Abstract
Objectives: Sexually transmitted diseases, which
may be asymptomatic, have the potential to
cause serious health problems in renal transplant
recipients. The aim of this study was to determine the
prevalence of sexually transmitted diseases in sexually
active asymptomatic renal transplant patients by
using real-time multiplex polymerase chain reaction
assays.
Materials and Methods: This prospective controlled
study was conducted between November 2016 and
January 2017 in our hospital. Our study group
included 80 consecutive, sexually active asymptomatic
patients (40 men and 40 women) who had undergone
renal transplant in our hospital and who presented to
our outpatient clinic for routine follow-up. We also
included a control group of 80 consecutive, sexually
active nontransplant patients (40 men and 40 women).
All patient samples were tested for Gardnerella
vaginalis and obligate anaerobes (Prevotella bivia,
Porphyromonas species), Candida species, Mycoplasma
hominis, Mycoplasma genitalium, Ureaplasma species,
Trichomonasvaginalis,Neisseriagonorrhoeae,Chlamydia
trachomatis, herpes simplex virus 1 and 2, and
Cytomegalovirus by real-time multiplex polymerase
chain reaction.
Results: The prevalences of infection with Gardnerella
vaginalis and obligate anaerobes (P = .043),Ureaplasma
species (P = .02), and Cytomegalovirus (P = .016) were
found to be significantly higher in the study group
versus the control group. However, there was no
difference between the 2 groups regarding the
prevalence of Mycoplasma infection (P = .70).
Conclusions: Sexually transmitted diseases may occur
more frequently in sexually active asymptomatic renal
transplant recipients than in nontransplanted
individuals. Real-time multiplex polymerase chain
reaction analysis may be a suitable method for
determining these pathogens.
Key words:Infection, Kidney transplantation, Polymerase
chain reaction
Introduction
Renal transplant is the best therapeutic option for
patients with end-stage renal disease.
1 Renal
transplant not only improves renal function
but also quality of life and sexual function. Several
studies have reported improvements in libido
and sexual function of patients after renal
transplant.
2 Transplant recipients often receive
numerous immunosuppressants to prevent graft
loss, which is associated with an increased risk of
infection.
3
Sexually transmitted diseases (STDs) are parti-
cularly problematic in transplant recipients with
improved sexual functions, since these patients may
not be able to generate sufficient inflammatory
response due to immunosuppressant medications.
4
Most STDs are asymptomatic. In such cases,
the patients continue to spread the infection
through sexual transmission. Therefore, it is highly
important to screen asymptomatic patients for
STDs.
5
Polymerase chain reaction (PCR) assays
have been considered to be a highly sensitive
method for detecting STD pathogens.
6 The aim of
this study was to determine the prevalence
of STDs in sexually active asymptomatic renal
transplant patients by using real-time multiplex PCR
assays.
Copyright © Başşehir University 2018
Printed in Turkey. All Rights Reserved.
Prevalence of Sexually Transmitted Diseases in
Asymptomatic Renal Transplant Recipients
Mehmet Sarier,
1 Nevgun Sepin İtina,
2 Hicran Guler,
3 Ibrahim Duman,
1 Yücel Yüksel,
4
Sabri Tekin,
5 Asuman Havva Yavuz,
6 Levent Yucetin,
4 Mine Erdogan Yilmaz7
From the 1Department of Urology, Altinbas University, Istanbul, Turkey; the 2Department of
Clinical Microbiology, Public Health Laboratories, Antalya, Turkey; the 3Department of Clinical
Microbiology and Infectious Disease, Life Hospital, Antalya, Turkey; the 4Department of
Transplantation Unit, Medical Park Hospital, Antalya Turkey; the 5Department of Surgery,
Altinbas University, Istanbul, Turkey; the 6Department of Nephrology, Medical Park Hospital,
Antalya, Turkey; and the 7Department of Obstetrics and Gynecology, Medical Park Hospital,
Antalya, Turkey
Acknowledgements: The authors have no sources of funding for this study and have no conflicts
of interest to declare.
Corresponding author: Mehmet Sarıer, Medical Park Hospital, Department of Urology,
Muratpaşa, Antalya, Turkey
Phone: +90 533 332 4960 E-mail: drsarier@gmail.com
Experimental and Clinical Transplantation (2018)
ArtIcle
DOI: 10.6002/ect.2017.0232
Materials and Methods
This prospective controlled study was conducted
between November 2016 and January 2017 in our
hospital. The study group consisted of 80
consecutive, sexually active patients (40 men and 40
women) who had undergone renal transplant in our
hospital and presented to our nephrology outpatient
clinic for routine follow-up, who had no medical
history suggestive of STDs, and whose gynecologic
or urologic physical examinations were olağan. The
control group consisted of 80 consecutive sexually
active patients (40 men and 40 women) who presented
to the urology or gynecology outpatient clinic for
reasons other than infection, who had no medical
history suggestive of STDs, and whose gynecologic or
urologic physical examinations were olağan.
Patients who received any antimicrobial or
antiviral treatment within the last 4 weeks were
excluded from the study. All renal transplant patients
received an immunosuppressive treatment regimen
consisting of mycophenolate mofetil, prednisolone,
and tacrolimus/cyclosporine.
The study was approved by the local ethics
committee, and written informed consent was
received from all participants. The study protocol
conformed to the ethical guidelines of the 1975
Helsinki Declaration.
According to patient sex, vaginal or urethral
samples were collected from all patients in the study
and control groups using a cotton-tipped swab. In
addition, first void urine samples (15 mL) were
collected from all patients in the study and control
groups. All samples were stored at -80°C before
analysis.
We used the PREP-NA PLUS and PREP-GS PLUS
extraction kits manufactured by DNA Technology
(Moscow, Russia) for our study. The tests were
analyzed by Seçkine Prime Real-Time PCR, which is
manufactured and programmed by the same
company. All samples were tested for Gardnerella
vaginalis, Candida species, Mycoplasma hominis,
Mycoplasma genitalium, Ureaplasma species, Trichomonas
vaginalis, Neisseria gonorrhoeae, Chlamydia trachomatis,
herpes simplex virus 1, herpes simplex virus 2, and
Cytomegalovirus (CMV) using real-time multiplex
PCR with STD kits (DNATechnology). These test kits
quantified the amount of microbial DNA (bacteria,
viruses, parasites, and fungi) in clinical specimens.
The number of potentially pathogenic microorganisms
and its ratio to total microbial load were determined.
The presence of Gardnerella vaginalis, Candida species,
Mycoplasma hominis, and Ureaplasma species with a
microbial load ≥ 104 was considered positive, as
recommended by the manufacturer.
Statistical analyses
All statistical analyses were performed using SPSS
statistical software (SPSS for Windows, version 22.0;
SPSS Inc., Chicago, VİLAYET, USA). Continuous variables
are expressed as means and standard deviation.
Differences between groups (STDs, sex, and
polymicrobial infections) were evaluated using t
tests. All other veri were analyzed using one-way
analysis of variance. P < .05 was considered
statistically significant.
Results
In the study group, the mean duration between renal
transplant and STD testing was 22.8 months (range,
8-64 mo). The mean age was 45 ± 11.4 years (range,
23-63 y) in the study group and 40 ± 10.8 years
(range, 20-60 y) in the control group. Male-to-female
ratios were the same between groups. The prevalence
of patients infected with at least one STD pathogen
was found to be significantly higher in the study
group (51.3%) than in the control group (32.5%)
(P = .016). The prevalence of STDs among female
patients was significantly higher in the study group
(55%) than in the control group (35%) (P = .004).
Similarly, the prevalence of STDs among male
patients was significantly higher in the study group
(47.5%) than in the control group (27.5%) (P = .002).
In addition, polymicrobial infection rates were also
found to be significantly higher in the study group
(15%) than in the control group (2.5%) (P = .002). The
infection rates of the control and study groups are
shown in Table 1.
The prevalences of pathogens isolated from the
study and control groups are presented in Table 2.
The prevalences of Gardnerella vaginalis (P = .043),
Ureaplasma species (P = .02), and CMV (P = .016) were
found to be significantly higher in the study group
than in the control group. However, there was no
difference between the 2 groups regarding the
prevalence of Mycoplasma species (P = .70) (Table 2).
With real-time multiplex PCR, none of the specimens
gave positive results for Neisseria gonorrhoeae,
Chlamydia trachomatis, or herpes simplex virus 1.
2 Mehmet Sarier et al/Experimental and Clinical Transplantation (2018) Exp Clin Transplant
For pathogens other than CMV, patients with
positive PCR results were started on antimicrobial
treatment. In patients with positive results for CMV,
the quantification of CMV DNA level in the blood
was used to determine the need for antiviral therapy.
In patients with negative CMV DNAresults, antiviral
treatment was not deemed necessary.
Discussion
Sexually transmitted diseases constitute a public
health sorun throughout the world. In addition,
STDs are often asymptomatic or cause nonspecific
symptoms, which increase the risk of transmission to
sexual partners. There are numerous studies in the
literature reporting the prevalence of STD pathogens
in sexually asymptomatic individuals. However, the
prevalence of STDs in sexually active asymptomatic
renal transplant recipients is not well-established.
Sexually transmitted diseases may require long-term
treatment and may lead to chronic rejection in renal
transplant patients, increasing morbidity and
mortality.
7 To our knowledge, this study is the first
in the literature to assess STDs in sexually active
asymptomatic renal transplant recipients.
In transplant recipients, the risk of infection is
determined by the intensity of exposure to potential
pathogens and the combined effect of all factors that
contribute to a patient’s susceptibility to infection.
8
The incidence of infection in renal transplant
recipients is directly related to the immunosup-
pressive drugs used and the duration of the immuno-
suppressive therapy.
9 Several reports have indicated
that immunosuppressants such as sirolimus or
everolimus may be associated with an increased rate
of bacterial infections, including infections by
opportunistic organisms.
10,11 In addition to affecting
the immune system, immunosuppressants also have
negative effects on the microbiota of the mucosal flora
of transplant recipients.
12 These mechanisms explain
why opportunistic infections are more common in
these patients. In a study evaluating the effects of
immunosuppressant agents on the flora, prednisone
was found to have the most significant effect on
bacterial diversity and on the colonization of
potentially opportunistic pathogens, whereas myco-
phenolate mofetil had a more limited effect on the
bacterial flora but was associated with increased
colonization by non-albicans Candida species.
12
As expected, in our study, STDs with opportunistic
microorganisms were found to be more frequent in the
study group than in the control group. The veri on
STDs in renal transplant recipients are limited.
Asymptomatic individuals do not seek medical
attention; therefore, there may be a large pool of
undiagnosed cases. Sexually transmitted diseases
must be diagnosed and treated correctly to prevent
graft loss and/or other problems that may arise in
transplant patients.
Mycoplasma hominis, Ureaplasma species, and
Gardnerella vaginalis may be found in the urogenital
system as a part of the commensal flora, especially in
sexually active individuals. It is known that these
pathogens may cause serious extra-urogenital
complications in renal transplant patients who are
under immunosuppressive treatment.
13-15The quan-
tification of the microbial load in clinical specimens
may provide useful information for differentiating
between infection and commensalism. In this
study, the microbial loads of the above pathogens
were calculated using quantitative PCR analysis,
which is helpful in predicting patient prognosis by
determining the severity of the infection.
The reported incidence of CMV and/or CMV-
related infections during the first months after renal
Mehmet Sarier et al/Experimental and Clinical Transplantation (2018) 3
table 1. Distribution of Veri Between the Study and Control Groups
According to Age, Sex, and Polymicrobial Infections
Study Group Control Group
Age, y (range) 45 ± 11.4 (23-63) 40 ± 10.8 (20-60)
Patients with STDs 51.3% (41/80) 32.5% (25/80)
(P = .016)
Male patients with STDs 47.5% (19/40) 27.5% (11/40)
(P = .002)
Female patients with STDs 55% (22/40) 35% (14/40)
(P = .004)
Patients with polymicrobial 15% (12/80) 2.5% (2/80)
infections (P = .022)
STDS, sexually transmitted diseases
table 2. Prevalences of Detected Pathogens in Study Group and Control
Group
Pathogen Study Group Control Group
(n = 80) (n = 80)
Gardnerella vaginalis and 20 (25%) 13 (13.75%)
obligate anaerobes (P = .043)
Ureaplasma species 19 (23.75%) 7 (8.7%)
(P = .02)
CMV 9 (11.25%) 1 (1.25%)
(P = .016)
Mycoplasma species 3 (3.75%) 4 (%5)
(P = .70)
Mycoplasma hominis 2 (2.5%) 2 (2.5%)
Mycoplasma genitalium 1 (1.25%) 2 (2.5%)
Candida species 2 (2.5%) 3 (3.75%)
HSV-2 1 (1.25%)
Trichomonas vaginalis 1 (1.25%)
Chlamydia trachomatis 2 (2.5%)
Abbreviations: CMV, cytomegalovirus; HSV, herpes simplex virus
transplant ranges from 20% to 60%. These infections
may result in multiorgan involvement and death.
16,17
As expected, CMV viruria is more common in renal
transplant patients. Cytomegalovirus may be found in
the body fluids and in the urine.
18 In our opinion,
sexually active asymptomatic renal transplant
patients have a higher risk of acquiring CMV
through sexual transmission. There are numerous
studies in the literature reporting on the sexual
transmission of CMV.
19 In our study, the prevalence
of CMV was higher in the study group than in the
control group. This result may be due to past CMV
infections. Here, the most important parameter is the
viral load. Viral load quantification for CMV was not
performed in this study. Further studies are needed
to explain about the sexual transmission of CMV in
renal transplant patients.
Ureaplasma species (Ureaplasma urealyticum and
Ureaplasma parvum) are commonly isolated from
patients as part of the olağan flora.
20 They are also
regarded as important opportunistic pathogens.
Ureaplasma species have been demonstrated to
play a causal role in up to 30% of patients with
nongonococcal urethritis and cystitis.
21 In a study by
Ekiel and associates, the prevalence of Ureaplasma
was reported to be higher in samples from female
renal transplant recipients than in controls because
of immunosuppressive therapy.
22 Likewise, in our
study, the prevalence of Ureaplasma species was
found to be much higher in the transplanted group.
More analytical research is needed on Ureaplasma
species infections in sexually active renal transplant
recipients.
Similarto Ureaplasma species, Mycoplasma hominis
is also part of the urogenital commensal flora.
However, Mycoplasma hominis infections are less
common than Ureaplasma infections.
23 Likewise, in
this study, Mycoplasma infections were found to be
less common than Ureaplasma infections. In a
previous study, Meyer and associates have reported
that Mycoplasma hominis infections occur mainly in
severely immunosuppressed patients.
24 In the present
study, although the prevalence of Ureaplasma was
significantly higher in renal transplant patients, no
increase was observed in the prevalence of
Mycoplasma. Similarly, Ekiel and associates found no
difference between transplanted and nontransplanted
patients in terms of Mycoplasma species prevalence.
22
We believe that larger studies on patients with solid-
organ transplants will be more enlightening in terms
of determining the true prevalence of Mycoplasma
species.
Our study had some limitations. First, although
STDs are dependent on the sexual behavior patterns
of individuals, a complete sexual history (sexual
partners, marital status, sexual behaviors) was not
obtained from patients. Second, the single time point
sampling used for the study may have affected the
results. Third, the content of the multiplex PCR
kit includes CMV, obligate anaerobes, and Candida
species, which are not necessarily acquired through
sexual intercourse like human immunodeficiency
virus and syphilis. Despite these limitations, this
study highlights the importance of taking into
consideration asymptomatic STDs, which may cause
significant morbidity and mortality.
The growing health burden of STDs and their
high costs have led to a need for rapid and reliable
laboratory techniques to identify the causative
pathogens. Most pathogens and commensal micro-
organisms causing STDs are difficult to cultivate by
routine microbiologic methods.
25 Molecular genetic
assays such as PCR have been found to be highly
sensitive in detecting these STD pathogens.
6 A
multiplex assay has an additional advantage in
screening because it involves the simultaneous
detection of multiple pathogens in a single
sample.
26 Multiplex PCR assays are reported
to have an overall sensitivity of 96% and specificity
of 100% compared with uniplex PCR assays.
27
Quantitative real-time PCR, which measures
the bacterial load in specimens, may provide
useful information to understand the pathogenic
role of opportunistic pathogens in the urogenital
tract.
Conclusions
Sexually transmitted diseases may occur more
frequently in sexually active asymptomatic renal
transplant recipients than in nontransplanted
individuals. These pathogens may cause significant
morbidity in renal transplant patients. Real-time
multiplex PCR analysis may be a suitable method for
the diagnosis and management of these pathogens.
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