Could the CCR5-Delta32 mutation be protective in SARS-CoV-2 infection?

Increasing evidence points to host genetics as a factor in COVID-19 prevalence and outcome. CCR5 is a receptor for proinflammatory chemokines that are involved in host responses, especially to viruses. The CCR5-delta32 minor allele is an interesting variant, given the role of CCR5 in some viral infections, particularly HIV-1. Recent studies of the impact of CCR5-delta32 on COVID-19 risk and severity have yielded contradictory results. This ecologic study shows that the CCR5-delta32 allelic frequency in a European population was significantly negatively correlated with the number of COVID-19 cases (p=0.035) and deaths (p=0.006) during the second pandemic wave. These results suggest that CCR5-delta32 may be protective against SARS-CoV-2 infection, as it is against HIV infection, and could be predictive of COVID-19 risk and severity. Further studies based on samples from populations of different genetic backgrounds are needed to validate these statistically obtained findings.

A critical update on endothelial nitric oxide synthase gene variations in women with idiopathic recurrent spontaneous abortion: genetic association study, systematic review and meta-analyses.

A number of case-control studies investigated the association between idiopathic recurrent spontaneous abortion (IRSA) and variations in the gene encoding endothelial nitric oxide synthase (NOS3), but yielded contradictory results. Our aim was to test the association of the NOS3 variable number of tandem repeats (VNTR) in intron 4 and +894 G/T single-nucleotide polymorphism (SNP) with IRSA in Slovenian women (148 IRSA and 149 control women), conduct a systematic review of literature on the association between NOS3 gene variations and IRSA, and perform meta-analyses of studies that met the inclusion criteria, defined by virtue of the European Society for Human Reproduction and Embryology evidence-based guidelines for recurrent spontaneous abortion. Genotyping was performed using PCR and restriction fragment length polymorphism methods. The systematic review of literature (English language) was conducted using PubMed and Scopus databases, to 1 November 2014. We determined no association of IRSA with the VNTR in intron 4 and +894 G/T SNP in Slovenian women. Furthermore, 16 case-control studies were identified on the association between 15 NOS3 gene variations and IRSA. However, significant inconsistencies exist in the selection criteria of patients and controls between studies. The meta-analysis of VNTR in intron 4 was performed on five studies (894 patients, 944 controls), whereas the meta-analysis of +894 G/T SNP included six studies (1111 patients, 1121 controls). The association with IRSA was significant for the +894 G/T SNP under the dominant genetic model (GT+TT versus GG) based on fixed (odds ratio (OR) = 1.54, 95% confidence interval (CI) = 1.28-1.86, P = <0.01) and random effects models (OR = 1.54, 95% CI = 1.03-2.31, P = 0.03). In conclusion, the GT and TT genotypes of the +894 G/T SNP in women might contribute to a predisposition to IRSA. Additional genetic association and functional studies in different populations with larger numbers of participants and a uniformly defined IRSA are needed to clarify the contribution of NOS3 +894 G/T gene variation to IRSA.

CTLA-4 +49 A/G gene polymorphism in Croatian and Slovenian multiple sclerosis patients.

Polymorphisms in the CTLA-4 gene are known to be important in several autoimmune diseases, including multiple sclerosis (MS). Previous studies on the impact of CTLA-4 +49 A/G gene polymorphism have given contradictory results. We investigated the possible influence of this polymorphism on MS susceptibility and disease behaviour in Croatian and Slovenian populations. Genotyping was performed in 367 patients with MS and 480 control subjects using PCR-RFLP method. The G allele was present in 216 (58.9%) patients with MS vs. 282 (58.7%) healthy controls (P = 0.975, OR = 1.01, 95% CI = 0.76-1.32). No significant differences were observed in CTLA-4 +49 A or G allele distribution between patients and controls, indicating that this polymorphism does not influence susceptibility to MS in the surveyed populations. No correlation was observed between G allele carrier status and age at disease onset, disease course or severity.

A case of lichen ruber planus in a patient with familial multiple sclerosis.

Multiple sclerosis and lichen ruber planus are clinically and histologically distinct complex disorders of putative autoimmune aetiology that are fairly commonly observed in isolation but rarely found in combination. Only two previous reports have described lichen skin disorders in association with multiple sclerosis. The present report describes the case of a 51-year-old Caucasian woman exhibiting both familial multiple sclerosis and lichen ruber planus. This combination may have occurred by chance or it might imply that these disorders share common mechanisms in their pathogenesis.

Severe psychomotor retardation in a boy with a small supernumerary marker chromosome 19p.

We describe the clinical case of a nine-year-old boy with psychomotor retardation and a small supernumerary marker chromosome (sSMC) present in mosaic form. Fluorescence in situ hybridization (FISH) using centromere cross-hybridizing probes D1/5/19Z (pZ5.1), the whole chromosome paint probe 19, pool YACs19p (839B1, 872G3, 728C8), and pool YACs19q (767C4, 761C1, 786G6) demonstrated that the sSMC was derived from chromosome 19p. Based on GTG-banding and FISH analyses, the patient's karyotype was interpreted as: 47,XY,+mar.ish der(19) (:p13.3-->p11:)(839B1+, 872G3+,728C8+, D1/5/19Z+) de novo[52]/46,XY[48]. To our knowledge, only two other similar cases have been reported. This case helps to better delineate karyotype-phenotype correlations between sSMC 19p and associated clinical phenomena.

BanI polymorphism of cytosolic phospholipase A2 gene is associated with age at onset in male patients with schizophrenia and schizoaffective disorder.

The enzymes phospholipases A2 are believed to be involved in the pathology of schizophrenia. We investigated allelic and genotype frequencies of PLA2G4A BanI polymorphism and the rs4375 in PLA2G6A in Croatian schizophrenic patients (n=81) and controls (n=182), using PCR/RFLP. Genotype and allelic frequencies of both loci, alone or in combination did not show significant difference (chi2-test). Allele-wise and genotype-wise meta-analyses of BanI polymorphism in case-control and family-based studies also revealed no significant association with schizophrenia. Multiple logistic regression analyses revealed statistically significant association between several items from PANSS general psychopathology scale and BanI polymorphism in PLA2G4A. BanI polymorphism further showed a significant impact on mean age of the onset of disease in males (betaA1=0.351, P=0.021; Spearman's rA1=0.391, P=0.010) indicating lower mean age at admission in homozygous A2A2 males.

Angiotensin-converting enzyme I/D gene polymorphism and risk of multiple sclerosis.

OBJECTIVES: Angiotensin-converting enzyme (ACE) activity is increased in blood and cerebrospinal fluid of patients with multiple sclerosis (MS). In addition, in experimental autoimmune encephalomyelitis (EAE), an animal model of MS, the blockade of ACE suppresses the disease itself. To analyze the genetic association of the ACE gene with MS, we examined ACE gene insertion/deletion (I/D) polymorphism in MS patients. MATERIALS AND METHODS: A total of 313 MS patients from Slovenia and Croatia and 376 healthy controls were genotyped by polymerase chain reaction method. RESULTS: We found statistically significant differences in the distribution of ACE I/D allele frequencies (P < 0.01) and genotypes (P < 0.04) in male patients. ACE DD genotype was associated with MS in men at an odds ratio of 1.86 (95% CI 1.09-3.19, P = 0.02). CONCLUSIONS: DD genotype of ACE gene might contribute to a higher risk of developing MS in men.

HLA class I and class II polymorphism in the population of Rijeka, Croatia.

The aim of the study was to examine frequencies of HLA-A, -B, -DR antigens and haplotypes in population of Rijeka and to compare them with general Croatian and European populations. The subjects were 117 unrelated healthy blood donors. The antigens with the highest frequencies were: A2 (27.2%), A9 (16.3%), B5 (14.8%), B12 (11.8%), B18 (11.8%), DR5 (21.6%) and DR6 (13.8%). Comparison of HLA antigens frequencies has shown statistically significant difference in 1 antigen with Croatian population and in 8 antigens with European population. The HLA haplotypes with high frequencies included HLA-A2, B5 (6.84%), HLA-A2, B12 (6.84%), HLA-A2, B18 (6.84%), HLA-B12, DR2 (9.78%) and HLA-B18, DR5 (6.84%). The antigen B5 showed strongest association with DR5 (6.41%; LD = 1.30) as in general Croatian and in some European populations. The results have shown great diversity of HLA haplotypes in Rijeka population which can be the result of admixture with neighborhood immigrating populations during the history.

Chromosome studies in patients with defective reproductive success.

PROBLEM: The objective of this study was to evaluate the contribution of chromosomal anomalies to decreased fertility in humans. METHOD OF STUDY: In order to investigate the aetiology of infertility in our population and to assess the karyotype in a group of infertile couples and individuals with fertility problems, 782 persons (259 couples, 158 male and 106 female) with different clinical diagnoses of sterility and infertility were analysed cytogenetically. RESULTS: The overall frequency of major chromosomal aberration was 13.1% (103/783), which suggests that fertility or sterility problems in this population are due to chromosomal aberrations. Couples experiencing repeated spontaneous abortions, having malformed children or having sterility problems had chromosomal abnormalities in 18.0% (47/259 couples) of the population studied, and constituted chromosomal disorders occured in couples seeking IVF and ICSI with prevalence of 22.2% (8/38 couples), especially minor mosaicism of sex chromosomes in the female partners. The prevalence of chromosome abnormalities in infertile men was 17.7% (28/158), and in subfertile females, it was 26.4% (28/106). CONCLUSIONS: These results could indicate an increased tendency to miotic sex chromosome non-disjuction in humans.

The effect of a compulsory curriculum on ethical attitudes of medical students.

The purpose of the present study was to assess the influence of a compulsory curriculum on first-year medical students. The ethical attitude study was performed at the School of Medicine, University of Rijeka, Croatia. The samples consisted of 171 medical students (68 males and 103 females) interviewed at the beginning of the first year of studies. Some of them, namely 143 (56 males and 87 females) were interviewed again at the end of the same academic year. Data were analysed by applying factor analysis under principal component model and varimax criterion as the rotation model. The results clearly show that the current compulsory curriculum without formal ethical education has a limited influence on first-year medical students. That points to the obvious necessity to implement the medical ethics in the course of medical education.

Maternal serum screening for Down syndrome: a survey of pregnant women's views.

OBJECTIVES: This study was undertaken to assess women's self-reported awareness of Down syndrome before they became pregnant and after they were supposedly informed about screening. We investigated their understanding of the purpose of screening and what a high statistical risk for Down syndrome means, and if there was a high statistical risk whether they would undergo amniocentesis. METHODS: Pregnant women (n=274) ranging from 17 to 43 years of age, with different educational backgrounds, were surveyed by means of a questionnaire which was given to them immediately before blood samples were taken. RESULTS: Women without a college education were significantly less likely then those with a college education to be aware of Down syndrome prior to pregnancy. Many of them reported being unaware of it even after they had been counseled and tested. Women with a lower level of education were also significantly less likely to have a clear understanding of purpose of screening. Fewer than 0.7% of women who were tested said they were not prepared to undergo amniocentesis, and 47.1% said they would consider amniocentesis only after receiving the screening test result. CONCLUSION: Procedures for education women prior to maternal screening must be provided.

Chromosomal anomalies in abnormal human pregnancies.

OBJECTIVE: The aim of this study was to describe the cytogenetic observations on abnormal human pregnancies (anembryonic pregnancy, early fetal loss, and hydatidiform moles), and to detect the most frequent or typical chromosomal aberration for anembryonic pregnancy and early fetal loss. STUDY DESIGN: Abnormal pregnancies were divided into three clinical and morphological groups: (a) anembryonic pregnancy; (b) early fetal loss, and (c) hydatidiform mole. Of the 119 karyotyped tissue samples, 42 (35%) were from anembryonic pregnancies, 64 (54%) from early fetal losses, and 13 (11%) were from hydatidiform moles (6 complete and 7 partial moles). Long-term cultures of chorionic villi and GTG-banding techniques were used for chromosome analysis. RESULTS AND CONCLUSION: The overall frequency of chromosome anomalies among the 119 karyotyped spontaneous abortions was found to be 37.8%. Trisomy (double trisomy included) accounted for 35.6% of all aberrations, followed by polyploidy (33.3%), mosaicism (11.1%), structural abnormalities (4.4%), and monosomy X (2.2%). Although the difference was not statistically significant, single trisomy was the predominant chromosome abnormality found in anembryonic pregnancies (64.3 %) while in cases of early fetal loss, trisomy (double trisomy included) (38.9%) and triploidy (27.8%) were quite frequently present. The frequency of triploidy among all chromosomal abnormalities was 28.9%, and 53.8% of them were found in partial hydatidiform mole. The rest of them were almost exclusively found in early fetal losses. Complete hydatidiform moles (androgenetic in origin) were present in 13.3% of all aberrations, of which 83.3% had a 46,XX, and the rest of them had a 46,XY karyotype.

Screening for Down's syndrome and neural tube defect in Croatia. A regional prospective study.

OBJECTIVE: The purpose of this study was to investigate the efficiency of second-trimester maternal serum screening for Down's syndrome and open neural tube defects using alpha-fetoprotein and free beta-human chorionic gonadotropin as serum markers. METHODS: 3, 188 women underwent testing between 14th and 22nd week of pregnancy. Of all tested patients, 25.4% were >/=35 years old. A cut-off risk of >/=1:250 for Down's syndrome and MS-AFP >/=2.0 MoM for open neural tube defect were considered screen-positive. RESULTS: The detection rate for Down's syndrome was 77.8% (7/9) with 8.2% screen-positive rate (7.9% false-positive rate). When evaluated separately, in patients younger than 35 and in those >/=35 years old, the screen-positive rates were 3.1 and 23.3%, respectively. A total of 52 (1.6%) were found screen-positive for open neural tube defect; 2 cases of encephalocela and 1 case of gastroschisis were confirmed prenatally. CONCLUSION: The respectable number of cases with trisomy 21 identified in this study confirms that routine mid-trimester screening for Down's syndrome including MS-AFP, free beta-hCG and maternal age is useful in identifying pregnancies at increased risk.

Alloimmunization against well defined polymorphic major histocompatibility or class I MHC transfected L cells antigens can prevent poly IC induced fetal death in mice.

METHOD: It is possible to induce increased fetal resorption in a number of inbred murine matings by injecting Poly (I) Poly (C12U) 3.5 days postconception, a maneuver associated with natural killer-mediated damage to the feto placental unit such as occurs in spontaneous fetal resorptions. RESULTS: We show here that alloimmunization can block this effect. In addition, maternal immune responses induced by alloimmunization against isolated mutant class I or class II, as well as by immunization with class I MHC alloantigens (Kd) transfected L cells are sufficient to restore normal fetal viability. It is not necessary that the maternal immune response be specifically directed against paternal alloantigens fr the fetal protection to ensue, since the effect occurs in inbred matings when the mother is immunized against unrelated class I or class II alloantigens. As in previous studies conducted in the murine species, not all MHC alloimmunizations are protective. In addition, as control, immunization with a monomorphic class I MHC molecular (37), transfected L cells, sheep red blood cells or hen egg lysozyme is without effect. CONCLUSION: These results indicate that defined MHC antigens can mediate fetal protection from induced fetal resorption, and suggest that one driving force in promoting MHC antigen polymorphism in mammals is their capacity to confer protection from NK mediated fetal demise.

The proportion of symmetric and asymmetric IgG antibody molecules synthesized by a cellular clone (hybridoma) can be regulated by placental culture supernatants.

The purpose of the present work was to establish whether the placenta is producing factors favoring an increased synthesis of asymmetric IgG antibodies which are known to assume a protective effect upon paternal antigens to which they largely are specific. In this way they can contribute to fetal survival in the maternal uterine environment. The hybridoma cell lines OKT8 (anti-CD8) and 112B4 (anti-DNP) were used in this respect since they synthesized both symmetric and asymmetric molecules of the IgG2a and IgG1 subclasses, respectively, murine isotypes in which anti-paternal antibodies have been detected. The cells were cultured in RPMI 1640 medium supplemented with 10% BCS and different amounts (5, 10, and 20%) of human placental supernatant. After incubation for 3 days at 37 degrees C in a humid chamber containing 5% CO2 the cells were centrifuged and the antibodies were obtained from the culture medium by a purification procedure involving precipitation at 50% ammonium sulfate saturation followed by DEAE-cellulose chromatography. Symmetric and asymmetric antibodies were separated by Con A-Sepharose affinity chromatography, the latter lectin retaining selectively only asymmetric IgG molecules. Both OKT8 and 112B4 hybridomas presenting a stable background synthesis of 15-17% of asymmetric antibodies have shown an increased level reaching 27-28% of these molecules in the presence of 5-10% placental supernatant added to the RPMI 1640 culture medium. These results clearly show that placental factors can up-regulate efficiently the synthesis of asymmetric IgG molecules of different isotypes secreted by plasma cells.

Immunoregulatory factors contributing to fetal allograft survival.

A mammalian fetus expresses a variety of antigens potentially unknown to the immunologically competent mother. Presented here are the results of investigations of maternal immune reactivity to paternally derived antigens of fetoplacental unit, detected at various levels: 1) spleen and distant lymphatic organs, 2) regional lymph nodes draining uterus, and 3) materno-fetal interface. The results suggest that the mother's immune system reacts differently in semiallogeneic pregnancies than in syngeneic ones. The type of the systemic immune response depends on the stage of pregnancy. Increased percentage of CD8+ cells and decreased CD4+/CD8+ cell ratio was found in distant and regional lymphatic organs during pregnancy. The paternal class I MHC antigens expressed on the trophoblast cells are nonpolymorphic molecules which can have a role in immunotrophism of the placenta and in fetal allograft protection.

Complete Freund adjuvant treatment of pregnant females influences resorption rates in CBA/J x DBA/2 matings via progesterone-mediated immunomodulation.

Treatment of pregnant CBA/J females with CFA at day 0.5 and 7.5 of pregnancy significantly reduced the fetal resorption rates from 45% to 29% (P less than 0.05). Supernatants of progesterone-treated spleen cells from CFA treated CBA/J females pregnant of DBA/2 males significantly reduced natural cytotoxicity, while those of untreated identically pregnant mice had no effect. Supernatants of CFA-treated virgin mice blocked natural cytotoxicity to the same extent as those of CFA-treated pregnant mice. These data suggest that nonspecific immunostimulation induces progesterone receptors in spleen cells of CBA mice and that these receptors allow a progesterone dependent suppressive pathway to exert an antiresorptive effect.

Reactivity to alloantigens and polyclonal mitogens and CD4+/CD8+ cell ratio shifts of cervical lymph node and spleen cells during pregnancy in rats.

Cervical lymph node (CLN) cells and spleen cells were harvested from virgin and pregnant rats bearing syngeneic or allogeneic fetuses at all stages of pregnancy including the pre-implantation period. The specific and non-specific alloreactivity of these cells were analyzed in MLR against mitomycin-C treated paternal strain or unrelated cells. Mitogen stimulation of the cell cultures utilized PHA, Con-A and PWM. Cells bearing T cell markers were labeled in an indirect assay using the monoclonal antibodies W3/25 and MRC OX 8. Specific alloreactivity is enhanced at mid-pregnancy in both cell populations. Non-specific alloreactivity was suppressed in the cervical lymph node cells. Spleen cells demonstrated an increased non-specific alloreactivity and T polyclonal mitogen reactivity (PHA and Con-A) at mid-pregnancy. Reactivity to Con-A was depressed in the early phase and at the end of allogeneic pregnancy in the CLN. The CD4+/CD8+ ratio was very low during all phases of pregnancy.