Elisabetta Calore

Extracorporeal photochemotherapy for paediatric patients with graft‐versus‐host disease after haematopoietic stem cell transplantation

Summary. This study aimed to ascertain whether extracorporeal photochemotherapy (ECP) is an effective treatment for paediatric patients with refractory graft‐versus‐host disease (GVHD). From January 1992 to December 2000, 77 children (median age 8·6 years) with either acute (n = 33) or chronic (n = 44) GVHD, resistant to conventional immunosuppressive therapy, were treated with ECP in four Italian paediatric hospitals. After ECP, acute GVHD involving skin, liver and gut responded completely in 76%, 60% and 75% of patients respectively. The 5‐year overall survival was 69% for responding patients vs 12% for non‐responders (P = 0·001). Among the 44 children with chronic GVHD, 15 (44%) showed a complete response and 10 (29%) a significant improvement after ECP. The 5‐year overall survival was 96% for responders vs 58% for non‐responders (P = 0·04). Our results suggest that ECP is an effective treatment that may be useful in paediatric patients with either acute or chronic GVHD who have failed to respond to standard immunosuppressive therapy.

Human polyomavirus BK (BKV) load and haemorrhagic cystitis in bone marrow transplantation patients

Several observations suggest an association between long-lasting haemorrhagic cystitis (HC) in bone marrow transplantation (BMT) recipients and human polyomavirus BK (BKV) reactivation, but no conclusive evidence has been obtained so far. The amount of BKV measured in the urine of BMT patients during an episode of HC was compared with that detected in the urine of BMT patients without HC and of immunocompetent individuals in order to better assess the association of BKV reactivation with HC. For this purpose a quantitative competitive PCR was developed. The application of this assay to clinical samples allowed us to distinguish asymptomatic reactivation both in healthy individuals and in immunocompromised patients from reactivation associated with HC, in almost all cases. Low levels, below the sensitivity of the quantitative assay, were shown in asymptomatic healthy individuals and in about 50% of immunocompromised patients. A significantly higher viral load than in the urine of asymptomatic immunocompromised patients was detected in the urine of patients with HC. These data strengthen the hypothesis that BKV reactivation can cause, together with other factors, the majority of late HC in BMT recipients as well as in patients treated for acute refractory lymphoblastic leukemia.

A prospective study of BK-virus-associated haemorrhagic cystitis in paediatric patients undergoing allogeneic haematopoietic stem cell transplantation

We investigated the incidence, risk factors and outcome of haemorrhagic cystitis (HC) in paediatric patients undergoing HSCT and the predictive value of BK viruria and viraemia for developing HC. Over a period of 54 months, 74 patients were recruited. The cumulative incidence of HC was 22%. Among 15 patients prospectively monitored for BK viruria and viraemia, four patients developed HC of grade ⩾II. This group, which had two consecutive BK positive samples, showed a sensitivity of 100%, a specificity of 82%, a positive predictive value of 67%, and negative predictive value of 100% for developing HC. Analysed by a receiver–operator characteristic curve (ROC), a urine BK load >9 × 106 genomic copies/ml had a sensitivity of 95% and specificity of 90%; while a blood BK load >1 × 103 genomic copies/ml had a sensitivity of 40% and a specificity of 93% for HC, respectively. In univariate analysis, BK positivity was the only factor significantly associated with HC. After a median follow-up of 1.8 years, patients with HC showed a lower overall survival, 40 vs 65%, P 0.01, and a lower event-free survival, 42 vs 62%, P 0.03, compared to patients without HC. We conclude that BK detection in urine and/or plasma is a specific predictor for developing HC.

Extracorporeal photochemotherapy may improve outcome in children with acute GVHD

Acute GVHD (aGVHD) is a major cause of morbidity and mortality after unrelated BMT (UBMT). Our purpose was to analyze the role of extracorporeal photochemotherapy (ECP) in controlling grade II–IV aGVHD in children given UBMT. Of 41 consecutive children, 31 developed grade II–IV aGVHD after UBMT: 16 had a good response to steroids (GR group), whereas 15 underwent ECP (ECP group) within 100 days of UBMT. Eligibility criteria for starting ECP were steroid resistance, dependence or viral reactivations. Criteria for judging response to aGVHD treatment were that the resolution of all signs were considered a complete response (CR), at least a 50% improvement was classified as a partial response (PR) and stable or progressive disease was judged as no response (NR). On completing ECP, the CR rate was 73%, whereas the GR group had a CR rate of 56% by day 100. The 2-year overall survival and progression-free survival rates were 57 and 67% in the GR group vs 85 and 87% in the ECP group. Our data seem to suggest that ECP may improve outcome in patients after UBMT. These findings need to be confirmed in a larger population.

Safety and efficacy of caspofungin and liposomal amphotericin B, followed by voriconazole in young patients affected by refractory invasive mycosis

Abstract:  Objective: Data on the use of combination of liposomal amphotericin B and caspofungin followed by voriconazole, as maintenance or further rescue treatment, in 10 patients with invasive mycosis are reported. Material and methods: The diagnoses were acute leukemia (7), myelodysplastic syndrome (1) and Hodgkins lymphoma (1). All patients developed an invasive mycosis (proven, 3; probable, 6; and possible, 1) refractory to first‐line antifungal treatment (liposomal amphotericin B in all patients except one who received fluconazole). Results: Rescue therapy with a combination of caspofungin and liposomal amphotericin B was well tolerated, hypokalemia, and thrombophlebitis being the most common side‐effects. Combination therapy was administered for a median of 17 d, range 6–40. Among the nine patients with proven or probable mycosis, one was not evaluated because of early death caused by massive hemoptysis whilst in the remaining eight patients, the response was classified as complete, stable and failure in four, three, and one patients, respectively. Complete response was also observed in patient with possible mycosis. Eight of nine patients received voriconazole for a median of 75 d, range 42–194. Voriconazole was well tolerated although some drug interactions were observed during treatment with methotrexate and digoxin. After a median follow‐up of 125 d, nine of 10 patients are alive. Overall, a favorable response to antifungal treatment (including the case of possible mycosis) was obtained in eight of 10 patients. Conclusion: These data suggest that medical antifungal treatment may be intensified in severely ill patients without significantly compromising patient safety. The combination of synergistic antifungal drugs as well as their sequential use warrants further investigation by a larger randomized controlled study.

The real-time polymerase chain reaction-guided modulation of immunosuppression enables the pre-emptive management of Epstein-Barr virus reactivation after allogeneic haematopoietic stem cell transplantation.

To assess a real‐time polymerase chain reaction‐based modulation of immunosuppression in patients with an increasing Epstein–Barr virus (EBV) viral load, we studied 79 paediatric allogeneic stem cell transplantations (allo‐SCT) performed between January 1998 and December 2003. EBV reactivation was observed in 42 of 79 patients (53%) after a median time of 45 d from allo‐SCT: 37 (88%) and five (12%) patients had received the graft from an unrelated and a related donor respectively (P = 0·001). Twenty‐eight patients (67%) had a viral load ≥300 genomic copies ×105 peripheral blood mononuclear cells (PBMC) and antithymocyte globulin was the only factor significantly associated with EBV reactivation (P = 0·001, RR 7·1). Among these 28 patients, immunosuppression was suspended and reduced in 17 and 11 patients respectively. Overall, post‐transplant lymphoproliferative disease was diagnosed in one of 79 patients (1%). The pre‐emptive modulation of immunosuppression in patients with EBV reactivation and a viral load ≥300 genomic copies ×105 PBMC did not negatively influence transplant‐related mortality, overall survival or event‐free survival. In conclusion, EBV reactivation is frequent even in ‘low risk’ patients and the pre‐emptive modulation of immunosuppression enables it to be managed safely, with no significant flare in graft‐versus‐host disease status.

Prevention and treatment of acute GvHD.

GvHD remains a source of significant morbidity and mortality in the setting of allogeneic haematopoietic SCT. Improving outcomes in stem cell transplant recipients requires additional therapeutic modalities for GvHD, especially for patients who fail to respond to initial therapy with steroids. Moreover, while the absence of acute GvHD (aGvHD) is associated with a higher risk of relapse of the underlying malignant disease, severe aGvHD usually induces the occurrence of life-threatening complications such as severe infections. This article summarizes the current state of aGvHD prophylaxis and treatment.

Assessment of the lightcycler PCR assay for diagnosis of invasive aspergillosis in paediatric patients with onco-haematological diseases

A reliable diagnosis of invasive aspergillosis (IA) is hampered by the difficulty in obtaining suitable tissue samples. To evaluate the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the LightCycler PCR for the diagnosis of IA, 536 blood samples were collected over a 22‐month period from 62 paediatric patients (median age 10 years, range 1–18) considered at risk of IA. The galactomannan antigen (GM) and fungal DNA were assessed on serial blood samples. IA was diagnosed in eight of 62 patients (13%): proven, five, probable, three. Sensitivity, specificity, PPV and NPV of LightCycler PCR varied according to the number of positive samples used to define positivity: 88%; 37%; 17% and 95% for single sample positivity; and 63%, 81%, 33% and 94% for serial sample positivity respectively. The concordance between positivity of LightCycler PCR assay and the diagnosis of IA was 79%. The single positivity of LightCycler PCR assay showed a good sensitivity for the diagnosis of IA in paediatric patients. The high NPV makes LightCycler PCR a promising tool in addition to GM testing to design a strategy of pre‐emptive antifungal therapy, although further validation studies are needed.

A Prospective Study on Modulation of Immunosuppression for Epstein-Barr Virus Reactivation in Pediatric Patients Who Underwent Unrelated Hematopoietic Stem-Cell Transplantation

Background. Posttransplant lymphoproliferative disease caused by Epstein-Barr virus (EBV-PTLD) is a severe complication after allogeneic hematopoietic stem-cell transplantation (HSCT). We evaluated whether the modulation of immunosuppression (IS) guided by quantitative polymerase chain reaction for EBV (EBV-PCR) was effective as a first-line therapeutic approach for EBV reactivation. Methods. Eighty-nine pediatric patients who received an HSCT from an unrelated donor were prospectively assessed by quantitative EBV-PCR. The EBV-PCR threshold to modulate IS was set to more than 300 genomic copies (gc)/105 peripheral blood mononuclear cells. Results. EBV-PCR positivity was observed in 56 (63%) of 89 patients at a median time of 44 days after HSCT. The variables associated with EBV-PCR positivity were bone marrow stem cells (P=0.047) and a lower total dose of nuclear cells reinfused (P=0.03). Thirty-one patients (35%) had more than or equal to 300 gc. IS was withdrawn or reduced in 18 (58%) and 13 (42%) of the 31 patients, respectively. EBV viral load (EBV-VL) less than 300 gc was achieved in 30 of these 31 patients at a median of 25 days. Only 1 (1%) of the 89 patients progressed to EBV-PTLD. The patients with EBV-VL more than 300 gc had a lower incidence of acute graft versus host disease III-IV than patients with EBV-VL less than 300 gc: 13% vs. 36%, P=0.02. No differences in terms of chronic graft versus host disease, overall survival, event-free survival and transplant-related mortality were observed between the two groups. Conclusions. We conclude that PCR-guided modulation of IS may play a role in early intervention for EBV-PTLD and a prospective, randomized study is needed.

Diagnostic utility of human cytomegalovirus-specific T-cell response monitoring in predicting viremia in pediatric allogeneic stem-cell transplant patients

Background. Several studies proved that virus-specific T-cells play a pivotal role in controlling cytomegalovirus (CMV) infection in adult allogeneic hematopoietic stem-cell transplant (HSCT) patients. Fewer data are available in pediatric HSCT settings, when immature and inexperienced immune system may affect antiviral immune reconstitution. Methods. We analyzed prospectively the CMV-specific T-cell reconstitution in a cohort of 31 pediatric allogeneic HSCT recipients at 30, 60, 90, 120, 180, and 360 days after HSCT. Results. Depending on donor-recipient CMV serostatus, we observed distinct patterns and kinetics of CMV-specific T-cell immune reconstitution: during the early time-points, patients displayed a severe reduction in CMV-specific T-cell recovery in both CMV seropositive donor (D+) group and CMV seronegative donor (D−) on CMV seropositive recipients (R+). From day 90 onward, statistical significant differences in the profile of T-cell immune reconstitution emerged between D+ and D−. The pattern of immune reconstitution was characterized by heterogeneous kinetics and efficiencies: we report cases of: (1) spontaneous antiviral T-cell recovery with no previous viremia, (2) immune T-cell recovery anticipated by CMV viremia, and (3) no T-cell immune reconstitution despite previous viremia episodes. Conclusions. Given the heterogeneous scenarios of antiviral T-cell immune recovery in pediatric allogeneic HSCT, we conclude that the evaluation of the antiviral immune reconstitution is a promising and appealing system for identifying patients at higher risk of CMV infection. The use of interferon-&ggr; ELISPOT test is a valid tool for immunological monitoring and predicting CMV viremia in pediatric HSCT.