Neutrophil infiltration into human gliomas

Human gliomas were analysed for the infiltration of neutrophils using immun ohistochemistry by staining sections for CD15-positive and myeloperoxidase- positive cells. Over 70% of all glioma samples analysed (n = 105) had signi ficant neutrophil infiltration, but there was a marked and significant corr elation between tumour grade and the extent of the neutrophil infiltration. In the low grade tumours only 40-50% had significant infiltration while in glioblastoma multiforme over 85% of the samples analysed had significant i nfiltration. Numbers of neutrophils infiltrating glioblastoma multiforme tu mours were also greater than in the other tumour groups. Circulating white blood cell counts were elevated above the normal range in all glioma patien ts, but this elevation was entirely due to increased numbers of circulating neutrophils. Again, the highest numbers of circulating neutrophils were se en in the glioblastoma multiforme patients. These experiments indicate that glioma-derived factors may directly or indirectly affect the number of cir culating neutrophils and influence their infiltration into the tumours.