Use of rHu GM-CSF in renal-transplant patients developing leukopenia

Drug-Induced Hematological Cytopenia in Kidney Transplantation and the Challenges It Poses for Kidney Transplant Physicians

Drug-induced hematological cytopenia is common in kidney transplantation. Various cytopenia including leucopenia (neutropenia), thrombocytopenia, and anemia can occur in kidney transplant recipients. Persistent severe leucopenia or neutropenia can lead to opportunistic infections of various etiologies. On the contrary, reducing or stopping immunosuppressive medications in these events can provoke a rejection. Transplant clinicians are often faced with the delicate dilemma of balancing cytopenia and rejection from adjustments of immunosuppressive regimen. Differentials of drug-induced cytopenia are wide. Identification of culprit medication and subsequent modification is also challenging. In this review, we will discuss individual drug implicated in causing cytopenia and correlate it with corresponding literature evidence.

Granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, and other immunomodulatory therapies for the treatment of infectious diseases in solid organ transplant recipients

PURPOSE OF REVIEW

Infections continue to cause significant morbidity and mortality in SOT recipients despite major advances in immunosuppressive and antimicrobial regimens. Immunomodulatory cytokines provide a potential means to augment the host immune response to infection. This review will focus on cytokine therapy for the prophylaxis and treatment of infections in solid organ transplant recipients, and will speculate on the potential for further advances in the field.

RECENT FINDINGS

In kidney and liver transplant recipients, granulocyte colony-stimulating factor (G-CSF) has been used successfully to reverse ganciclovir-induced neutropenia or cytomegalovirus-induced neutropenia. Although G-CSF also reversed corticosteroid-induced suppression of the neutrophil respiratory burst in vitro, prophylactic G-CSF failed to reduce infections or mortality in nonneutropenic solid organ transplant recipients. Published clinical experience with granulocyte-macrophage colony-stimulating factor (GM-CSF) in this population has been limited to case reports and a small case series, whereas the use of macrophage colony-stimulating factor (M-CSF) or interferon-gamma (IFN-gamma) has not been systematically investigated in controlled clinical trials.

SUMMARY

Despite encouraging results in vitro and in preclinical models, immunomodulatory cytokines have not met expectations when administered to SOT recipients. Nonetheless, the principle of selective enhancement of innate immunity for the prevention and treatment of infections in this patient population has promise and warrants further study.

The potential of GM-CSF to improve resistance against infections in organ transplantation

Immunosuppressed patients retain transplants but become more susceptible to opportunistic infections, which is a major complication in organ transplantation. Life-long immunosuppression for such patients could be reduced by creating immune tolerance, although this might be associated with an increased risk for infections and malignancies. An alternative therapeutic concept could consist of boosting the innate immune response against infections while continuing to suppress the adaptive immune response to prevent graft rejection. We propose granulocyte-macrophage colony-stimulating factor (GM-CSF) as a novel candidate to achieve this goal, based on recent studies in which beneficial effects were demonstrated in immunosuppressed mice with skin allografts and in dexamethasone-suppressed blood from healthy volunteers and blood from liver transplant recipients undergoing immunosuppressive therapy. Such data suggest that GM-CSF or other endogenous factors with similar properties should be examined in clinical trials.