Fever and Petechiae in an Infant

James Harper, MD

Department of Pediatrics, University of Nebraska Medical Center, Omaha, NE

This case was reviewed and updated in May 2011 by members of the Teaching Cases Subcommittee

Copyright of the American Society of Hematology, 2006. ISSN: 1931-6860.


The patient was started on combination chemotherapy consisting of Prednisone, Vincristine, and L-asparaginase (induction phase). At day 14 of induction, he had no detectable leukemia cells on either the bone marrow aspirate or on flow cytometry. He completed induction at day 28.

At the end of the first month of therapy, he entered a clinical remission. Remission at this point refers to a condition in which a patient likely still has a substantial number of leukemia cells, but they can no longer be found by conventional techniques; the patient has recovered normal marrow function; and he has no systemic symptoms. If treatment were to end at this point, he would most likely relapse rapidly.

Consider that a typical patient with ALL may have 100 billion lymphoblasts at diagnosis, and that induction chemotherapy can kill 99% of them. The patient would still be left with a billion lymphoblasts. Some of these are in permanent G0 state; that is, they are not dividing, and they cannot re-enter the cell cycle. Most, though, are still capable of replication.

Later phases of therapy are in place to slowly carve the number of lymphoblasts down and to consolidate the patient’s remission.

The speed of entry into remission is prognostically significant for ALL. Patients who are not in remission by the 28th day of induction chemotherapy may let go into remission, but face a much lower likelihood of remaining in remission. Those patients who have emptied their marrow of lymphoblasts and who show signs of marrow recovery by day 15 of induction do better than those who do not.

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