Clinical characteristics of 13 solid organ transplant recipients with ganciclovir-resistant cytomegalovirus infection

Prospective comparison of valacyclovir and oral ganciclovir for prevention of cytomegalovirus disease in high-risk renal transplant recipients

AIMS

To compare the efficacy, costs and safety of oral ganciclovir and valacyclovir in the prophylaxis of cytomegalovirus (CMV) disease in renal transplant (RTx) recipients at high risk of CMV disease.

METHODS

A total of 83 patients were prospectively randomized to 3-month treatment with either oral ganciclovir (3 g/day) or oral valacyclovir (8 g/day). A 3rd group received no prophylaxis. Forty-nine patients were considered to be at high risk of CMV disease due to D+R- serologic status, OKT3/ATG treatment and/or acute rejection within 12 months after RTx. Twenty-three high-risk patients were treated with ganciclovir (GAN group), 17 patients with valacyclovir (VAL group), and 9 patients received no prophylaxis (C group).

RESULTS

No significant differences were found among the groups in their demographic characteristics, immunosuppressive protocols, D/R CMV serology, or CMV risk factors. The 12-month incidence of CMV disease was 89% in the C group compared with 9% in the GAN group and 6% in the VAL group (p < 0.001, GAN or VAL vs. C; p = 0.713, GAN vs. VAL). Treatment failure (death, graft loss, CMV disease or withdrawal from study) occurred in 17, 6, and 89% in the GAN, VAL, and C groups, respectively (p < 0.001, GAN or VAL vs. C; p = 0.285, GAN vs. VAL). The average CMV-associated costs per patient were EUR 3,161, 3,757, and 7,247 in the GAN, VAL, and C groups, respectively (p = 0.027).

CONCLUSION

Valacyclovir and oral ganciclovir are equally effective in the prophylaxis of CMV disease in high-risk RTx patients. Both regimens are cost-effective and help reduce CMV-associated costs by nearly 50% compared with patients without prophylaxis.

Epidemiology of cytomegalovirus disease in solid organ and hematopoietic stem cell transplant recipients

PURPOSE

The novel and traditional risk factors for cytomegalovirus (CMV) infection and disease in solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients, the current strategies for the prevention of CMV disease, the emerging syndrome of late-onset CMV disease, and the risk factors for antiviral drug resistance are described.

SUMMARY

The evolution of transplantation practices, the changes in the characteristics of donors and recipients, the introduction of novel immunosuppressive drugs, and the widespread use of antiviral drugs for CMV prevention have collectively influenced the natural history of CMV infection and disease in SOT and HSCT recipients. Strategies for CMV prevention with the use of antiviral drugs, whether as prophylaxis or as preemptive therapy, are effective in reducing the incidence of CMV disease in transplant recipients. However, late-onset CMV disease is now emerging as a serious problem. Donor and recipient CMV serostatus and other traditional risk factors for early-onset CMV disease appear to contribute to the occurrence of late-onset CMV disease during the first year after transplantation.

CONCLUSION

The epidemiology of CMV infection and disease has changed after transplantation. Strategies to prevent late-onset CMV disease include the prolonged use of antiviral prophylaxis, but this practice can lead to the emergence of antiviral drug resistance, which has been associated with high rates of morbidity and mortality.

Valacyclovir for Cytomegalovirus Prophylaxis Reduces the Risk of Acute Renal Allograft Rejection

BACKGROUND

Both oral ganciclovir and valacyclovir decrease the incidence of cytomegalovirus (CMV) disease after renal transplantation. Moreover, valacyclovir has been shown to reduce the risk of acute rejection. Our study was designed to compare the efficacy and safety of oral ganciclovir and valacyclovir in the prophylaxis of CMV disease after renal transplantation.

METHODS

A total of 83 patients were prospectively randomized to 3-month treatment with oral ganciclovir (3 g/day, n=36, GAN) or oral valacyclovir (8 g/day, n=35, VAL). A control group (DEF, n=12) was managed by deferred therapy.

RESULTS

No differences were found in demography, immunosuppression, or donor/recipient CMV serology. The 12-month incidence of CMV disease was 67% in the DEF group compared with 6% in the GAN group and 3% in the VAL group (P<0.001 GAN or VAL vs. DEF; P=0.575 GAN vs. VAL). The biopsy-confirmed acute rejection rate at 12 months was 12% in the VAL group compared with 34% in the GAN group (P=0.030) and 58% in the DEF group (P<0.001). The difference between the GAN and DEF groups was not significant (P=0.087). The average CMV-associated costs per patient were $3,072, $2,906, and $4,906 in the GAN, VAL, and DEF groups, respectively.

CONCLUSIONS

Valacyclovir and oral ganciclovir are equally effective in the prevention of CMV disease after renal transplantation. Both regimens are cost-effective. Valacyclovir is associated with a significantly reduced risk of acute rejection compared with both ganciclovir prophylaxis and deferred therapy.

Specific inhibition of human cytomegalovirus glycoprotein B-mediated fusion by a novel thiourea small molecule

A novel small molecule inhibitor of human cytomegalovirus (HCMV) was identified as the result of screening a chemical library by using a whole-virus infected-cell assay. Synthetic chemistry efforts yielded the analog designated CFI02, a compound whose potency had been increased about 100-fold over an initial inhibitor. The inhibitory concentration of CFI02 in various assays is in the low nanomolar range. CFI02 is a selective and potent inhibitor of HCMV; it has no activity against other CMVs, alphaherpesviruses, or unrelated viruses. Mechanism-of-action studies indicate that CFI02 acts very early in the replication cycle, inhibiting virion envelope fusion with the cell plasma membrane. Mutants resistant to CFI02 have mutations in the abundant virion envelope glycoprotein B that are sufficient to confer resistance. Taken together, the data suggest that CFI02 inhibits glycoprotein B-mediated HCMV virion fusion. Furthermore, CFI02 inhibits the cell-cell spread of HCMV. This is the first study of a potent and selective small molecule inhibitor of CMV fusion and cell-cell spread.

Respiratory virus infections in the immunocompromised host

The number of immunocompromised children in the population is increasing for a variety of reasons. Common respiratory viruses acquired in the community or in the hospital setting include the ortho- and paramyxoviruses and may cause severe lower respiratory tract disease in these children. Measles is again becoming a threat. Particularly in transplant patients, Herpes group viruses and adenoviruses, often part of a reactivation illness, can cause potentially life-threatening disease. The use of rapid molecular diagnostic techniques and an increasing array of antiviral therapies can help ensure a good outcome in many cases, although controlled clinical trial data are often lacking. Immunotherapeutic strategies using specific antibodies or cytotoxic T cells are being developed and are likely to have an increasing role in prophylaxis and pre-emptive therapy in the future. The development and introduction of vaccines against common respiratory diseases will help reduce the risks faced by these susceptible children.