Detection of recurrent cytomegalovirus infection in renal-transplant patients

CMV-specific IgA appeared in the sera of 14 (93%) of 15 renal-transplant patients between one and 12 weeks after transplantation and remained detectable for as long as the patients were followed up (range, eight to 66 weeks). Only six (40%) of the 15 developed CMV-specific IgM (a result which is in agreement with other studies [3]), developing it between eight and 12 weeks after transplantation; in each case, the IgM was detected for as long as the patient was followed up. The one patient (patient 15) who did not develop CMV-specific IgA was one of those who did develop CMV-specific IgM. CMV was isolated from the urine of 11 (73%) of the 15 patients as early as 3.5 weeks after transplantation and as late as 32 weeks after transplantation (patient 14). Increases in the titer of CMV-specific IgG occurred between five weeks and 14 months after transplantation; in 13 of the 15 patients, this increase occurred later than that of CMV-specific IgA (or of CMV-specific IgM in the case of patient 15); in one case (patient 12) it occurred earlier than CMV-specific IgA, and in one case (patient 14), it appeared concurrently with CMV-specific IgA. Therefore, in six (40%) of 15 cases, CMV-infection was detected earliest by the appearance of CMV-specific IgA; in four (27%) of the cases, CMV-specific IgA appeared concomitantly with isolation of CMV-specific IgM or CMV, and in the remaining five (33%) of the cases, isolation of CMV was the first indication of recurrent CMV infection.