For those of us who have experienced low immunity after chemo or transplants, more indication of just how complex our bodies are, and how the neutrophil counts that we and our medical teams rely on, may not tell the full story. Quote:
… in healthy people, the fact that the effectiveness of neutrophils varies from one person to another usually has no significant consequences. In contrast, in patients with neutropenia, this individual variability can make a difference between life and death. This conclusion is drawn from the study based upon the blood analysis of four healthy volunteers. To use the model in the clinic, such analysis should be applied to large populations.
The model has already offered a plausible explanation for a number of medical mysteries. It helps explain, for example, why after chemotherapy, some cancer patients contract life-threatening infections even when in isolation under sterile conditions: If the neutrophils of these patients are “weak,” even the smallest numbers of bacteria, for example, those present in the gut, can tilt the fragile immune balance in favor of the bacteria.The study also explains why certain patients, following chemotherapy or a bone marrow transplant, may develop acute infections even if their neutrophil levels have returned to relatively normal levels. The chemotherapy lowers both neutrophil levels and function, making the tissues of these patients more penetrable to bacteria. The model suggests that as a result, in some patients the bacterial concentrations might increase so quickly that by the time the neutrophil counts rise back to “normal,” the rapidly multiplying bacteria have already gained a head start, so that the neutrophil recovery is insufficient for overcoming the infection. This scenario may eventually also shed light on the rare cases in which acute bacterial infections develop in individuals with normal immunological function. The model suggests that in such cases, a high growth rate of unusually virulent bacteria could overcome the appropriate quantitative and qualitative neutrophil response.