Colony-stimulating factors and neutropenia: intersection of data and clinical relevance

Chronic disseminated candidiasis in patients with acute leukemia: emphasis on diagnostic definition and treatment

BACKGROUND

Chronic disseminated candidiasis (CDC) is a form of invasive fungal infection that occurs most commonly in patients with acute leukemia treated with chemotherapy. Recent studies have provided evidence for diagnostic alternatives to invasive procedures and more therapeutic options for the management of this complication. In order to put diagnostic criteria and methodological approach to the disease into the perspective of developing strategies for therapy, all relevant studies published in the English literature over the last 30 years were examined.

MATERIALS AND METHODS

The English-language articles located through MEDLINE (1966 to present) and from selected bibliographies.

RESULTS

There is increased recognition of CDC as complication of treatment with chemotherapy in patients with acute leukemia. Liver biopsy may not always be revealing or feasible to perform in some patients. Among the imaging modalities, magnetic resonance imaging has obtained preeminence as a non-invasive tool for the diagnosis of hepatosplenic fungal infections. Administration of amphotericin B (Amp B) in relatively large cumulative doses is needed to ensure appropriate control of the infection and prevention of future relapse. Patients intolerant of, or refractory to conventional Amp B have been successfully salvaged using fluconazole or lipid formulations of Amp B. A constellation of clinical, laboratory and radiologic parameters should be used to determine response and efficacy of therapy. There is sufficient evidence to support the safety and feasibility of continuing chemotherapy for acute leukemia in conjunction with antifungal treatment in patients diagnosed with CDC.

CONCLUSION

The development of CDC in patients with acute leukemia does not preclude further chemotherapy or constitute contraindication for bone marrow transplantation. Knowledge of the course and pattern of evolution of the disease and adopting aggressive therapeutic approach will likely reduce the morbidity and mortality from this complication.

Clinical role of GM-CSF in neutrophil recovery in relation to health care parameters

Recombinant growth factors, particularly granulocyte-macrophage colony-stimulating factor (GM-CSF), have been only available for a few years. Since their introduction they have affected the management of drug-induced neutropenia, the use of dose intensive chemotherapy regimens and in the setting of autologous stem cell transplantation. This review addresses the clinical role of GM-CSF, using the data available, in neutrophil recovery in relation to various health care parameters.

Early empiric antibiotic therapy for febrile neutropenia patients at low risk

Although it is apparent that certain patients with febrile neutropenic episodes can benefit from outpatient antibiotic therapy, not all low-risk patients are treated in this fashion. There are barriers, real and perceived, to implementing this approach for patients, health care providers, and caregivers. Table 3 summarizes the advantages and disadvantages of ambulatory management of febrile neutropenic patients. For many patients and physicians, outpatient oral antibiotics may be preferred, whereas for others a more conservative approach might be needed in order to feel comfortable with treating this population on an outpatient basis. In this situation, patients can be treated in a stepwise fashion as shown in Table 4. These alternatives allow physicians and patients options to discuss when planning treatment strategies for febrile neutropenia.

Targeting fungi: a challenge

Invasive fungal infections are more commonly identified in various categories of patients, mainly in cancer patients but also in those undergoing organ transplantation, patients in intensive care units, and those with AIDS. There is a great need to increase the awareness of practitioners who are still underestimating the morbidity and mortality relating to invasive fungal infections, and to stress the economic burden for the society and healthcare systems of invasive fungal infections. The list of fungal pathogens causing life-threatening complications has also increased recently, with the emergence of unusual fungi being more frequently identified in such settings. Early diagnosis of invasive fungal infections is still a major challenge for the clinician at the bedside. Identification of state-of-the-art management is also a difficult task for the clinical scientist involved in the assessment of optimal strategies to prevent and to treat those invasive fungal infections, although major progress has occurred in the last 5 years with the development of new, safe, and effective antifungal agents. Empiric therapy remains a very controversial issue that should be further investigated in high-quality clinical trials. Overall, clinical research in this difficult field requires independent and objective analysis; only large multicenter clinical trials can address these critical issues and rapidly provide convincing results leading to a better prognosis of patients with invasive fungal infections. These complications still represent too often an obstacle to successful control of severe underlying diseases. Clinical research on the appropriate ways to target fungi will not only define state-of-the-art management but also identify ineffective or redundant treatments. Such an approach will make a substantial contribution to the care of the high-risk patients within the next decade and will preserve our capacity for medical excellence.