Clarisse Martins Machado

Low mortality rates related to respiratory virus infections after bone marrow transplantation.

Summary:Respiratory viruses (RVs) frequently cause severe respiratory disease in bone marrrow transplant (BMT) recipients. To evaluate the frequency of RV, nasal washes were collected year-round from BMT recipients with symptoms of upper respiratory tract infection (URI). Direct immunofluorescence assay was performed for respiratory syncytial virus (RSV), influenza (Flu) A and B, adenovirus and parainfluenza (Paraflu) virus. Patients with RSV pneumonia or with upper RSV infection, but considered at high risk for developing RSV pneumonia received aerosolized ribavirin. Oseltamivir was given to patients with influenza. A total of 179 patients had 392 episodes of URI. In all, 68 (38%) tested positive: RSV was detected in 18 patients (26.4%), Flu B in 17 (25%), Flu A in 11 (16.2%) and Paraflu in 7 (10.3%). A total of 14 patients (20.6%) had multiple RV infections or coinfection. RSV pneumonia developed in 55.5% of the patients with RSV-URI. One of the 15 patients (6.6%) with RSV pneumonia died. Influenza pneumonia was diagnosed in three patients (7.3%). RSV and influenza infections peaked in fall–winter and winter–spring months, respectively. We observed decreased rates of influenza and parainfluenza pneumonia and low mortality because of RSV pneumonia. The role of antiviral interventions such as aerosolized ribavirin and new neuraminidase inhibitors remains to be defined in randomized trials.

Use of Oseltamivir to control influenza complications after bone marrow transplantation

Summary:Influenza infection can be severe in bone marrow transplant (BMT) recipients. Although yearly epidemics occur worldwide, and a higher risk of complication is expected in these patients, few studies have addressed the impact of the new neuraminidase inhibitors in the prognosis of influenza after BMT. Influenza A or B infections were found in 39 of the 66 patients (59%) showing a positive nasal wash by DFA. Influenza A was diagnosed in 18 patients and influenza B in 23 patients; two patients were infected by influenza A and B with 84- and 90-day intervals between episodes, respectively. Of the 41 episodes (61%) of influenza A or B, 25 infections occurred during the spring and summer months. Oseltamivir was introduced within 48 h of symptoms appearing. Only two patients (5.1%) developed influenza pneumonia, and no patient died of influenza. A total of 22 patients (56.4%) acquired influenza before day +180 when preventive vaccination strategies are precluded owing to poor immunogenicity of the vaccine during this period. Oseltamivir proved to be safe and appears to have played an important role in the outcome of influenza infection in this population. The therapeutic and/or prophylactic benefits of Oseltamivir in BMT recipients remain to be demonstrated in randomized, prospective trials.

The benefit of influenza vaccination after bone marrow transplantation

Summary:Influenza vaccine is recommended yearly for recipients after the sixth month of BMT. Although a higher risk of complications of influenza is expected to occur in BMT patients, no study has addressed the clinical efficacy of influenza vaccination in this setting. Focusing on the clinical benefits of influenza vaccination, we evaluated the risk factors for influenza infection in a cohort of 177 BMT recipients followed up for 1 year. Influenza was diagnosed in 39 patients. Multivariate analyses showed that seasonal exposure and more aggressive conditioning regimens were independently associated with increased risk for influenza. Influenza vaccination and steroid use showed a protective role. Of the 43 patients who had received BMT longer than 6 months, 19 were vaccinated (compliance rate= 44.2%) and vaccine efficacy was 80%. We conclude that influenza vaccination plays an important role in protecting BMT recipients against influenza and all efforts should be made to ensure good compliance with vaccination.

Influenza virus vaccination in kidney transplant recipients: serum antibody response to different immunosuppressive drugs

Salles MJC, Sens YAS, Boas LSV, Machado CM. Influenza virus vaccination in kidney transplant recipients: serum antibody response to different immunosuppressive drugs.
Clin Transplant 2010: 24: E17–E23.

Early measles vaccination in bone marrow transplant recipients

Summary:Measles vaccination has been recommended after the second year following bone marrow transplant (BMT) in patients not receiving immunosuppressive drugs. During a measles outbreak, we vaccinated all patients after the first year of transplant, and conducted a prospective trial to evaluate safety, effectiveness and sustained immunity after early vaccination. Patients received attenuated virus vaccine between 9 and 18 months after BMT. A total of 51 patients were evaluated and 27 of them (52.9%) were receiving immunosuppressive drugs. Only mild adverse reactions were noted. Nine patients (17.6%) were susceptible (IgG⩽100 mIU/ml) at vaccination, and all seroconverted. In those immune at vaccination, a four-fold increase in measles IgG titers was found in one of 34 patients (2.9%) with specific IgG⩾200 mIU/ml compared to 14 of 17 (82.3%) with IgG<200 mIU/ml (P< 0.0001). Sustained immunity after 24 months was more likely to occur in patients with specific IgG levels⩽200 or ⩾500 mIU/mL (83.4 and 100%, respectively) in comparison to patients with 200<IgG<499 mIU/ml at vaccination (50% P=0.017). We conclude that even though early measles vaccination is safe, few patients are susceptible on day +365 and this strategy should be reserved for epidemic situations posing significant threat for the patients.

Epidemiology of neglected tropical diseases in transplant recipients: review of the literature and experience of a Brazilian HSCT center

The rising success rate of solid organ (SOT) and haematopoietic stem cell transplantation (HSCT) and modern immunosuppression make transplants the first therapeutic option for many diseases affecting a considerable number of people worldwide. Consequently, developing countries have also grown their transplant programs and have started to face the impact of neglected tropical diseases (NTDs) in transplant recipients. We reviewed the literature data on the epidemiology of NTDs with greatest disease burden, which have affected transplant recipients in developing countries or may represent a threat to transplant recipients living in other regions. Tuberculosis, Leprosy, Chagas disease, Malaria, Leishmaniasis, Dengue, Yellow fever and Measles are the topics included in this review. In addition, we retrospectively revised the experience concerning the management of NTDs at the HSCT program of Amaral Carvalho Foundation, a public transplant program of the state of São Paulo, Brazil.

Community-acquired pneumonia in Chile: the clinical relevance in the detection of viruses and atypical bacteria

Background Adult community-acquired pneumonia (CAP) is a relevant worldwide cause of morbidity and mortality, however the aetiology often remains uncertain and the therapy is empirical. We applied conventional and molecular diagnostics to identify viruses and atypical bacteria associated with CAP in Chile. Methods We used sputum and blood cultures, IgG/IgM serology and molecular diagnostic techniques (PCR, reverse transcriptase PCR) for detection of classical and atypical bacteria (Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumoniae) and respiratory viruses (adenovirus, respiratory syncytial virus (RSV), human metapneumovirus, influenza virus, parainfluenzavirus, rhinovirus, coronavirus) in adults >18 years old presenting with CAP in Santiago from February 2005 to September 2007. Severity was qualified at admission by Fines pneumonia severity index. Results Overall detection in 356 enrolled adults were 92 (26%) cases of a single bacterial pathogen, 80 (22%) cases of a single viral pathogen, 60 (17%) cases with mixed bacterial and viral infection and 124 (35%) cases with no identified pathogen. Streptococcus pneumoniae and RSV were the most common bacterial and viral pathogens identified. Infectious agent detection by PCR provided greater sensitivity than conventional techniques. To our surprise, no relationship was observed between clinical severity and sole or coinfections. Conclusions The use of molecular diagnostics expanded the detection of viruses and atypical bacteria in adults with CAP, as unique or coinfections. Clinical severity and outcome were independent of the aetiological agents detected.

Frequency of human metapneumovirus infection in hematopoietic SCT recipients during 3 consecutive years

Respiratory viruses can cause significant morbidity in immunocompromised hosts. Human metapneumovirus (hMPV) has been increasingly associated with lower respiratory tract infection in hematopoietic SCT (HSCT) recipients, with mortality rates up to 50%. No data on the occurrence of hMPV infection in HSCT recipients have been reported in the southern hemisphere. We conducted a retrospective study including 228 nasal wash samples from 153 HSCT recipients with respiratory symptoms during 2001, 2002 and 2003. hMPV was detected by real-time PCR with primers complementary to the nucleocapsid region of hMPV genome. Eleven of the 153 patients (7.2%) acquired hMPV infection during the study period (6.4% in 2001, 4.7% in 2002 and 11.1% in 2003). Among the 11 HSCT recipients with hMPV infection, 1 died 8 days after the diagnosis, but the role of hMPV in the patients death could not be established. In 2001 and 2003, hMPV group A prevailed over group B. In 2002, both groups were detected equally. hMPV infections were diagnosed in late winter and spring. The frequency of hMPV infection in HSCT recipients living in Brazil was similar to those observed in the northern hemisphere. Sensitive techniques to detect hMPV should be included in the diagnostic assessment of HSCT recipients with respiratory symptoms.

Role of Neutralizing Antibodies in Adults With Community-Acquired Pneumonia by Respiratory Syncytial Virus

In a study of 356 adults with community-acquired pneumonia, respiratory syncytial virus was a frequent pathogen (13%). Serology and real-time reverse-transcription polymerase chain reaction improved the detection of repiratory syncytial virus. High respiratory syncytial virus serum-neutralizing antibody levels protected against severe pneumonia.

Extended antigenemia surveillance and late cytomegalovirus infection after allogeneic BMT.

Late CMV disease remains a major concern in allogeneic BMT recipients. Few surveillance data are available on the occurrence of CMV infection and recurrences after day +100. We evaluated the occurrence of antigenemia (AG) recurrences until day +365 in 76 patients who received pre-emptive ganciclovir (GCV) therapy prompted by AG ⩾2 positive cells. Sixty-two episodes of AG recurrences were detected in 33 of the 52 patients who had positive AG. Survival analysis showed a 45.4% probability of AG recurrence on day +100, 64.8% on day +180 and 71.2% on day +365. The median time for AG recurrences was 113 (35 to 343) days. Thirty-five of the 62 episodes (56.4%) occurred after day +100. More than 70% of the patients responded to a 2-week course of GCV and no CMV disease was observed shortly after discontinuation of GCV. The Cox proportional model showed a significant effect of AG recurrences on patients follow-up only when the patient developed chronic GVHD (P = 0.012). Extended surveillance favored early introduction of GCV and late CMV pneumonia occurred in only one of the 76 patients (1.3%). AG recurrences are frequent after day +100 and extended surveillance until day +365 is recommended for patients who develop chronic GvHD.Bone Marrow Transplantation (2001) 28, 1053–1059.