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Dive into the research topics where Ramon Del Busto is active.

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Featured researches published by Ramon Del Busto.


Transplantation | 2006

Combination of voriconazole and caspofungin as primary therapy for invasive aspergillosis in solid organ transplant recipients: a prospective, multicenter, observational study.

Nina Singh; Ajit P. Limaye; Graeme N. Forrest; Nasia Safdar; Patricia Muñoz; Kenneth Pursell; Sally Houston; Fernando Rosso; Jose G. Montoya; Pamela R. Patton; Ramon Del Busto; José María Aguado; Robert A. Fisher; Goran B. Klintmalm; Rachel Miller; Marilyn M. Wagener; Russell E. Lewis; Dimitrios P. Kontoyiannis; Shahid Husain

Background. The efficacy of the combination of voriconazole and caspofungin when used as primary therapy for invasive aspergillosis in organ transplant recipients has not been defined. Methods. Transplant recipients who received voriconazole and caspofungin (n=40) as primary therapy for invasive aspergillosis (proven or probable) in a prospective multicenter study between 2003 and 2005 were compared to a control group comprising a cohort of consecutive transplant recipients between 1999 and 2002 who had received a lipid formulation of AmB as primary therapy (n=47). In vitro antifungal testing of Aspergillus isolates to combination therapy was correlated with clinical outcome. Results. Survival at 90 days was 67.5% (27/40) in the cases, and 51% (24/47) in the control group (HR 0.58, 95% CI, 0.30–1.14, P=0.117). However, in transplant recipients with renal failure (adjusted HR 0.32, 95% CI: 0.12–0.85, P=0.022), and in those with A. fumigatus infection (adjusted HR 0.37, 95% CI: 0.16–0.84, P=0.019), combination therapy was independently associated with an improved 90-day survival in multivariate analysis. No correlation was found between in vitro antifungal interactions of the Aspergillus isolates to the combination of voriconazole and caspofungin and clinical outcome. Conclusions. Combination of voriconazole and caspofungin might be considered preferable therapy for subsets of organ transplant recipients with invasive aspergillosis, such as those with renal failure or A. fumigatus infection.


Clinical Infectious Diseases | 2005

An immune reconstitution syndrome-like illness associated with Cryptococcus neoformans infection in organ transplant recipients.

Nina Singh; Olivier Lortholary; Barbara D. Alexander; Krishan L. Gupta; George T. John; Kenneth Pursell; Patricia Muñoz; Goran B. Klintmalm; Valentina Stosor; Ramon Del Busto; Ajit P. Limaye; Jyoti Somani; Marshall Lyon; Sally Houston; Andrew A. House; Timothy L. Pruett; Susan L. Orloff; Atul Humar; Lorraine A. Dowdy; Julia Garcia-Diaz; Andre C. Kalil; Robert A. Fisher; Shahid Husain

BACKGROUND We describe an immune reconstitution syndrome (IRS)-like entity in the course of evolution of Cryptococcus neoformans infection in organ transplant recipients. METHODS The study population comprised a cohort of 83 consecutive organ transplant recipients with cryptococcosis who were observed for a median of 2 years in an international, multicenter study. RESULTS In 4 (4.8%) of the 83 patients, an IRS-like entity was observed a median of 5.5 weeks after the initiation of appropriate antifungal therapy. Worsening of clinical manifestations was documented, despite cultures being negative for C. neoformans. These patients were significantly more likely to have received tacrolimus, mycophenolate mofetil, and prednisone as the regimen of immunosuppressive therapy than were all other patients (P = .007). The proposed basis of this phenomenon is reversal of a predominantly Th2 response at the onset of infection to a Th1 proinflammatory response as a result of receipt of effective antifungal therapy and a reduction in or cessation of immunosuppressive therapy. CONCLUSIONS This study demonstrated that an IRS-like entity occurs in organ transplant recipients with C. neoformans infection. Furthermore, this entity may be misconstrued as a failure of therapy. Immunomodulatory agents may have a role as adjunctive therapy in such cases.


The Journal of Infectious Diseases | 2007

Cryptococcus neoformans in Organ Transplant Recipients: Impact of Calcineurin-Inhibitor Agents on Mortality

Nina Singh; Barbara D. Alexander; Olivier Lortholary; Françoise Dromer; Krishan L. Gupta; George T. John; Ramon Del Busto; Goran B. Klintmalm; Jyoti Somani; G. Marshall Lyon; Kenneth Pursell; Valentina Stosor; Patricia Muňoz; Ajit P. Limaye; Andre C. Kalil; Timothy L. Pruett; Julia Garcia-Diaz; Atul Humar; Sally Houston; Andrew A. House; Dannah Wray; Susan L. Orloff; Lorraine A. Dowdy; Robert A. Fisher; Joseph Heitman; Marilyn M. Wagener; Shahid Husain; Corinne Antoine; Barrou Benoît; Anne Elisabeth Heng

Variables influencing the risk of dissemination and outcome of Cryptococcus neoformans infection were assessed in 111 organ transplant recipients with cryptococcosis in a prospective, multicenter, international study. Sixty-one percent (68/111) of the patients had disseminated infection. The risk of disseminated cryptococcosis was significantly higher for liver transplant recipients (adjusted hazard ratio [HR], 6.65; P=.048). The overall mortality rate at 90 days was 14% (16/111). The mortality rate was higher in patients with abnormal mental status (P=.023), renal failure at baseline (P=.028), fungemia (P=.006), and disseminated infection (P=.035) and was lower in those receiving a calcineurin-inhibitor agent (P=.003). In a multivariable analysis, the receipt of a calcineurin-inhibitor agent was independently associated with a lower mortality (adjusted HR, 0.21; P=.008), and renal failure at baseline with a higher mortality rate (adjusted HR, 3.14; P=.037). Thus, outcome in transplant recipients with cryptococcosis appears to be influenced by the type of immunosuppressive agent employed. Additionally, discerning the basis for transplant type-specific differences in disease severity has implications relevant for yielding further insights into the pathogenesis of C. neoformans infection in transplant recipients.


Clinical Infectious Diseases | 2008

Pulmonary Cryptococcosis in Solid Organ Transplant Recipients: Clinical Relevance of Serum Cryptococcal Antigen

Nina Singh; Barbara D. Alexander; Olivier Lortholary; Françoise Dromer; Krishan L. Gupta; George T. John; Ramon Del Busto; Goran B. Klintmalm; Jyoti Somani; G. Marshall Lyon; Kenneth Pursell; Valentina Stosor; Patricia Muñoz; Ajit P. Limaye; Andre C. Kalil; Timothy L. Pruett; Julia Garcia-Diaz; Atul Humar; Sally Houston; Andrew A. House; Dannah Wray; Susan L. Orloff; Lorraine A. Dowdy; Robert A. Fisher; Joseph Heitman; Marilyn M. Wagener; Shahid Husain

BACKGROUND The role of serum cryptococcal antigen in the diagnosis and determinants of antigen positivity in solid organ transplant (SOT) recipients with pulmonary cryptococcosis has not been fully defined. METHODS We conducted a prospective, multicenter study of SOT recipients with pulmonary cryptococcosis during 1999-2006. RESULTS Forty (83%) of 48 patients with pulmonary cryptococcosis tested positive for cryptococcal antigen. Patients with concomitant extrapulmonary disease were more likely to have a positive antigen test result (P=.018), and antigen titers were higher in patients with extrapulmonary disease (P=.003) or fungemia (P=.045). Patients with single nodules were less likely to have a positive antigen test result than were those with all other radiographic presentations (P=.053). Among patients with isolated pulmonary cryptococcosis, lung transplant recipients were less likely to have positive cryptococcal antigen test results than were recipients of other types of SOT (P=.003). In all, 38% of the patients were asymptomatic or had pulmonary cryptococcosis detected as an incidental finding. Nodular densities or mass lesions were more likely to present as asymptomatic or incidentally detected pulmonary cryptococcosis than as pleural effusions and infiltrates (P=.008). CONCLUSIONS A positive serum cryptococcal antigen test result in SOT recipients with pulmonary cryptococcosis appears to reflect extrapulmonary or more advanced radiographic disease.


Antimicrobial Agents and Chemotherapy | 2008

Calcineurin Inhibitor Agents Interact Synergistically with Antifungal Agents In Vitro against Cryptococcus neoformans Isolates: Correlation with Outcome in Solid Organ Transplant Recipients with Cryptococcosis

Dimitrios P. Kontoyiannis; Russell E. Lewis; Barbara D. Alexander; Olivier Lortholary; Françoise Dromer; Krishan L. Gupta; George T. John; Ramon Del Busto; Goran B. Klintmalm; Jyoti Somani; G. Marshall Lyon; Kenneth Pursell; Valentina Stosor; Patricia Muňoz; Ajit P. Limaye; Andre C. Kalil; Timothy L. Pruett; Julia Garcia-Diaz; Atul Humar; Sally Houston; Andrew A. House; Dannah Wray; Susan L. Orloff; Lorraine A. Dowdy; Robert A. Fisher; Joseph Heitman; Nathaniel D. Albert; Marilyn M. Wagener; Nina Singh

ABSTRACT Synergistic interactions were observed between CIs and antifungal agents against 53 (90%) of 59 Cryptococcus neoformans isolates from solid organ transplant recipients with cryptococcosis and may account for better outcomes in patients with cryptococcosis receiving these immunosuppressive agents.


Transplantation | 2005

Antifungal management practices and evolution of infection in organ transplant recipients with cryptococcus neoformans infection.

Nina Singh; Olivier Lortholary; Barbara D. Alexander; Krishan L. Gupta; George T. John; Kenneth Pursell; Patricia Muñoz; Goran B. Klintmalm; Valentina Stosor; Ramon Del Busto; Ajit P. Limaye; Jyoti Somani; Marshall Lyon; Sally Houston; Andrew A. House; Timothy L. Pruett; Susan L. Orloff; Atul Humar; Lorraine A. Dowdy; Julia Garcia-Diaz; Andre C. Kalil; Robert A. Fisher; Joseph Heitman; Shahid Husain

Background. Therapeutic practices for Cryptococcus neoformans infection in transplant recipients vary, particularly with regards to antifungal agent employed, and duration of therapy. The risk of relapse and time to recurrence is not known. We assessed antifungal treatment practices for cryptococcosis in a cohort of prospectively followed organ transplant recipients. Methods. The patients comprised 83 transplant recipients with cryptococcosis followed for a median of 2.1 and up to 5.2 years. Results. Patients with central nervous system infection (69% vs. 16%, P = 0.00001), disseminated infection (82.7% vs. 20%, P = 0.00001), and fungemia (29% vs. 8%, P = 0.046) were more likely to receive regimens containing amphotericin B than fluconazole as primary therapy. The use of fluconazole, on the other hand, was more likely for infection limited to the lungs (64% vs. 14%, P = 0.00002). Survival at 6 months tended to be lower in patients whose CSF cultures at 2 weeks were positive compared to those whose CSF cultures were negative (50% vs. 91%, P = 0.06). Maintenance therapy was employed in 68% (54/79) of the patients who survived >3 weeks. The median duration of maintenance therapy was 183 days; 55% received maintenance for ≥ 6 months and 25% for >1 year. Relapse was documented in 1.3% (1/79) of the patients. Conclusions. A majority of the organ transplant recipients with cryptococcosis receive maintenance antifungal therapy for 6 months with low risk of relapse. These data can assist in trials to assess the optimal therapeutic approach and duration of therapy for cryptococcosis in transplant recipients.


Medical Mycology | 2006

Late-onset invasive aspergillosis in organ transplant recipients in the current era

Nina Singh; Ajit P. Limaye; Graeme N. Forrest; Nasia Safdar; Patricia Muñoz; Kenneth Pursell; Sally Houston; Fernando Rosso; Jose G. Montoya; Pamela R. Patton; Ramon Del Busto; José María Aguado; Marilyn M. Wagener; Shahid Husain

We assessed predictive factors and characteristics of patients with late-onset invasive aspergillosis in the current era of novel immunosuppressive agents. Forty transplant recipients with invasive aspergillosis were included in this prospective, observational study initiated in 2003 at our institutions. In 50% (20/40) of these patients, the infections were late-occurring. Receipt of sirolimus in conjunction with tacrolimus for refractory rejection or cardiac allograft vasculopathy (P=0.047) was significantly associated with late-onset infection. The use of depleting or non-depleting T or B-cell antibodies, either as induction or as antirejection therapy did not correlate with time to onset of invasive aspergillosis. Mortality at 90 days was 20% (4/20) for the patients with early-onset infection and 45% (9/20) for those with late-onset infection (P=0.17). Thus, nearly one-half of the Aspergillus infections in transplant recipients in the current era are late-occurring. These data have implications relevant for prophylactic strategies and guiding clinical management of transplant recipients presenting with pulmonary infiltrates.


Transplantation | 2008

Central Nervous System Cryptococcosis in Solid Organ Transplant Recipients : Clinical Relevance of Abnormal Neuroimaging Findings

Nina Singh; Olivier Lortholary; Françoise Dromer; Barbara D. Alexander; Krishan L. Gupta; George T. John; Ramon Del Busto; Goran B. Klintmalm; Jyoti Somani; G. Marshall Lyon; Kenneth Pursell; Valentina Stosor; Patricia Muňoz; Ajit P. Limaye; Andre C. Kalil; Timothy L. Pruett; Julia Garcia-Diaz; Atul Humar; Sally Houston; Andrew A. House; Dannah Wray; Susan L. Orloff; Lorraine A. Dowdy; Robert A. Fisher; Joseph Heitman; Marilyn M. Wagener; Shahid Husain

Background. Prognostic implications of cryptococcal antigen and outcomes associated with central nervous system (CNS) cryptococcal lesions in solid organ transplant recipients have not been fully defined. Methods. Patients were derived form a cohort of 122 solid organ transplant recipients with cryptococcosis in a multicenter study from 1999 to 2006. Results. Central nervous system cryptococcosis was documented in 61 patients. Serum or cerebral spinal fluid antigen titers did not correlate with mortality at 90 days or cerebral spinal fluid sterilization at 2 weeks. Central nervous system lesions were identified in 16 patients and included leptomeningeal lesions in eight, parenchymal lesions in six, and hydrocephalus in two. Overall, 13/16 CNS lesions were present at the time of diagnosis. One parenchymal and two hydrocephalus lesions, however, developed after diagnosis and fulfilled the criteria for immune reconstitution syndrome. Cerebral spinal fluid antigen titers were higher with meningeal versus parenchymal lesions, and hydrocephalus (P=0.015). Mortality was 50% (3/6) for patients with parenchymal, 12.5% (1/8) for those with leptomeningeal, and 0/3 for patients with hydrocephalus. Mortality was 31% (4/13) for patients with CNS lesions at baseline and 0/3 in those with new onset lesions. Conclusions. Despite a higher antigen titer with meningeal lesions, outcomes tended to be worse with parenchymal compared with meningeal lesions or hydrocephalus. New onset CNS lesions may represent immune reconstitution syndrome and seemed to be associated with better outcome.


Clinical Infectious Diseases | 2010

Unrecognized pretransplant and donor derived cryptococcal disease in organ transplant recipients.

Hsin-Yun Sun; Barbara D. Alexander; Olivier Lortholary; Françoise Dromer; Graeme N. Forrest; G. Marshall Lyon; Jyoti Somani; Krishan L. Gupta; Ramon Del Busto; Timothy L. Pruett; Costi D. Sifri; Ajit P. Limaye; George T. John; Goran B. Klintmalm; Kenneth Pursell; Valentina Stosor; Michele I. Morris; Lorraine A. Dowdy; Patricia Muñoz; Andre C. Kalil; Julia Garcia-Diaz; Susan L. Orloff; Andrew A. House; Sally Houston; Dannah Wray; Shirish Huprikar; Leonard B. Johnson; Atul Humar; Raymund R. Razonable; Robert A. Fisher

BACKGROUND Cryptococcosis occurring ≤30 days after transplantation is an unusual event, and its characteristics are not known. METHODS Patients included 175 solid-organ transplant (SOT) recipients with cryptococcosis in a multicenter cohort. Very early-onset and late-onset cryptococcosis were defined as disease occurring ≤30 days or >30 days after transplantation, respectively. RESULTS Very early-onset disease developed in 9 (5%) of the 175 patients at a mean of 5.7 days after transplantation. Overall, 55.6% (5 of 9) of the patients with very early-onset disease versus 25.9% (43 of 166) of the patients with late-onset disease were liver transplant recipients (P = .05). Very early cases were more likely to present with disease at unusual locations, including transplanted allograft and surgical fossa/site infections (55.6% vs 7.2%; P < .001). Two very early cases with onset on day 1 after transplantation (in a liver transplant recipient with Cryptococcus isolated from the lung and a heart transplant recipient with fungemia) likely were the result of undetected pretransplant disease. An additional 5 cases involving the allograft or surgical sites were likely the result of donor‐acquired infection. CONCLUSIONS A subset of SOT recipients with cryptococcosis present very early after transplantation with disease that appears to occur preferentially in liver transplant recipients and involves unusual sites, such as the transplanted organ or the surgical site. These patients may have unrecognized pretransplant or donor-derived cryptococcosis.


Clinical Infectious Diseases | 2009

Lipid formulations of Amphotericin B significantly improve outcome in solid organ transplant recipients with central nervous system Cryptococcosis

Hsin-Yun Sun; Barbara D. Alexander; Olivier Lortholary; Françoise Dromer; Graeme N. Forrest; G. Marshall Lyon; Jyoti Somani; Krishan L. Gupta; Ramon Del Busto; Timothy L. Pruett; Costi D. Sifri; Ajit P. Limaye; George T. John; Goran B. Klintmalm; Kenneth Pursell; Valentina Stosor; Michelle I. Morris; Lorraine A. Dowdy; Patricia Muñoz; Andre C. Kalil; Julia Garcia-Diaz; Susan L. Orloff; Andrew A. House; Sally Houston; Dannah Wray; Shirish Huprikar; Leonard B. Johnson; Atul Humar; Raymund R. Razonable; Shahid Husain

BACKGROUND Whether outcome of central nervous system (CNS) cryptococcosis in solid organ transplant recipients treated with lipid formulations of amphotericin B is different from the outcome of the condition treated with amphotericin B deoxycholate (AmBd) is not known. METHODS We performed a multicenter study involving a cohort comprising consecutive solid organ transplant recipients with CNS cryptococcosis. RESULTS Of 75 patients treated with polyenes as induction regimens, 55 (73.3%) received lipid formulations of amphotericin B and 20 (26.7%) received AmBd. Similar proportions of patients in both groups had renal failure at baseline (P = .94 ). Overall, mortality at 90 days was 10.9% in the group that received lipid formulations of amphotericin B and 40.0% in the group that received AmBd. In univariate analysis, nonreceipt of calcineurin inhibitors (P = .034), renal failure at baseline (P = .016), and fungemia (P = .003) were significantly associated with mortality. Compared with AmBd, lipid formulations of amphotericin B were associated with a lower mortality (P = .007). Mortality did not differ between patients receiving lipid formulations of amphotericin B with or without flucytosine (P = .349). In stepwise logistic regression analysis, renal failure at baseline (odds ratio [OR], 4.61; 95% confidence interval [CI], 1.02-20.80; P = .047) and fungemia (OR, 10.66; 95% CI, 2.08-54.55; P = .004 ) were associated with an increased mortality, whereas lipid formulations of amphotericin B were associated with a lower mortality (OR, 0.11; 95% CI, 0.02-0.57; P = .008). CONCLUSIONS Lipid formulations of amphotericin B were independently associated with better outcome and may be considered as the first-line treatment for CNS cryptococcosis in these patients.

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Ajit P. Limaye

University of Washington

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Sally Houston

University of South Florida

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Goran B. Klintmalm

Baylor University Medical Center

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Andre C. Kalil

University of Nebraska–Lincoln

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