Autosomal dominant progressive external ophthalmoplegia (adPEO) is a mitochondrial disease characterized by accumulation of multiple large deletions of mtDNA in patients' tissues. We previously showed that the disease is genetically heterogeneous by assigning two nuclear loci predisposing to mtDNA deletions: one on chromosome 10q 23.3-24.3 in a Finnish family and one on 3p 14.1-21.2 in three Italian families. To reveal any locus-specific disease features, we report here the clinical, biochemical, and molecular genetic characteristics of the 10q-linked disease in the single family reported to date. All seven patients and four asymptomatic subjects had ragged-red fibers and multiple deletions of mtDNA in their muscle. Ptosis and external ophthalmoplegia were the major clinical findings, and depression or avoidant personality traits were frequently, but not consistently, present in the subjects carrying mutant mtDNA. In six of the subjects with mutant mtDNA, the activities of the respiratory chain complexes I or IV, or both, were below or within the low normal range. Two autopsy studies revealed the characteristic distribution of mutant mtDNA in these patients: highest proportion of mutant mtDNA is found in different parts of the brain, followed by the skeletal and ocular muscle, and the heart.

Respiratory viruses are found commonly during febrile episodes in children with leukemia. The detection of viruses permits the use of available antiviral agents, may explain a poor response to antimicrobial agents, and minimizes the proportion of febrile episodes without possible etiologic agents in children with leukemia.

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Recovery of humoral immunity after cessation of chemotherapy for childhood acute lymphoblastic leukemia (ALL) was investigated by determining blood leukocyte, lymphocyte and B‐lymphocyte, and serum immunoglobulin (Ig) levels and IgG subclasses at 0, 1, 3, 6, 9, and 12 months after cessation of chemotherapy for ALL in 14 patients. Blood B‐lymphocytes were analyzed with the use of flow cytometry and monoclonal CD20 antibody. At cessation of chemotherapy, the amount of blood B‐lymphocytes was subnormal in most patients but increased to normal levels in 1 month after therapy was discontinued. The recovery of serum Ig, which reflect B‐cell function, was slower, but occurred by 6 months after therapy was discontinued in most patients. The authors conclude that by 6 months after cessation of chemotherapy for ALL, a sufficiently functioning immune system by these parameters is established and that prophylactic antibiotics can be withdrawn and immunizations started. Cancer 1992; 69:1481‐1486.

The pharmacokinetics of MTX and 6MP may have significant influence on the risk of relapse. The value of dose adjustments by E-MTX and E-6TGN remains to be determined.