Prospective evaluation of BK virus DNAemia in renal transplant patients and their transplant outcome

BACKGROUND

After renal transplantation, the prevalence of BK virus (BKV) viruria, viremia, and nephritis (BKVAN) has been estimated at 30%, 13%, and 8%, respectively.

PATIENTS AND METHODS

The aim of this prospective study was to assess the occurrence of BKV DNAemia during the first year after renal transplantation and to determine the prevalence of BKVAN, in the absence of immunosuppression alteration, following positive BKV DNA. BKV DNAemia was assessed systematically in 104 renal transplant patients on postoperative days 60, 90, 135, 180, 270, and 360.

RESULTS

Of the 104 patients, 7 (6.7%) presented with at least 1 episode of BKV DNAemia. Those with positive BKV DNAemia had a cumulative steroid dose administered from days 0 to 7 which was higher than those without BKV DNAemia (2.13 +/- 0.6 vs 1.6 +/- 0.4; P = .024). The first BKV DNAemia occurred at 170 (30-460) days posttransplantation. Of the 7 patients who experienced at least 1 BKV DNAemia, 3 had 1 occurrence, but the other 4 had repeated occurrences. These 4 patients developed overt BKVAN at 1 (2 cases) to 2 weeks (2 cases) after the first occurrence of BKV DNAemia. These 4 patients were withdrawn from mycophenolate mofetil, which was in all cases replaced by leflunomide. With a follow-up ranging from 14 to 24 months after the first episode of BKV DNAemia, patient and graft survivals were both 100%. Current serum creatinine ranges from 97 to 173 micro mol/L for those who had only 1 episode of BKV DNAemia, and from 144 to 240 micro mol/L for those who had overt BKVAN.

CONCLUSION

Although BKV DNAemia is a rare event after renal transplantation, it is often associated with BKVAN, which may be treated successfully by the alleviation of immunosuppression and leflunomide therapies.

Predictive factors for cytomegalovirus infection after orthotopic liver transplantation using an ultrasensitive polymerase chain reaction assay

The predictive factors for cytomegalovirus (CMV) infection in de novo liver transplant patients were determined at 3 months posttransplantation. We included all consecutive patients except those who died or who had lost their graft within 1 month posttransplant. We recorded both donor (D) and recipient (R) data. Immunosuppression utilized tacrolimus, steroids, with or without mycophenolate mofetil, and/or induction therapy with anti-CD25 monoclonal antibodies. CMV prophylaxis was administered only to those at high risk of CMV infection, namely, D+/R- patients. These cases received intravenous ganciclovir at 500 mg/d for the first 2 weeks followed by oral ganciclovir at 500 mg for the following 3 months. The median time to CMV infection was 1 month. The significant predictive factors for CMV infection were D/R CMV status, (P = .002): D+/R+ versus other patients (P = .01), D-/R- versus other patients (P = .002), D+ versus D- (P = .009). In addition infection was associated with the original liver disease (hepatitis C virus infection or alcohol-related cirrhosis; P = .03), R+ vs. R- (P = .03), donor age (<45 or >45 years; P = .01), lymphocyte count at M2 (< or >1300/mm(3); P = .02), hemoglobin levels at 1 and 3 months, and platelet and white blood cell counts at day 7. The independent predictive factors were recipient CMV sero-status (R+ vs R-; odds ratio = 10.2), donor age >45 years (odds ratio = 11.4) and lymphocyte count at M2 <1300/mm(3) (odds ratio = 7.33). This study showed that the major factors associated with CMV infection were recipient CMV status, donor age, and lymphocyte count.

Rituximab therapy for mixed cryoglobulinemia in seven renal transplant patients

Systemic B-cell depletion and clinical remission of the systemic effects of cryoglobulins have been achieved in hepatitis C virus-positive immunocompetent patients with rituximab, a human/mouse chimeric monoclonal antibody that specifically reacts with the CD20 antigen. Thus, this provides a rationale for the use of rituximab for type III cryoglobulin-related graft dysfunction in renal-transplant patients. Seven patients, of whom five were hepatitis C positive, developed renal function impairment long after transplantation, as well as de novo nephrotic syndrome (n = 5), severe hypertension (n = 5), nephritic syndrome (n = 1), and increased serum creatinine (n = 1). This type III cryoglobulinemia was associated with membranoproliferative glomerulonephritis and with thrombi within the glomeruli in one case. In addition to their baseline standard immunosuppressive medications, the patients were given weekly rituximab infusions: 375 mg/m(2) for 2 weeks in four cases, for 3 weeks in one case, and for 4 weeks in two cases. This treatment resulted in a dramatic improvement in all renal parameters, particularly a sustained remission of nephrotic syndrome in three cases, the disappearance of nephritic syndrome in one patient, and improved nephrotic syndrome in two cases, as well as a sustained clearance of cryoglobulins in six cases. However, it also resulted in severe infectious complications in two cases. We concluded that rituximab therapy is effective in cryoglobulin-related renal dysfunction in renal transplant patients but, due to chronic immunosuppression, this may be achieved at the expense of infectious complications.

Monitoring HCMV Infection With Quantitative Real-Time PCR in HCMV-Positive Orthotopic Liver Transplant Recipients, and Predictive Factors for Treatment of the First Episode of HCMV Viremia

We evaluated the relevance of human cytomegalovirus (HCMV) monitoring with quantitative real-time polymerase chain reaction in 42 consecutive HCMV positive liver transplant patients, and we analyzed the factors that determined the treatment of the first episode of HCMV DNAemia. No patients received anti-HCMV prophylaxis. HCMV infection monitoring was assessed every 2 weeks until day 90 and thereafter at every 3 to 4 weeks until day 180. HCMV infection was detected among 27 patients (64%, ie, 92/380 samples). Of these, 12 had their first HCMV DNAemia treated with IV gancyclovir (group I), whereas the other 15 patients were not treated (group II). Immunosuppressive treatment was not modified in cases of HCMV DNAemia. The median time between transplantation to the first CMV DNAemia was 37 days in group I and 52 days in group II (NS). Median HCMV viral load, whatever the treatment group and whatever the time of DNAemia, was 3 log copies/mL (0.48 to 5.80). Median HCMV viral load of the first positive DNAemia was 3.45 log copies/mL (1.69 to 5.80) in group I and 2.70 log copies/mL (1.15 to 3.94) in group II (P = .01). Even though liver enzymes were increased in almost all patients presenting with HCMV infection, comparison of liver-enzyme levels and hematological parameters between the two groups at first HCMV viremia showed that alkaline phosphatase levels were significantly higher (P = .0011) and hemoglobin levels were significantly lower in group I patients (P = .0443). The only factor that predicted treatment for the first episode of HCMV DNAemia was an alkaline phosphatase level >150 UI/mL at the time of the first HCMV reactivation [odds ratio 20 (1.96 to 203.3); P = .01].