background: Kawasaki disease (KD) is an acute vasculitis in children. Eosinophilia, a reflection of the host's immune response that can cause tissue damage, has been associated with KD, with eosinophils preferentially accumulating in the microvasculature. In early-stage Kawasaki disease (KD), lesions (perivasculitis and vasculitis) first form in the microvessels, which can then extend to the larger vessels and result in coronary artery aneurysms, possibly leading to myocardial infarction even in young children. Overall, the prevalence of coronary artery aneurysms in children with Kawasaki disease is about 10-18%, which is much higher among those not treated early in the course of the illness.  We performed this study to gain a better understanding of the initial pathogenesis of KD and to assess the relationship between eosinophilia and coronary artery disease.

Methods:  The data from forty-eight patients at Vali-asr Hospital of the Tehran University of Medical Sciences (1996-2006) were included in this cross-sectional descriptive analysis. The presence and degree of coronary artery disease was assessed by echocardiography. Data was analyzed via Fisher's exact test and student's t-test using SPSS software, v. 11.5.

Results: Eosinophilia was seen in 10 cases (22%) and cardiac lesions were observed in 19 cases (41%). The frequency of microvessel lesions was significantly lower in patients with eosinophilia (10% with eosinophilia versus 50% without eosinophilia, p<0.03). The frequency of microvessel lesions was lower in males than in females (35 vs. 44%, respectively), although this was not significant. We found no correlation between the frequency of microvessel lesions and age.

Conclusions: In spite of the controversies regarding eosinophilia and microvessel lesions, in this study the number of circulating eosinophils was associated with fewer cardiac lesions. Comparative studies are needed to determine the exact relationship.

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Background: Hyperuricemia is one of the oncologic emergency that occurs most often in patients with hematologic disorders particularly leukemia and high-grade lymphoma. This study was conducted in order to determine the prevalence of hyperuricemia with respect to prophylactic treatment (in particular allopurinol) in patients with lymphoproliferative disease in the pediatric hematologic ward of Imam Khomeini Hospital, Tehran. Methods: In this retrospective cross-sectional study, 316 children (75 females, 241 males) under the age of 12 years participated. Among the subjects, 66 patients (20.9%) had lymphoma and 250 patients (79.1%) had leukemia. Results: Of the 56 (17.7%) patients diagnosed with hyperuricemia, 13 with lymphoma (19.7%) and 43 (17.2%) with acute lymphoblastic leukemia, 52 patients showed hyperuricemia after induction of chemotherapy (p<0.001). Hyperuricemia was more prevalent in patients with more advanced disease (50.9% in stage IV, p<0.001). Hyperuricemia was more frequent in male patients (p<0.001). Among the 217 patients who had received prophylaxis (hydration, alkalization, allopurinol), 19 (8.7%) subjects had hyperuricemia compare to 37.3% in the group of patients who did not receive prophylactic treatment (p<0.001). Conclusion: From the literature reviewed, a recombinant form of the urate oxidase enzyme (rasburicase) is a safe and effective alternative to allopurinol to rapidly control plasma uric acid concentrations in patients with hematologic malignancy at high risk for tumor lysis during induction of chemotherapy. In this respect, we recommend a prospective study to compare allopurinol and rasburicase in children with leukemia and lymphoma.