Spinello Antinori

Leishmaniasis among organ transplant recipients

Leishmaniasis is a rarely reported disease among transplant recipients; however, the number of published cases has quadrupled since the beginning of the 1990s. Most cases have been observed in patients living in countries of the Mediterranean basin. Leishmaniasis is most commonly associated with kidney transplantation (77%), and cases are also recorded among patients undergoing liver, heart, lung, pancreas, and bone marrow transplantation. Visceral leishmaniasis (VL) is the most frequently observed clinical presentation, followed by mucosal leishmaniasis and more rarely cutaneous leishmaniasis. Transplant recipients with VL develop the classic clinical form of the disease, which is a febrile hepatosplenic and pancytopenic syndrome. Immunodepression seems to predispose to development of mucosal leishmaniasis caused by viscerotropic strains. Early diagnosis of VL is crucial for patient therapy and outcome; however, this is frequently overlooked or delayed in transplant patients. Pentavalent antimonials are the most commom form of treatment for VL, but have a high incidence of toxicity (34%). Although used in fewer patients, liposomal amphotericin B seems to be better tolerated and should be considered as first-line therapy in transplant recipients.

Clinical Use of Polymerase Chain Reaction Performed on Peripheral Blood and Bone Marrow Samples for the Diagnosis and Monitoring of Visceral Leishmaniasis in HIV-Infected and HIV-Uninfected Patients : A Single-Center, 8-Year Experience in Italy and Review of the Literature

BACKGROUND To overcome some of the limitations of conventional microbiologic techniques, polymerase chain reaction (PCR)-based assays are proposed as useful tools for the diagnosis of visceral leishmaniasis. PATIENTS AND METHODS A comparative study using conventional microbiologic techniques (i.e., serologic testing, microscopic examination, and culture) and a Leishmania species-specific PCR assay, using peripheral blood and bone marrow aspirate samples as templates, was conducted during an 8-year period. The study cohort consisted of 594 Italian immunocompetent (adult and pediatric) and immunocompromised (adult) patients experiencing febrile syndromes associated with hematologic alterations and/or hepatosplenomegaly. Identification of the infecting protozoa at the species level was directly obtained by PCR of peripheral blood samples, followed by restriction fragment-length polymorphism analysis of the amplified products, and the results were compared with those of isoenzyme typing of Leishmania species strains from patients, which were isolated in vitro. RESULTS Sixty-eight patients (11.4%) had a confirmed diagnosis of visceral leishmaniasis. Eleven cases were observed in human immunodeficiency virus (HIV)-uninfected adults, 20 cases were observed in HIV-infected adults, and the remaining 37 cases were diagnosed in HIV-uninfected children. In the diagnosis of primary visceral leishmaniasis, the sensitivities of the Leishmania species-specific PCR were 95.7% for bone marrow aspirate samples and 98.5% for peripheral blood samples versus sensitivities of 76.2%, 85.5%, and 90.2% for bone marrow aspirate isolation, serologic testing, and microscopic examination of bone marrow biopsy specimens, respectively. None of 229 healthy blood donors or 25 patients with imported malaria who were used as negative control subjects had PCR results positive for Leishmania species in peripheral blood samples (i.e., specificity of Leishmania species-specific PCR, 100%). PCR and restriction fragment-length polymorphism analysis for Leishmania species identification revealed 100% concordance with isoenzyme typing in the 19 patients for whom the latter data were available. CONCLUSIONS PCR assay is a highly sensitive and specific tool for the diagnosis of visceral leishmaniasis in both immunocompetent and immunocompromised patients and can be reliably used for rapid parasite identification at the species level.

Discontinuation of Maintenance Therapy for Cryptococcal Meningitis in Patients with AIDS Treated with Highly Active Antiretroviral Therapy: An International Observational Study

We conducted a retrospective, multicenter study evaluating the safety of discontinuing maintenance therapy for cryptococcal meningitis after immune reconstitution. Inclusion criteria were a previous definitive diagnosis of cryptococcal meningitis, a CD4 cell count of >100 cells/microL while receiving highly active antiretroviral therapy (HAART), and the subsequent discontinuation of maintenance therapy for cryptococcal meningitis. The primary end point was relapse of cryptococcal disease. As of July 2002, 100 patients were enrolled. When maintenance therapy was discontinued, the median CD4 cell count was 259 cells/microL and the median plasma virus load was <2.30 log10 copies/mL, and serum cryptococcal antigen was undetectable in 56 patients. During a median follow-up period of 28.4 months (range, 6.7-64.5; 262 person-years), 4 events were observed (incidence, 1.53 events per 100 person-years; 95% confidence interval, 0.42-3.92). Three of these patients had a CD4 cell count of >100 cells/microL and a positive serum cryptococcal antigen test result during the recurrent episode. In conclusion, discontinuation of maintenance therapy for cryptococcal meningitis is safe if the CD4 cell count increases to >100 cells/microL while receiving HAART. Recurrent cryptococcal infection should be suspected in patients whose serum cryptococcal antigen test results revert back to positive after discontinuation of maintenance therapy.

Role of PCR in Diagnosis and Prognosis of Visceral Leishmaniasis in Patients Coinfected with Human Immunodeficiency Virus Type 1

ABSTRACT A group of 76 consecutive human immunodeficiency virus (HIV)-positive patients with fever of unknown origin (n = 52) or fever associated with pulmonary diseases was evaluated in order to assess the usefulness of PCR with peripheral blood in the diagnosis and follow-up of visceral leishmaniasis. We identified 10 cases of visceral leishmaniasis among the 52 patients with fever of unknown origin. At the time of diagnosis, all were parasitemic by PCR with peripheral blood. During follow-up, a progressive decline in parasitemia was observed under therapy, and all patients became PCR negative after a median of 5 weeks (range, 6 to 21 weeks). However, in eight of nine patients monitored for a median period of 88 weeks (range, 33 to 110 weeks), visceral leishmaniasis relapsed, with positive results by PCR with peripheral blood reappearing 1 to 2 weeks before the clinical onset of disease. Eight Leishmania infantum and two Leishmania donovani infections were identified by PCR-restriction fragment length polymorphism analysis. PCR with peripheral blood is a reliable method for diagnosis of visceral leishmaniasis in HIV-infected patients. During follow-up, it substantially reduces the need for traditional invasive tests to assess parasitological response, while a positive PCR result is predictive of clinical relapse.

Antibiotic Usage and Risk of Colonization and Infection with Antibiotic-Resistant Bacteria: a Hospital Population-Based Study

ABSTRACT Accurate assessment of risk factors for nosocomial acquisition of colonization by antibiotic-resistant bacteria (ARB) is often confounded by scarce data on antibiotic use. A 12-month, nested, multicenter cohort study was conducted. Target ARB were methicillin (meticillin)-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and ciprofloxacin-resistant Pseudomonas aeruginosa (CR-PA). Nares and rectal swabs were obtained before and after starting antibiotics. Pulsed-field gel electrophoresis was done to define genetic relatedness of the strains. Primary outcomes were (i) the mean time, in days, for acquisition of target ARB colonization in patients previously not colonized; (ii) the rate of acquisition per 1,000 antibiotic-days according to different classes of antibiotics; (iii) the rate of infection caused by the same bacteria as those previously isolated in screening samples; and (iv) the risk factors for ARB acquisition. In total, 6,245 swabs from 864 inpatients were processed. The rate of acquisition was 3%, 2%, and 1% for MRSA, VRE, and CR-PA, respectively. The rate of acquisition of ARB per 1,000 antibiotic-days was 14 for carbapenems, 9 for glycopeptides, and 6 for broad-spectrum cephalosporins and quinolones. The highest rates of acquisition were observed for carbapenems in dialyzed and diabetic patients. Four risk factors were independently associated with acquisition of target ARB: use of carbapenems, age of >70 years, hospitalization for >16 days, and human immunodeficiency virus infection. During the 30-day follow-up, 4 among 42 patients newly colonized by ARB (9%) suffered from an infection due to the same bacteria as those isolated in a previous screening sample. Colonizing and infecting strains from single patients were genotypically identical. Identifying ARB colonization early during antibiotic therapy could target a high-risk hospitalized population that may benefit from intervention to decrease the risk of subsequent nosocomial infections.

Leishmaniasis: new insights from an old and neglected disease

Leishmaniases are a clinically heterogeneous group of diseases caused by protozoa of the genus Leishmania. There is growing evidence that the true incidence of the disease is underestimated, especially in hyperendemic regions. Moreover, climate changes together with the increasing movement of humans and animals raise concerns about the possible introduction of Leishmania infection in previously spared areas. The disease is emerging in immunocompromised patients undergoing bone marrow or solid organ transplantation or treatment with biologic drugs. Furthermore, the deployment of military troops and travel to endemic areas are associated with the observation of a growing number of patients with cutaneous disease. Improvement in diagnostic methods, both in the field and in specialized laboratories, has been obtained through the implementation of molecular amplification methods and using the rK39 antigen as the substrate. Finally, new therapeutic approaches are gaining attention, such as the use of miltefosine for cutaneous leishmaniasis and paromomycin for visceral leishmaniasis, as well as the use of various antileishmanial drugs in combination.

Histoplasmosis among human immunodeficiency virus-infected people in Europe : Report of 4 cases and review of the literature

Abstract: We reviewed the clinical, microbiologic, and outcome characteristics of 72 patients with human immunodeficiency virus (HIV)-associated histoplasmosis (4 newly described) reported in Europe over 20 years (1984-2004). Seven cases (9.7%) were acquired in Europe (autochthonous), whereas the majority involved a history of travel or arrival from endemic areas. The diagnosis of progressive disseminated histoplasmosis (PDH) was made during life in 63 patients (87.5%) and was the acquired immunodeficiency syndrome (AIDS)-presenting illness in 44 (61.1%). Disease was widespread in 66 patients (91.7%) and localized in 6 (8.3%), with the skin being the most frequent site of localized infection. Overall skin involvement was reported in 47.2% of the patients regardless of whether histoplasmosis was acquired in Africa or South America. Reticulonodular or diffuse interstial infiltrates occurred in 52.8%. The diagnosis was made during life by histopathology plus culture in 44 patients (69.8%), histopathology alone in 18 (28.5%), and culture alone in 1 (1.5%). During the induction phase amphotericin B and itraconazole (74.6%) were the single most frequently used drugs. Both drugs were also used either in combination (10.2%) or in sequential therapy (11.8%). Cumulative mortality rate during the induction phase of treatment was 15.2%. Overall, 37 patients died (57.8%); death occurred early in the course in 18 (28.1%). Seven of 40 patients (17.5%) who responded to therapy subsequently relapsed. Autopsy data in 13 patients confirmed the widespread disseminated nature of histoplasmosis (85%) among AIDS patients with a median of 4.5 organs involved. The results of the present report highlight the need to consider the diagnosis of PDH among patients with AIDS in Europe presenting with a febrile illness who have traveled to or who originated from an endemic area. Abbreviations: AIDS = acquired immunodeficiency syndrome; CMV = cytomegalovirus, Hcc = H. capsulatum var. capsulatum; Hcd = H. capsulatum var. duboisii; HIV = human immunodeficiency virus; PCP = Pneumocystis pneumonia; PCR = polymerase chain reaction; PDH = progressive disseminated histoplasmosis; PR = present report.

AIDS-defining diseases in 250 HIV-infected patients; a comparative study of clinical and autopsy diagnoses

ObjectiveTo evaluate the correlation between clinical and autopsy findings in 250 AIDS patients. MethodsClinical and autopsy diagnoses of AIDS-defining diseases in 250 AIDS patients who died in Milan between May 1984 and February 1991 were compared. ResultsPneumocystis carinii (PCP) and oesophageal candidiasis were the most frequent clinical diagnoses, while cytomegalovirus (CMV) infection was observed in almost half of the autopsies. Forty-seven per cent of the diseases found at autopsy had not been diagnosed during life; CMV infection, mycoses, HIV-specific brain lesions, cerebral lymphomas and progressive multifocal leukoencephalopathy (PML) had a higher rate of non-diagnosis in life. CMV visceral infection accounted for the majority of the diseases not recognized in life. In contrast, clinically diagnosed PCP, oesophageal candidiasis and, to a lesser degree, brain toxoplasmosis were often not found at autopsy, possibly indicating a significant rate of recovery and prevention of relapse. Finally, bacterial pneumonia and sepsis, although not AIDS indicator diseases, were observed in approximately one-third of the autopsies. ConclusionConsiderable differences in the frequency and type of the AIDS-defining diseases diagnosed during life and at post mortem were found.

A third genotype of the human parvovirus PARV4 in sub-Saharan Africa.

PARV4 is a recently discovered human parvovirus widely distributed in injecting drug users in the USA and Europe, particularly in those co-infected with human immunodeficiency virus (HIV). Like parvovirus B19, PARV4 persists in previously exposed individuals. In bone marrow and lymphoid tissue, PARV4 sequences were detected in two sub-Saharan African study subjects with AIDS but without a reported history of parenteral exposure and who were uninfected with hepatitis C virus. PARV4 variants infecting these subjects were phylogenetically distinct from genotypes 1 and 2 (formerly PARV5) that were reported previously. Analysis of near-complete genome sequences demonstrated that they should be classified as a third (equidistant) PARV4 genotype. The availability of a further near-complete genome sequence of this novel genotype facilitated identification of conserved novel open reading frames embedded in the ORF2 coding sequence; one encoded a putative protein with identifiable homology to SAT proteins of members of the genus Parvovirus.

The Role of Cryptococcal Antigen Assay in Diagnosis and Monitoring of Cryptococcal Meningitis

In a recent paper evaluating the significance of cryptococcal antigen test results for 29 Chinese human immunodeficiency virus (HIV)-negative patients affected by cryptococcal meningitis, Lu and colleagues (8) showed in all patients a decrease of antigen titer from the baseline following antifungal therapy and suggested that a decrease can be used to monitor antifungal therapy efficacy but cannot be used as an index of cure. We have reviewed our experience with 66 HIV-positive patients out of 118 with cryptococcal meningitis for whom at least three serial determinations (at baseline, day 7, and day 14) of cryptococcal antigen tests on cerebrospinal fluid (CSF) were available (1). A total of 440 determinations (range, 3 to 28 antigen determinations; median, 5 antigen determinations) were available, and for 55 patients the last determination was considered (median, 13 weeks; range, 2 to 84 weeks). In Fig. ​Fig.11 is depicted the kinetics of CSF cryptococcal antigen together with the results of CSF culture. Overall, 53 patients (80%) showed a decrease of CSF antigen titer from the baseline (7 of whom had negative results), as follows: 27 cases of 1 to 3 dilutions, 16 cases of 4 to 6 dilutions, and 10 cases of 7 or more dilutions. However, 13 out of 15 of these patients for whom postmortem examination was available, despite evidence of several intravitam negative CSF cultures, still had cryptococcal meningitis or disseminated disease at autopsy (demonstrated by histopathology). Eight patients had an increase in the CSF antigen titer (four of 1 to 3 dilutions and four of 4 to 8 dilutions), and five showed stable (i.e., the same value) results throughout the follow-up. All the patients but two with an increase of CSF antigen titer had persistent positive CSF culture and died; four underwent autopsy showing disseminated cryptococcosis. FIG. 1. Change over time of CSF cryptococcal antigen titers and correlation with CSF cryptococcal cultures in 66 HIV-positive patients. Data of CSF antigen are median values. Data regarding CSF cultures refers to the total number of patients (n = 66), ... Our experience regarding the role of cryptococcal antigen to monitor antifungal therapy in AIDS patients is in keeping with that previously reported by Powderly et al. (11), who showed the lack of any correlation of changes of CSF or serum cryptococcal antigen and the outcome of cryptococcal meningitis. However, a high CSF antigen level has been identified as a sign of poor prognosis in patients with AIDS (1, 7); interestingly, more recently Thay cohorts of HIV-positive patients with cryptococcal meningitis showed a significant positive correlation between CSF cryptococcal colony-forming units (CFU) and CSF cryptococcal antigen titers at baseline (P < 0.0001), but the rapid rate of decline in CSF CFU was not correlated with that in CSF cryptococcal antigen titers (2). As shown in Table ​Table1,1, regardless of the different hosts in whom cryptococcal meningitis is diagnosed, among all methods employed the cryptococcal CSF antigen had the best overall sensitivity (94.1%) followed by the serum antigen (93.6%). However, some differences were observed in the different categories of hosts, with lower sensitivity in AIDS and immunocompetent patients (92%) and higher sensitivity among the other immunocompromised hosts without HIV infection. Persistently elevated CSF cryptococcal antigen in HIV-infected patients carries a poor prognosis and indicates ongoing production of viable Cryptococcus neoformans in tissue. In conclusion, CSF cryptococcal antigen seems to be the best test for diagnosis of cryptococcal meningitis in terms of sensitivity, but it is an unreliable tool, at least among HIV-positive patients, to drive therapeutic monitoring, particularly in assessing the point of discontinuation of antifungal therapy in HIV-infected patients. TABLE 1. Efficiency of different techniques in the diagnosis of cryptococcal meningitis in different hostsa