Dino Sgarabotto

Infection dynamics in a traveller with persistent shedding of Zika virus RNA in semen for six months after returning from Haiti to Italy, January 2016.

We describe the dynamics of Zika virus (ZIKV) infection in a man in his early 40s who developed fever and rash after returning from Haiti to Italy, in January 2016. Follow-up laboratory testing demonstrated detectable ZIKV RNA in plasma up to day 9 after symptom onset and in urine and saliva up to days 15 and 47, respectively. Notably, persistent shedding of ZIKV RNA was demonstrated in semen, still detectable at 181 days after onset.

Evaluation of Cytomegalovirus (CMV)-Specific T Cell Immune Reconstitution Revealed That Baseline Antiviral Immunity, Prophylaxis, or Preemptive Therapy but not Antithymocyte Globulin Treatment Contribute to CMV-Specific T Cell Reconstitution in Kidney Transplant Recipients

BACKGROUND The ultimate goal of organ transplantation is the reestablishment of organ function and the restoration of a solid immunity to prevent the assault of potentially deadly pathogens. T cell immunity is crucial in controlling cytomegalovirus (CMV) infection. It is still unknown how preexisting antiviral T cell levels, prophylaxis, or preemptive antiviral strategies and pharmacological conditioning affect immune reconstitution. METHODS Seventy preemptively treated CMV-seropositive recipients, 13 prophylaxis-treated CMV-seronegative recipients of seropositive donor transplants, 2 seropositive recipients of seronegative donor kidneys, and 27 pretransplant subjects were enrolled in a cross-sectional study and analyzed for CMV viremia (DNAemia) and CMV-specific T cell response (interferon-gamma enzyme-linked immunospot assay) before transplantation and at 30, 60, 90, 180, and 360 days after transplantation. RESULTS CMV-seropositive transplant recipients displayed a progressive but heterogeneous pattern of immune reconstitution starting from day 60 after transplantation. CMV-seronegative recipients did not mount a detectable T cell response throughout the prophylaxis regimen. A single episode of CMV viremia (CMV copy number, 7000-170,000 copies/mL) was sufficient to prime a protective T cell immune response in CMV-seronegative recipients. Antithymocyte globulin treatment did not significantly affect CMV-specific T cell response. CONCLUSIONS Baseline immunity, antiviral therapy but not antithymocyte globulin treatments profoundly influence T cell reconstitution in kidney transplant recipients.

Comparison of Cytomegalovirus (CMV) Enzyme-Linked Immunosorbent Spot and CMV Quantiferon Gamma Interferon-Releasing Assays in Assessing Risk of CMV Infection in Kidney Transplant Recipients

ABSTRACT Assessing cytomegalovirus (CMV)-specific cell-mediated immunity (CMI) represents an appealing strategy for identifying transplant recipients at risk of infection. In this study, we compared two gamma interferon-releasing assays (IGRAs), Quantiferon-CMV and CMV enzyme-linked immunosorbent spot (ELISPOT), to determine the ability of each test to predict protective CMV-specific T-cell responses. Two hundred twenty-one Quantiferon-CMV and ELISPOT tests were conducted on 120 adult kidney transplant recipients (KTRs), including 100 CMV-seropositive transplant recipients (R+) and 20 CMV-seronegative transplant recipients of a CMV-positive donor (D+/R−). As a control cohort, 39 healthy adult subjects (including 33 CMV-seropositive and 6 CMV-seronegative subjects) were enrolled. CMV IgG serology was used as a reference for both tests. In the CMV-seropositive individuals, the ELISPOT and Quantiferon-CMV assays provided 46% concordance with the serology, 12% discordance, 18% disagreement between ELISPOT or Quantiferon-CMV and the serology, and 24% gray areas when one or both tests resulted in weak positives. None of the CMV-seronegative subjects showed detectable responses in the ELISPOT or the Quantiferon-CMV test. In transplant recipients, both the ELISPOT and Quantiferon-CMV assays positively correlated with each other and negatively correlated with CMV DNAemia in a significant way (P < 0.05). During the antiviral prophylaxis, all 20 D+/R− KTRs we examined displayed undetectable Quantiferon-CMV and ELISPOT results, and there was no evidence of CMV seroconversion. The receiving operator curve (ROC) statistical analysis revealed similar specificities and sensitivities in predicting detectable viremia (areas under the curve [AUC], 0.66 and 0.62 for Quantiferon-CMV and ELISPOT, respectively). ELISPOT and Quantiferon-CMV values of >150 spots/200,000 peripheral blood mononuclear cells (PBMCs) and >1 to 6 IU gamma interferon (IFN-γ) were associated with protection from CMV infection (odds ratios [OR], 5 and 8.75, respectively). In transplant recipients, the two tests displayed similar abilities for predicting CMV infection. Both the ELISPOT and Quantiferon-CMV assays require several ameliorations to avoid false-negative results.

Human cytomegalovirus-specific T-cell immune reconstitution in preemptively treated heart transplant recipients identifies subjects at critical risk for infection.

ABSTRACT Human cytomegalovirus (CMV) infection represents a major threat for heart transplant recipients (HTXs). CMV-specific T cells effectively control virus infection, and thus, assessment of antiviral immune recovery may have clinical utility in identifying HTXs at risk of infection. In this study, 10 CMV-seropositive (R+) pretransplant patients and 48 preemptively treated R+ HTXs were examined before and after 100 days posttransplant. Preemptive treatment is supposed to favor the immune recovery. CMV DNAemia and gamma interferon enzyme-linked immunosorbent spot (ELISPOT) assay were employed to assess the viremia and immune reconstitution. HTXs could be categorized into three groups characterized by high (>100), medium (50 to 100), and low (<50) spot levels. Early-identified high responders efficiently controlled the infection and also maintained high immunity levels after 100 days after transplant. No episodes of grade ≥2R rejection occurred in the high responders. Midresponders were identified as a group with heterogeneous trends of immune reconstitution. Low responders were 41% and 21% of HTXs before and after 100 days posttransplant, respectively. Low responders were associated with a higher incidence of infection. The effect of viremia on immune recovery was investigated: a statistically significant inverse correlation between magnitude of viremia and immune recovery emerged; in particular, each 10-fold increase in viremia (>4 log10 DNAemia/ml) was associated with a 36% decrease of the ELISPOT assay spot levels. All episodes of high viremia (>4 log10 DNAemia/ml) occurred from 1 to 60 days after transplant. Thus, the concomitant evaluation of viremia and CMV immune reconstitution has clinical utility in identifying HTXs at risk of infection and may represent a helpful guide in making therapeutic choices.

Torque Teno virus: any pathological role in liver transplanted patients?

Few studies have been performed on the prevalence of Torque Teno Virus (TTV) infection in liver transplant (LT) recipients. The aim of this study was to assess the prevalence, viremia and genogroup pattern of TTV among LT patients and to ascertain whether TTV causes liver damage in liver transplanted patients with biochemical and histological changes of unknown origin. Twenty‐five patients were evaluated before and after LT; 80 healthy subjects were considered as controls. Serum samples were serially obtained from all the patients before LT and thereafter at 3, 6 and 12 months post‐transplant. Serum TTV‐DNA and genogroups were assessed by PCR. Patients underwent protocol serial liver biopsies at 6 and 12 months after LT. Results were compared using the Chi‐squared tests, McNemar’s and Student’s t‐tests. TTV‐DNA was found in 25/25 patients before LT and in 60/80 blood donors (P < 0.01). The TTV‐DNA load increased significantly after LT (P < 0.001). TTV‐DNA was significantly higher in patients on calcineurin inhibitors (CNI) and azathioprine or mycophenolate mofetil than in patients on CNI alone (P = 0.04) at 3 months after LT. Genogroup analysis showed a significant increase in genogroup 5 positivity after LT. No differences were seen in the viremia of patients compared according to their viral versus other etiologies of their liver disease before transplantation. Viremia and TTV genotype patterns did not correlate with the presence of hypertransaminasemia or histological liver damage of unknown etiology. The prevalence of TTV‐DNA was significantly higher in patients with liver cirrhosis than in controls and the viral load was significantly higher after LT than beforehand. On the basis of our data, TTV does not seem to cause liver damage following LT, although larger studies with a long‐term follow up are needed to confirm these findings.

Synercid plus vancomycin for the Treatment of Severe Methicillin-resistant Staphylococcus aureus and Coagulase-negative Staphylococci Infections: Evaluation of 5 Cases

Synercid (quinupristin/dalfopristin), the first semi-synthetic injectable streptogramin, is a promising alternative to glycopeptides against many Gram-positive multiresistant bacteria. Vancomycin is still considered an effective agent for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections but therapeutic failures with glycopeptides have been observed, even for the treatment of infections caused by S. aureus strains sensitive to vancomycin. Synercid, in combination with a glycopeptide, may address this problem without causing significant side effects due to the different toxicity patterns of the 2 antimicrobials. This study reports our experience with the combination of Synercid and vancomycin in 5 patients with severe infection caused by MRSA or methicillin-resistant coagulase-negative Staphylococcus.

Leuconostoc Species: A Case-cluster Hospital Infection

Leuconostoc species are members of the Streptococcacae family. They are generally regarded as non-pathogenic culture contaminants and are thought to be an uncommon cause of infection. We present a study of a case-cluster nosocomial infection due to Leuconostoc spp. Three patients were hospitalized at the time of the infection with significant underlying diseases and all had a compromised skin and mucous barriers. Two had received previous antibiotic therapy. This report highlights the importance of Leuconostoc spp. as an emerging pathogen, even though the modes of transmission and reservoirs of Leuconostoc spp. are as yet unknown.

Splenic Infarct During Infectious Mononucleosis

We present a case of splenic infarct during infectious mononucleosis in a 17-y-old boy. The patients condition improved without the need for surgery.We present a case of splenic infarct during infectious mononucleosis in a 17-y-old boy. The patients condition improved without the need for surgery.

Changes in the Mitogenic Activity of Platelet-Derived Growth Factor(s) in Patients with Myeloproliferative Disease

Platelet-derived growth factor (PDGF) is thought to take part in the genesis of bone marrow fibrosis that can be found in patients with myeloproliferative diseases. We evaluated platelet mitogenic activity as the difference between serum and plasma activity in 8 patients with myeloproliferative disease. We observed a trend of lower values in 2 cases of polycythemia vera and 2 cases of essential thrombocythemia, as seen by other authors. Two patients suffering from chronic myeloid leukemia were within the normal range. In contrast, our 2 cases of idiopathic myelofibrosis showed increased levels. If confirmed by further studies, this could suggest a pathogenetic relationship between increased levels of PDGF and bone marrow fibrosis, and give differential diagnostic significance to the PDGF mitogenic assay in myeloproliferative diseases.

Linezolid in the treatment of brain abscess due to peptostreptococcus

Brain abscesses can be caused by bacteria, fungi, and parasites. Among bacteria, anaerobic organisms include the Bacteroides species group, Fusobacterium, Peptostreptococcus, and Propionibacterium. In these cases, a 4-week course of parenteral penicillin/cefalosporin and metronidazole is the standard of treatment. We describe a case of brain abscess secondary to anaerobic infection with Peptostreptococcus, which was successfully treated with parenteral and oral linezolid after failure of standard therapy.