Materials and Methods
Study design
Cross-sectional study developed at
Department of Obstetrics and
Gynecology of the School of Medical Sciences, University of Campinas -
UNICAMP. This study was approved by the Ethics Committee of the
institution under number CAAE 06124512,6,2001,5404. Participants were
recruited at the institution’s Endocrinology Gynecology Outpatient
Clinic, a tertiary center. This study is a descriptive analysis of the
population studied in a larger study comprising a clinical trial with
interventions REBEC number RBR-74zbms.
Participants
We included 40 women with POI
diagnoses who had been using oral systemic HT for at least 6 months. POI
diagnosis was based on
hypergonadotrophic amenorrhea with at least two FSH dosages greater than
25 IU/mL (1). All participants signed an Informed Consent Term. Women
who had a specific acute infectious process involving vulvovaginitis or
ulcers in the genital region, or who had used medications related to
mucositis (long-term antibiotics, immunomodulators, chemotherapeutics),
and women with systemic or localized allergic conditions, were excluded.
Methodology
All women included in the study
collected vaginal secretion with a swab (Eswab Liquid-based Multipurpose
Collection and Transport System). The collected samples were vigorously
shaken and centrifuged at 800g for 10 minutes and the pellets obtained
were submitted to DNA extraction
using the MiSeq Reagent Kit
(600-cycle), Illumina Brasil Produtos de Biotecnologia Ltda, São Paulo,
Brazil, according to the recommended protocol by the manufacturer for
DNA extraction from bacteria. The samples were stored as DNA in a
biorepository in specific freezers (Freezers at -20○C) and used only for this purpose in the specialized clinical
laboratory. After thawing, the obtained DNA
were quantified and evaluated for
purity and quality and were submitted to the technique of Pirsequencing
16S rRNA gene amplicons in the Laboratory of Insulin Resistance of the
School of Medical Sciences of the University of Campinas - UNICAMP.
To carry out the 16S rRNA extraction through pyrosequencing, the 16S
library preparation protocol was performed. The samples, after reaching
room temperature, were submitted to the first stage of PCR (Polymerase
Chain Reaction) and then PCR cleaning through the reagents Ampure XP
Beads, EtOH 80% fresh, RSB and then placed in PCR postplates. The
second PCR stage was performed and the post-PCR cleaning procedure was
repeated with the same reagents. Data was then placed into the
quantification and normalization library and sequentially in the MiSeq
denaturing and loading library of samples. The entire methodology
followed the KIT protocol (MiSeq Reagent Kit (600-cycle), Illumina
Brasil Produtos de Biotecnologia LTDA, São Paulo, Brazil).
The data of the microbiome,
obtained from the pyrosequencing,
were sent for analysis to the
Scylla bioinformatics service, Campinas, Brazil,
for organization and phylogenetic
classification to divide the groups according to the cited
classification in literature by Ravel (4) as follows: Roman numerals
indicate five groups of bacterial vaginal communities. Groups of
communities I, II, III and V have as predominant bacterial Lactobacillus
crispatus, L. gasseri, L. iners and L. Jensenii, respectively, while
group IV contains a diversity of strict or facultative anaerobic
bacteria (Prevotella, Dialister, Atopobium, Gardnerella, Megasphaera,
Peptoniphilus, Sneathia, Eggerthella, Aerococcus, Finegoldia, and
Mobiluncus).
Ravel et al., in a study with healthy young women at reproductive age
revealed that in this population, group I communities, which occurred in
26.2%, were dominated by L. crispatus, while groups II (6.3%) , III
(34.1%) and V (5.3%) were dominated by L. gasseri, L iners and L.
jensenii, respectively (12).
Sample Size Calculation
This descriptive study is a secondary analysis of a clinical trial. The
sample size was calculated based on the main objective, which was
calculated in 30 patients, divided into two treatment groups. However,
in view of possible loss of follow-up, it was decided to include 40
women with POI. The current study represents a descriptive analysis of
the vaginal microbiome of the women at the inclusion time of the study.
Data Analysis
To describe the profile of the sample, tables with absolute frequency
(n) and percentage (%) values and descriptive statistics of the
numerical variables with mean values, standard deviation were made. To
classify the samples into their phylogenetic groups according to Ravel,
tables were also made with absolute (n) and percentage (%) frequency
values. For statistical analysis SAS software was used for Windows
version 9.2.