Pp65 antigenemia and cytomegalovirus diagnosis in patients with lupus nephritis: report of a series / Antigenemia pp65 e diagnóstico de citomegalovírus em pacientes com nefrite lúpica: série de casos

ABSTRACT Introduction: In contrast to organ transplantation, few studies correlate the monitoring of pp65 antigenemia with a diagnosis of cytomegalovirus (CMV) in patients with systemic lupus erythematosus (SLE). Objective: To highlight the importance of CMV outside transplantation, we monitored pp65 antigenemia in a series of SLE patients. Methods: From March 2015 to March 2016, SLE patients presenting kidney involvement, fever, and an unclear infection at hospital admission were monitored through pp65 antigenemia. The pp65 antigenemia assay, revealed by immunofluorescence, was correlated with clinical and laboratory findings. Results: We included 19 patients with a suspected unclear infection. A positivity for pp65 antigenemia was found in seven patients (36.8%). The mean age was 33.5 ± 11.2 years, 16 (84%) were females, and 16 (84%) were black. Lymphopenia, anemia, and higher scores of SLEDAI were significantly more common in pp65-positive patients. Five patients received antiviral therapy with ganciclovir. Although receiving specific CMV treatment, one patient died because of suspected CMV disease. Conclusions: Pp65 antigenemia might be relevant in SLE patients, and studies with a greater number of patients are needed in order to establish sensitivity and specificity of pp65 antigenemia in different clinical contexts of SLE patients.

RESUMO Introdução: Diferentemente do transplante de órgãos, poucos estudos correlacionam o monitoramento da antigenemia pp65 com o diagnóstico de citomegalovírus (CMV) em pacientes com lúpus eritematoso sistêmico (LES). Objetivo: De modo a destacar a importância do CMV para além do transplante, monitorizamos a antigenemia pp65 em uma série de pacientes com LES. Métodos: De março de 2015 a março de 2016, pacientes com LES que apresentaram acometimento renal, febre e infecção indeterminada na internação foram monitorados através da antigenemia pp65. O ensaio de antigenemia, revelada por imunofluorescência, foi correlacionado com achado clínicos e laboratoriais. Resultados: Foram incluídos 19 pacientes com suspeita de infecção indeterminada. Positividade para antigenemia pp65 foi encontrada em sete pacientes (36,8%). A idade média foi de 33,5 ± 11,2 anos; 16 (84%) eram do sexo feminino e 16 (84%) eram negros. Linfopenia, anemia e escore de SLEDAI mais elevado foram significativamente mais comuns em pacientes pp65 positivos. Cinco pacientes receberam terapia antiviral com ganciclovir. Apesar de receber tratamento específico para CMV, um paciente com suspeita de doença por CMV veio a óbito. Conclusões: Antigenemia pp65 pode ser relevante em pacientes com LES, e estudos com maior número de pacientes são necessários para estabelecer a sensibilidade e a especificidade da antigenemia pp65 em diferentes contextos clínicos envolvendo pacientes com LES.

Clinical correlates of pp65 antigenemia monitoring in the first months of post kidney transplant in patients undergoing universal prophylaxis or preemptive therapy

Abstract Introduction: Human cytomegalovirus is a major cause of morbidity in kidney transplant patients. Objectives: We aimed to study viral replication and serological response in the first months post kidney transplant in patients undergoing universal prophylaxis or preemptive therapy and correlate the findings with the clinical course of Human cytomegalovirus infection. Patients and methods: Independent from the clinical strategy adopted for managing Human cytomegalovirus infection, prophylaxis versus preemptive therapy, the pp65 antigenemia assay and serological response were assessed on the day of transplantation, and then weekly during the first three months of post-transplant. Results: From the 32 transplant recipients, 16 were positive for pp65 antigenemia, with a similar incidence rate in each group. There were no positive results in the first three weeks of monitoring; the positivity rate peaked at week eight. There was a trend for a higher and earlier frequency of positivity in the universal prophylaxis group in which the course of the Human cytomegalovirus infection was also more severe. Despite the differences in clinical picture and in the initial immunosuppressant schedule, the serological response was similar in both groups. Conclusion: Routine monitoring during the first three post-transplant months has a positive impact on the early detection of Human cytomegalovirus viral replication allowing for timely treatment in order to reduce morbidity of the disease. The strategy of universal therapy employing intravenous ganciclovir was associated to a worse clinical course of the Human cytomegalovirus infection suggesting that the use of >10 cells/2 × 105 leukocytes as a cut-off in this setting may be inappropriate.

Comparison of a rapid cytomegalovirus pp65 antigenemia assay revealed by immunofluorescence to an in-house assay revealed by immunoperoxidase for diagnosis in solid organ transplant recipient patients

Cytomegalovirus (CMV) antigenemia is still one of the two major assays available for diagnosis and monitoring of CMV infections. A commercial rapid test recently available in Brazil for quantification of human cytomegalovirus pp65 antigenemia revealed by immunofluorescence technique was compared with the original in-house method revealed by immunoperoxidase in patients receiving solid organ transplants. Of 80 blood samples tested for CMV antigenemia, 34 (42.5 percent) were positive: commercial assay detected 33 (97 percent) and in-house assay detected 20 (58.8 percent) samples. The numbers of positive cells in the two assays were different, with a median of 4.5 and 12 positive cells obtained by in-house and commercial kit, respectively. Discrepancies between assays occurred in 15 specimens from patients with low-grade antigenemia (median 6 positive cells). The assay-time was reduced in approximately 50 percent compared to in-house methodology. In conclusion, besides comparable results obtained for both assays, the commercial antigenemia assay provides more rapid and sensitive results.

Comparison of CMV pp65 antigen and IgM antibody detection for early recognition of CMV primary infection and reactivation.

Detection of Cytomegalovirus (CMV) pp65 antigen and CMV IgM antibody were compared for the early diagnosis of CMV primary infection or reactivation. Sixty seven immunocompromised patients were studied prospectively for the diagnosis of CMV primary infection or reactivation. CMV IgM antibody was detected in 19 (28.43%) of the 67 immunocompromised patients, whereas pp65 antigen was detected in 20 (29.8%). Among the 19 patients who were positive for both pp65 antigen and CMV IgM antibody, pp65 antigen was detected earlier in 10 of 19 patients. In the remaining 9 patients IgM antibody against CMV was detected simultaneously with the pp65 antigen. The pp65 antigen appeared on an average 16.37 days earlier than that of CMV IgM antibody.

Epidemiologia del síndrome urémco hemolítico en Argentina: diagnóstico del agente etiológico, reservorios y vías de transmissión / The epidemiology of hemolytic uremic syndrome in Argentina. Diagnosis of the etiologic agent, reservoirs and routes of transmission

Shiga toxin-producing Escherichia coli (STEC) cause sporadic cases and outbreaks of nonbloody and bloody diarrhea, and hemolytic uremic syndrome (HUS). E. coil O157:H7 is the most prevalent STEC serotype. However, other serotypes (O26:H11; O103:H2; O111:NM; O121:H19; O145:NM, among others) can cause a similar disease spectrum. Shiga toxins (Stx1, Stx2, and their variants), intimin, and enterohemolysin are the main virulence factors. Three different diagnostic criteria are used to determine the frequency of STEC infection: 1) isolation and characterization of STEC strains; 2) detection of specifically neutralizable free fecal Stx; and 3) Serological tests to detect Stx-antibodies. The surveillance of the STEC strains is performed using subtyping techniques: a) genotyping of Stx and eae by PCR-RFLP; b) phage typing of E. coil O157 strains; and c) pulsed-field gel electrophoresis. STEC O157 and non-O157 strains are recovered from clinic, animal, food and environmental samples, and E. coli O157:H7, a Stx2 and Stx2c producer, harboring eae and ehxA genes, is the most common serotype. During a prospective case-control study conducted to evaluate risk factors for sporadic STEC infection in Mendoza Province and Buenos Aires City and its surroundings during 2001-2002, exposures associated with risk included eating undercooked beef, contact with a child < 5 years with diarrhea and living in or visiting a place with farm animals. Both washing hands after handling raw beef, and eating fruits and vegetables were frequently protective. Strategies of prevention and control are necessary to decrease the incidence of STEC infections in Argentina.

Efectividad de la terapia anticipada con ganciclovir en receptores de trasplante renal de alto riesgo (R-/D+) para desarrollo de enfermedad por citomegalovirus / Effectiveness of preemptive therapy with ganciclovir in recipients of renal transplants at high risk (R-/D+) for the development of cytomegalovirus disease

Current management of renal transplant recipients who are CMV seronegative (R-) and receive an organ from a seropositive donor (D+) is controversial. These patients are at high risk for CMV disease and are usually treated with ganciclovir prophylaxis at variable dose and duration. An alternative to this approach is to administer ganciclovir only to those patients who are identified by virological markers to be at the highest risk to develop the disease (preemptive therapy). This prospective trial was conducted to asses the value of preemptive therapy to prevent CMV disease in R-/D+ kidney transplant recipients on triple drug immunosuppression without antilymphocyte induction. Sixteen adults receiving their first kidney transplant were enrolled and followed with pp65 antigenemia assay performed biweekly for the first 16 postransplant weeks, and then monthly to complete 12 months. Ganciclovir (5 mg/kg/day i.v., for 15 days) was administered as preemptive therapy upon detection of one or more antigen-positive cells per 150 x 10(3) peripheral blood leucocytes examined. For those receiving preemptive therapy, pp65 antigenemia was also repeated after completion of the regimen. CMV antigenemia was detected in 7/16 patients. At mean follow-up of 9 months (4-12 m) none of the 16 patients developed CMV disease. CMV serology (IgM) became positive in all patients after the first antigenemia result. The last follow-up mean serum creatinine (SCr) level was similar in both groups (1.35 mg/dL). In CMV R-/D+, the use of preemptive therapy guided by pp65 antigenemia is effective in preventing CMV disease. By using this strategy, 9 of 16 patients were spared ganciclovir prophylaxis with no effect on rejection or CMV disease. The clinical benefit and cost/effectiveness of this strategy should be evaluated against universal prophylaxis in these high-risk patients.