Morioka Y

Abnormal serum phenylalanine-tyrosine ratio and hyperferritinemia in malignant histiocytosis

Nine cases of childhood malignant histiocytosis (MH) showed an abnormally high serum phenylalanine (Phe)/tyrosine (Tyr) ratio (3.47 +/- 1.32) coincident with hyperferritinemia (50,800 +/- 33,600 ng/ml). Lactate dehydrogenase activity was also increased in these patients. These values were compared with data on sera from two groups of patients, acute leukemia cases (n = 14) and measles cases (n = 13), and with control values from normal healthy children (n = 38). The Phe/Tyr ratio was 1.57 +/- 0.54 for the acute leukemia (p less than 0.01) and 2.58 +/- 1.46 for the measles cases (NS), serum ferritin was 245 +/- 124 ng/ml for acute leukemia (p less than 0.01) and 167 +/- 117 ng/ml for measles (p less than 0.01). Accordingly, the concurrence of both abnormalities is considered to be characteristic for MH. It was also found that both serum Phe/Tyr ratio and ferritin levels reflect the disease activity, indicating that these two factors are useful prognostic indicators in the treatment of patients with MH.

Serum ferritin in stage IV neuroblastoma.

Serum ferritin is known to be one of the tumor markers for neuroblastoma. Serum ferritin is elevated in most children with neuroblastoma who are in stages III or IV, but it is not elevated in those in stage I or II. It has also been observed that iron load caused by blood transfusion shows a greater effect on serum ferritin levels than tumor activity due to neuroblastoma. Thus, serum ferritin increases in a linear fashion in children given repeated blood transfusions but the levels increase exponentially in children who have bulky neuroblastomas. Thus, serum ferritin values must be interpreted with caution in patients with advanced stages of neuroblastoma who inevitably require blood transfusions. The authors propose that the pretransfusion and posttransfusion serum ferritin values be in comparison with other tumor markers such as urinary VMA, urinary HVA, and neuron specific enolase. The serum ferritin level should not be used as a sole indicator of tumor activity in neuroblastoma.