Comparison of Quantitative PCR and Antigenemia in Cytomegalovirus Infection in Renal Transplant Recipients

Cytomegalovirus infection is a common complication of renal transplantation. Antigen pp65 levels serve as indicators of viral load, although the technique is difficult to perform and interpret. We sought to determine whether quantitative PCR had a higher sensitivity and predictive value in CMV infection.

METHODS

The study included 100 renal transplant recipients who were screened for IgM and IgG at the time of admission. On days 7, 15, 30, 45, 60, 75, 90, 120, 180, and 360, antigenemia tests were performed on blood (pp65) and urine, and a quantitative PCR on blood. Among 59 patients recruited between November 2003 and August 2004 the mean age was 54.5 +/- 12.9 years. Two patients did not reach 90 days follow-up (3%); four patients have not surpassed 90 days (7%); 22, 120 days (37%); and 31, 180 days (53%). Ninety-three percent of patients showed anti-IgG CMV-positive titers with all being IgM CMV-negative at baseline. The patients at risk for infection were given valgancyclovir as prophylaxis throughout the study.

RESULTS

At 474 visits, 8 samples (2.4%) were positive with urine; 5 (1.4%) with pp65, and 15 (4.7%) with PCR. Among the 15 positive samples, two (>100,000 and 3250 copies) revealed agreement of positive IgM and shellvial test on urine; two (15,100 and 5670 copies), antigen pp65 1+; one (17,400 copies) with pp65 2+ and shellvial urine; two (99,400 and 28,300 copies) with pp65 1+ and shellvial urine; and eight remaining determinations, 749, 2250, 686, 928, 2250, 26600, 777, and 2790 copies. The rest of the tests were negative.

CONCLUSION

The preliminary results of this study demonstrated that quantitative PCR was a useful rapid tool for diagnosing and monitoring CMV infections.

[Cytomegalovirus viral load and antigenemia in the monitorization of prophylactic treatment with valganciclovir in renal transplant recipients]

Cytomegalovirus (CMV) disease is one of the most relevant infectious complications in solid organ transplant, and we must perform an appropriate prophylactic intervention. The goal of this study was to evaluate the effectiveness of prophylactic treatment with valganciclovir in renal transplant recipients in the first three months post transplantation by shell vial urine culture assay, and by measuring antigenemia (pp65) and CMV viral load, the latter by PCR. The population of the study included 100 renal transplant recipients. We analyzed the results of 36 patients recruited between November 2003 and July 2004 who were receiving a prophylactic oral treatment with valganciclovir, and who had finished the follow-up period of 90 days. The three tests mentioned above were performed on days 7, 15, 30, 45, 60, 75 and 90. No positive antigenemia was detected, the virus was cultured in a urine specimen and, in one patient, three measurements of viral load in serum were positive. Preliminary results of the study suggest that universal chemoprophylaxis with valganciclovir is effective for the prevention of CMV infection in renal transplant recipients and that, although all three tests used were useful, the measurement of CMV viral load seems to be the most appropriate method for monitoring these patients.

[The importance of hydrostatic valves in the treatment of adult chronic hydrocephalus]

BACKGROUND AND OBJECTIVE

Earlier designs of hydrocephalus valves, focusing on a reduction of the problem of overdrainage, were proved to be insufficiently. Since the middle of the 90's hydrostatic valve, constructions are available, which should solve this problem. The objective of the study was to evaluate, whether these gravitational shunts would indeed reduce the percentage of overdrainage in shunted patients.

METHODS

In 51 patients clinical evaluation and MRI was performed pre- and in regular intervals postoperatively. 21 received a Dual-Switch valve, 14 a programmable Codman Hakim plus Shuntassistent and 6 a combination of a conventional valve with Shuntassistent.

RESULTS

Over 90% of the patients had clear and persisting (over 24 months) clinical benefit from shunting. Only one suffered for some days after shunt implantation from headache in the upright position. No other clinical or imaging hints were given on an overdrainage. The ventricular size was unchanged in patients with a normal pressure hydrocephalus after shunting. In patients with occlusive hydrocephalus only a few showed a significant reduction of the ventricular wide.

CONCLUSION

Gravitational shunts seem to decrease the overdrainage linked to the treatment of chronic hydrocephalus in shunted patients, therefore its use should be standardised when treatment chronic hydrocephalus.

[Significance of hydrostatic valves in therapy of chronic hydrocephalus]

Earlier design changes in hydrocephalus valves focusing on reducing overdrainage failed. Since the middle of the 1990s, hydrostatic valve constructions have been available which are claimed to solve this problem. The objective of this study was to evaluate the efficiency of these constructions. Clinical status and ventricular size were evaluated in 45 patients with chronic hydrocephalus before and 1, 6, and 26 weeks after operation. In 35 of these, a Miethke dual-switch valve was implanted (treatment group 1), and the others received a combination of a programmable Codman-Hakim valve and a Miethke shunt assistant as the hydrostatic element of the configuration (treatment group 2). A third group (n = 6) had already been shunted but suffered from overdrainage symptoms which could not be overcome by conservative measures. In these cases, the only operative treatment was the implantation of a Miethke shunt assistant adjunctively to the existing valve. In groups 1 and 2, there was a significant permanent improvement in the clinical state in nearly 80% of cases and a moderate permanent improvement in about 10%. Mild clinical and radiological signs of overdrainage occurred in three patients during the first postoperative week but resolved without further operative measures within the next 5 weeks. Typically, the ventricular width was not or only marginally reduced in these 45 patients. In the patients treated for symptoms of overdrainage (group 3), complaints resolved within the first week after implantation of the shunt assistant. The study indicates that gravitational shunts may be very effective in preventing overdrainage in chronic hydrocephalus, and therefore these constructions could represent the gold standard in the treatment of chronic hydrocephalus.