Up-regulation of macrophage migration inhibitory factor in infants with acute neonatal necrotizing enterocolitis

AIMS

To investigate the role of macrophage migration inhibitory factor (MIF) and its downstream cytokine cascade in necrotizing enterocolitis (NEC).

METHODS AND RESULTS

The expression of MIF mRNA and protein in NEC guts was assayed by in situ hybridization and immunohistochemistry, respectively. Concentrations of MIF, interleukin (IL)-6 and IL-8 in the serum and in the supernatant of macrophage cultures were examined by ELISA. Increased expression of MIF mRNA and protein was observed in the NEC guts, mainly in the infiltrating macrophages in the mucosa and submucosal layers. Up-regulation of MIF was associated with the accumulation of macrophages and T cells. In addition, serum levels of MIF, IL-6 and IL-8 in NEC patients during the acute stage of the disease were significantly increased. The expression of MIF decreased both locally and systemically after the disease was resolved. MIF was also found to increase the secretion of IL-6 and IL-8 by macrophages isolated from healthy individuals in vitro in NEC.

CONCLUSIONS

MIF acts by stimulating macrophage production of IL-6 and IL-8. This further aggravates the inflammatory process by increasing the infiltration of neutrophils and activating inflammatory cells. The results of this study suggest that MIF plays an important role in the pathogenesis of NEC and may serve as a target for therapeutic intervention in NEC.

Growth in children with acute lymphocytic leukemia: a Pediatric Oncology Group study

We have studied 127 children from 5 participating institutions as to the effect of acute lymphoblastic leukemia (ALL) or the therapy used in the treatment of ALL on growth, growth hormone concentrations, and somatomedin activity. The study (SWOG No. 7581) was initiated in December 1975 and was closed to new entry in September 1979 and to data collection in February 1981. Heights, weights, and blood samples for growth hormone and somatomedin activity were obtained at the time of initial diagnosis and at intervals during the 55 months of observation. The percentage of boys less than 4 years of age below the 50th percentile is significantly greater than the expected 50% for both initial and final height (P less than 0.01). Girls less than 4 years appeared to have significantly different percentile height distribution from the normal for their final height measurement (P less than 0.05) but not for their initial height measurement. No other significant differences in the percentile height distribution were found. When growth rate, since time of diagnosis of ALL, is compared to the expected growth of normal children of the same age by linear regression analysis, there is a difference in the slope of the lines. Children with ALL are significantly shorter. The mean initial growth hormone and somatomedin concentration, 6.2 ng/ml and 1.3 micrograms/ml, respectively, vs mean remission growth hormone and somatomedin of 2.5 ng/ml and 1.1 micrograms/ml, respectively, were different. This was significant at P less than 0.01. The slope of the computed regression lines for multiple analysis of growth hormone and somatomedin were negative for more than 60% of the patients when compared to the initial concentration. These data suggest that a significant number of the children less than 4 years of age are short prior to the onset of therapy, and this persists throughout the course of their disease. Second, there is a reduction in growth rate during intensive therapy or the first year of the disease, with a normal growth rate thereafter. Third, growth hormone and somatomedin concentrations appear to be higher at the time of onset of the disease and decrease while on therapy.