Biomedical subjects

Heli Piiparinen

Publications and source records attributed to Heli Piiparinen.

9 recordsLinked to original sources

PubMed2006

Monitoring of EBV-DNAemia by quantitative real-time PCR after adult liver transplantation.

BACKGROUND: Post-transplant lymphoproliferative disease (PTLD) causes significant morbidity and mortality in transplantation. The clinical significance of Epstein-Barr virus (EBV) in the development of PTLD is clear, but not all EBV-reactivations cause PTLD. OBJECTIVES: We retrospectively analyzed EBV-DNAemia in liver transplant patients by a quantitative TaqMan-based real-time plasma PCR. STUDY DESIGN: Altogether 1284 specimens, obtained from 105 patients for frequent monitoring of cytomegalovirus (CMV) and human herpesvirus-6 and -7 (HHV-6, HHV-7) during the post-transplant year, were retrospectively tested for EBV-DNA. RESULTS: Altogether, 14/105 (13%) patients showed EBV-DNAemia, which usually occurred within 3 months after transplantation and subsided within a few weeks. EBV-DNAemia occurred concurrently with CMV in 10/14, with HHV-6 in 11/14, and with all three betaherpesviruses in 4/14 cases. The peak viral loads were relatively low (median 2100 EBV-DNA copies/ml, range 568-6600), except in one patient who first had low-level EBV-DNA (562-3022 copies/ml) in the early post-transplant period, but on day 175 after transplantation developed high-level DNAemia (9851-86,975copies/ml) which continued for 6 months and developed into PTLD at 6 months after transplantation. CONCLUSION: Low-level EBV-DNAemia is common after liver transplantation, often occurring together with betaherpesviruses, but seldom leads to high viral loads or PTLD. However, monitoring of EBV-DNA levels in the patients can be useful.

Adult↗

PubMed2006

Multiplex-PCR and oligonucleotide microarray for detection of eight different herpesviruses from clinical specimens.

BACKGROUND: Human herpesviruses cause clinically important diseases, e.g. infections of the central nervous system. New diagnostic tools are required for rapid and reliable detection of these viruses. OBJECTIVES: A microarray-based method was designed for detection of eight human herpesviruses in cerebrospinal fluid (CSF), whole blood, plasma, serum and proficiency-testing specimens. STUDY DESIGN: Herpes simplex type 1 and 2, varicella-zoster, cytomegalo-, Epstein-Barr and human herpes viruses 6A, 6B and 7 were amplified from clinical specimens by two multiplex-PCRs and transcribed to single-stranded RNAs which were hybridized to oligonucleotides on microarray. The results were compared to those from conventional PCR. In total, 227 specimens were tested including 23 CSF, 10 whole blood, 73 plasma, 10 proficiency-testing samples and 111 negative control samples. RESULTS: Concordant results were obtained in 214/227 (94%). Microarray detected 10 possible double and one triple infection. Negative control samples (70 serum, 30 CSF and 11 proficiency-testing samples) were all negative. CONCLUSIONS: Microarray is suitable for detection of multiple herpesviruses in clinical samples.

Herpesviridae↗

PubMed2006

Quantitative TaqMan assay for the detection and monitoring of cytomegalovirus infection in organ transplant patients.

Quantitative polymerase chain reaction assays have become the most common methods in the determination of viral load during cytomegalovirus (CMV) infection of transplant patients. In recent years, the development of automated nucleic acid extraction devices together with the introduction of real-time technology have been important elements for improvements of these assays. This chapter describes a method for the quantitation of CMV DNA viral load in the plasma samples of organ transplant patients. The method is based on MagNA Pure LC nucleic acid extraction system (Roche) and the TaqMan real-time technology. MagNA Pure LC is highly automated procedure with which 32 plasma samples could be processed within 1.5 h. TaqMan chemistry and Sequence Detector System 7900HT device (Applied Biosystems) are used for the quantitative amplification of the CMV genome. The chapter also describes preparation of the plasmid, which is needed to achieve a quantitative standard curve for quantitation.

Cytomegalovirus↗

PubMed2005

Human herpesvirus-6 and -7 in pediatric stem cell transplantation.

BACKGROUND: Human herpesvirus-6 (HHV-6) and -7 (HHV-7) may reactivate with immunosuppression and cause symptoms varying from subclinical to severe organ manifestations. The presence of HHV-6 and -7 and their possible association with clinical problems among pediatric recipients of stem cell grafts was studied in a single institution setting between November 1999 and December 2001. PROCEDURE: A total of 60 patients, mean age 8.5 years, were transplanted: 2/3 received allogeneic grafts and 1/3 autologous stem cell rescue. The presence of HHV-6 and -7 was studied in blood by polymerase chain reaction (PCR) (HHV-6) and antigenemia (HHV-6 and -7). RESULTS: Both HHV-6 and -7 were frequently present in the blood of stem cell graft recipients. No significant difference in the incidence of HHV-6 or -7 reactivations between the allogeneic and autologous patients nor recipients of sibling or unrelated donor (URD) grafts was observed. HHV-6 antigenemia was associated with fever, rash, and delayed engraftment. Among symptomatic patients two cases of encephalitis were encountered with both having HHV-6 detectable in their cerebrospinal fluid (CSF) by PCR. CONCLUSIONS: HHV-6 and -7 seem to be common in blood both pre- and post-transplant among pediatric recipients of stem cell grafts. Prolonged reactivations appear to correlate with clinical symptoms such as fever, rash, and bone marrow suppression in the post-stem cell transplant setting (SCT), but severe complications are rare. Transient reactivations appear to be of very limited clinical significance.

Adolescent↗

PubMed2004

Facial nerve palsy after human herpesvirus 6 infection.

Facial nerve palsy has long been considered to have an infectious etiology, either viruses, mainly herpesviruses, or bacteria, such as Borrelia burgdorferi. We report for the first time the association of human herpesvirus 6 and facial palsy in a previously healthy 1-year 9-month-old boy who developed left facial nerve palsy 7 days after exanthema subitum caused by human herpesvirus 6.

Exanthema Subitum↗

PubMed2003

Varicella zoster and Borrelia burgdorferi are the main agents associated with facial paresis, especially in children.

BACKGROUND: The etiology of facial paresis (FP) often remains unresolved. Yet, a microbial association is frequently suspected. OBJECTIVE: To evaluate the infectious etiology of FP by using sensitive tests. STUDY DESIGN: We studied the serum and cerebrospinal fluid of 42 patients diagnosed with idiopathic peripheral facial paresis using sensitive serological methods and nucleic acid detection and for reference, 42 patients with other neurological disorders (OND) matched for age, sex, season and geographical area. RESULTS: Varicella zoster virus and Borrelia burgdorferi accounted for 56% of all associated agents in children with FP compared with 11% of OND (P=0.01). In adults, the respective numbers were 29 and 13%. Other treatable etiological agents, Chlamydia pneumoniae and Mycoplasma pneumoniae, accounted for 11% in children and 8% in adults and with the same prevalence between patients with FP and OND. CONCLUSIONS: Microbes, with specific therapy available accounted for 52% of all associated agents in the patients with FP when compared with 26% in controls with OND (P=0.04). Based on this, we conclude that the patients with FP may benefit from antimicrobial therapy.

Adolescent↗

PubMed2003

Lymphoproliferative disease after allogeneic stem cell transplantation--pre-emptive diagnosis by quantification of Epstein-Barr virus DNA in serum.

BACKGROUND: Lymphoproliferative disease (PTLD) is a life-threatening complication of organ transplantation. In matched, allogeneic, non-T-cell-depleted stem-cell transplantations (SCT) the disease develops early but has been thought to be rare. OBJECTIVES: We determined by strict histopathological criteria the incidence of fatal Epstein-Barr-virus (EBV)-related PTLD in a large number of SCT, and assessed the diagnostic value of a real-time quantitative polymerase chain reaction (qPCR) for EBV-DNA in serum specimens. STUDY DESIGN: Of the 257 SCT performed in Helsinki during 1994-1999, 132 (51%) recipients were alive and 125 (49%) had succumbed by June 2001. The necropsies were analyzed for EBV-related PTLD as evidenced by disseminated lymphocytic infiltrates labeled histochemically for antigens and RNA (EBER 1 and 2) detectable by in situ technology. From a subset of the PTLD cases (N=12) and a series of corresponding stem-cell recipient controls (N=36), consecutive samples of serum (N=103 and 364, respectively) were studied by qPCR for EBV-DNA, and the clinical data were reviewed. RESULTS: The post-mortem analysis revealed 18 cases of PTLD (14% of the deceased), all of whom had received intensive immunosuppressive treatment including anti-thymocyte globulin for treatment or prophylaxis of graft versus host disease (GVHD). By using qPCR all the PTLD patients became EBV-DNA positive, in progressively rising copy numbers. EBV-DNA was first detectable 70 (median; range 24-154) days after SCT or 23 (4-86) days before death; i.e. earlier than the symptoms which appeared 15 (2-85) days before death. Among the SCT controls, EBV-DNA occurred sporadically (in only 3.9% sera). CONCLUSIONS: qPCR for EBV-DNA in serum is a highly sensitive (100%) and specific (96%) diagnostic approach. Intensely immunosuppressed stem-cell recipients are at a great risk of developing PTLD, and should be carefully monitored for EBV-DNA, for pre-emptive treatment of this life-threatening disorder.

DNA, Viral↗

PubMed2002

Acute central nervous system complications in varicella zoster virus infections.

BACKGROUND: In a previous multicenter study on central nervous system (CNS) viral infections varicella zoster virus (VZV) appeared the most frequent etiologic agent and appeared often without rash. OBJECTIVE: To evaluate the appearance and diagnostics of VZV in CNS more thoroughly, we studied the cases systematically by using sensitive and specific methods to learn the best diagnostic approach in order to start specific therapy. STUDY DESIGN: We analyzed all serum and cerebrospinal fluid samples of 174 patients, 88 females and 86 males, with acute CNS symptoms associated with VZV infection diagnosed in the multicenter study on viral CNS infections. RESULTS: About 38 patients (22%) had chickenpox, 59 (34%) had shingles, and 77 (44%) had no cutaneous symptoms at all. The mean age of chickenpox patients was 8.6 years, of the others 46.6 and 41.4 years. VZV-specific nucleic acid was detected in the CSF in one fourth of the patients in all groups, primarily during the first week of illness. In serum specimens, specific IgM was present in two thirds of the patients with chickenpox, whereas in the others in one third of the cases. In CSF, specific IgM was present in 15-17% of patients with skin manifestations, compared with 6% of those without rash. CONCLUSIONS: The role of VZV infections in CNS complications seems remarkable, often presenting without rash. Even these cases should be promptly recognized in order to conduct proper antiviral therapy. In children, a combination of PCR and IgM tests is the best approach. In adults, PCR, together with the measurement of intrathecal antibody production yields best results.

Acute Disease↗

PubMed2002

Monitoring of viral load by quantitative plasma PCR during active cytomegalovirus infection of individual liver transplant patients.

A quantitative PCR test, the Cobas Amplicor CMV Monitor, was used for the monitoring of viral load in the peripheral blood of 27 individual liver transplant patients and correlated with cytomegalovirus (CMV) pp65 antigenemia. Altogether, 243 specimens were analyzed. During the first 3 months, 20 patients showed PCR positivity which correlated with pp65 antigenemia. Of those, 13 patients developed symptomatic CMV infection 27 to 52 days after transplantation, with a significantly higher peak viral load in PCR and in pp65 assay compared with the seven asymptomatic infections (median 10,200 versus 2,240 copies/ml, P < 0.05, and median 100 versus 30 pp65-positive cells/50,000 leukocytes, P < 0.01). Five were primary infections of D+/R- cases (donor CMV seropositive and recipient seronegative) and demonstrated, except in one case, a high peak viral load (>10,000 copies/ml; range, 10,200 to 21,600 copies, and > or =50 positive cells, range, 50 to 800 cells). The peak viral loads of the six D+/R+ patients with symptomatic infection varied widely (range, 2,290 to 126,000 copies and 50 to 300 positive cells). Two D-/R+ patients developed symptomatic infection with a lower viral load (range, 1,120 to 6,510 copies and 25 to 100 positive cells). All symptomatic infections were successfully treated with ganciclovir. The asymptomatic infections all in D+/R+ patients with low copy numbers (<5,500 copies) were monitored until CMV disappeared. One of the seven PCR-negative patients had one sample with low antigenemia, but the subsequent specimens were all negative. The time-related correlation of the two methods was also good. In summary, quantitative PCR could equally well be used as the CMV pp65 assay for the monitoring of viral load in individual transplant patients.

Adult↗