P-332 Management of Thin Endometrium by hysteroscopic instillation of G-CSF mobilized progenitor cells combined with platelet-derived growth factor concentrate into the sub endometrial region-A case series

Study question

Can hysteroscopic instillation of G-CSF mobilized progenitor cells combined with platelet derived growth factor concentrate into subendometrial region help patient with thin endometrium conceive?

Summary answer

Hysteroscopic subendometrial administration of stem cells represents a safe effective alternative method for patients recommended surrogacy, fail to improve despite using all possible treatment options.

What is known already

Thin endometrium is still a challenge in ART, and is considered sub-optimal for transfer and associated with lower implantation and pregnancy rates. For such patients and their treating physicians, chronically thin endometrium results in repeated expensive IVF cycles, cycle cancellations, unplanned cryopreservation of embryos and, in most extreme cases in the utilization of gestational carriers. Strategies like hysteroscopic adhesiolysis, estrogen, vasoactive chemical measures, and infusion of growth factors into the uterus, have little or no effect. Recently, many studies have successfully used stem cells or PRP alone or in combination for rejuvenation of reproductive tissues and organ failure.

Study design, size, duration

Case series study involving 20 patients with persistent non-responsive thin endometrium were included and underwent frozen embryo transfer over a period of 18 months from July 2020-December 2021 at A4 fertility center, Chennai

Participants/materials, setting, methods

20 patients with thin endometrium and more than two implantation failures were included. Two doses of subcutaneous G-CSF were given on Menstrual Cycle Day 3&4, followed by 60ml venous blood aspirated on MCD 5. Seragen’s selective enrichment protocol was used to prepare circulating endothelial progenitor cells and growth factors concentrate. With 2.9mm hysteroscope and single lumen ovum pickup needle harvested cells and growth factors were implanted in sub-endometrial zone on all four walls of cavity.

Main results and the role of chance

20 patients with thin endometrium of less than 7mm and previously more than two implantation failures were included. In spite of routine HRT with Estradiol valerate and intrauterine PRP instillation, endometrium was non-responsive. After another failed attempt using letrozole for ovulation induction to improve endometrial thickness, we ventured into the option of hysteroscopic stem cell instillation. Average endometrial thickness increased from 6.35±0.6mm to 7.32±0.7mm. Out of 20 patients who underwent FET, 12(60%) became pregnant of whom 2(10%) delivered successfully. 6(30%) uneventful pregnancies are ongoing and 4(20%) had miscarriage and 8 patients didn’t conceive are recruited for ET in the next cycle. Many studies have successfully used stem cells or PRP for rejuvenation of reproductive tissues. When these growth-promoting cells and growth factor from platelets are delivered into basal layer which is origin of endometrial cells quality of the endometrium can be improved. While bone marrow is excellent source for obtaining stem cells to treat endometrial pathologies, main challenge is invasiveness of collection. To overcome this, we have adopted G-CSF mobilization to mobilize endothelial progenitor cells from bone marrow into circulation for easy collection and concentration.

Limitations, reasons for caution

Further research is needed to provide opportunity for women with refractory thin endometrium to conceive without surrogacy. Our study provides promising information for future randomized, controlled trials with large sample size in this field.This study has limitation of being small size with the women serving as their own historical controls.

Wider implications of the findings

We demonstrated that the proposed combination of two less invasive yet proven therapeutics combined with targeted delivery could be new ray of hope in females recommended for surrogacy or who fail to improve despite all possible treatment options and reduces emotional and financial burden associated with surrogacy and repeated IVFcycles.

Trial registration number

Not Applicable

Oral administration of schistosome egg antigens and insulin B-chain generates and enhances Th2-type responses in NOD mice

In murine Schistosoma mansoni, parenteral administration of parasite eggs or saline-soluble egg antigens (SEA), generates Th2 T-cell responses to both schistosome-specific and unrelated third-party antigens. Oral administration of insulin to NOD mice suppresses or delays the onset of diabetes by skewing the response toward CD4+ Th2 cells and TGF-beta producing cells. From these two independent sets of observations, we initiated the present study to determine if oral administration of SEA would stimulate Th2-type cytokine responses when mice were fed SEA alone or in tandem with insulin B-chain. Our results show that feeding NOD mice with either insulin B-chain or SEA alone significantly inhibits proliferation to the immunizing antigen. When cytokine profiles were examined, feeding led to a predominance of IL-10 and TGF-beta production. Furthermore, feeding SEA in combination with insulin B-chain augmented the level of IL-10 production to insulin. T-cell lines established from SEA-fed and -immunized mice secreted IL-4 and IL-10 cytokines whereas the T-cell lines from control-fed mice immunized with SEA secreted predominantly IL-2 and IFN-gamma. These results demonstrate that orally administered insulin can induce regulatory T-cells secreting IL-4, IL-10, and TGF-beta and that Th2 responses to oral insulin could be augmented in a synergistic way by feeding SEA and insulin B-chain together.

B-cell outgrowth and ligand-specific production of IL-10 correlate with Th2 dominance in certain parasitic diseases

In many parasitic infections, dominant T helper cell (Th) type-2 CD4+ T cell responses exacerbate the disease. We have previously demonstrated that lacto-N-fucopentaose-III (LNFPIII), a sugar found on soluble egg antigens (SEA) of Schistosoma mansoni, stimulates splenic B cells from parasite-infected mice to proliferate and produce IL-10, a cytokine that promotes the generation of Th2 immune responses. In the present study, we extend our observations on ligand-specific activation of IL-10 producing B cells to leishmaniasis and lymphatic filariasis. We report here that infection with Leishmania major increases the splenic B220+ B cell subset in BALB/c mice, but not BALB/c. xid (lacking B-1 cells and carrying defective B-2 cells). In addition, these B cells secrete large amounts of IL-10 in vitro in response to stimulation with soluble leishmanial extract (LSE), LNFPIII, or SO4-Lewis(x). We also observed that injection of LSE increased the level of peritoneal exudate (PeC) B-1 cells (CD5+B220+) in BALB/c mice, but not C57BL/6, as compared to buffer-injected controls. Further, LSE elicited PeC B cells secreted IL-10 in response to LSE as well as to the sugars tested. A similar differential secretion of IL-10 by splenic B cells from BALB/c and BALB/c.xid was seen after S. mansoni infection. Likewise, injection of soluble microfilarial extract (MFX) resulted in an increase in percentage of PeC B-1 cells in BALB/c mice, but not C57BL/6, and these cells secreted IL-10 in response to stimulation with MFX or phosphorylcholine (PC). Collectively, these results suggest a correlation between expansion of ligand-specific IL-10 producing B and B-1 cells with dominance of Th2-type T cells in mice with the susceptible phenotype for these diseases.

Diagnosis of typhoid fever: detection of Salmonella typhi porins-specific antibodies by inhibition ELISA

Porins are highly immunogenic outer membrane proteins of Salmonella. Sera from typhoid patients contained a high level of IgG antibodies directed to porins of Salm. typhi. Since porins are highly conserved proteins, anti-porins antibodies both from typhoid patients and healthy normals reacted with porins from several Gram-negative bacteria. Therefore, in order to improve the specificity of detecting Salm. typhi porins-specific antibodies, an inhibition ELISA was developed using enzyme-conjugated MoAbs (MP1 and MPN4) specific to Salm. typhi porins. Sera from typhoid patients with positive haemoculture (16 out of 17) inhibited the binding of MP1 to porins, thus showing a positive test for typhoid, whereas sera from patients with other Gram-negative bacterial infections (n = 7) and from healthy volunteers (66 out of 67) were found to be negative. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of this assay were 94.1, 98.7, 97.8, 94.1 and 98.7% respectively. The validity of our inhibition ELISA for typhoid was higher than that of the Widal test. The diagnosis of typhoid fever as early as 3 days after the onset of fever, using a single specimen is possible.

Monoclonal antibodies against Salmonella porins: generation and characterization

Monoclonal antibodies (mAbs) were generated against porins, one of the major outer membrane proteins of Salmonella typhi. Six clones, designated MP1, MP2, MP3 (IgG2ak), MPN4, MPN6 (IgG1k) and MPN5 (IgG2bk) were characterized by enzyme immunoassay (ELISA) for their reactivity to porins from S. typhi, Salmonella paratyphi A, S. paratyphi B, S. paratyphi C, Salmonella choleraesuis, Salmonella enteritidis, Salmonella krefeld, Salmonella panama, Salmonella typhimurium, Escherichia coli B, Shigella flexneri 1b and Pseudomonas aeruginosa. All the clones positive for S. typhi porins showed varying reactivity towards several Salmonella species. However, none of them was positive for porins from other Gram-negative bacteria or for lipopolysaccharide (LPS). The affinity constant of these mAbs, except MPN4, was found to be in the higher range. Dot ELISA revealed that the mAbs recognized porins only in their native form. The results of inhibition ELISA using horseradish peroxidase (HRP)-conjugated MP1 suggest that the clones MP1, MP2, MP3, MPN5 and MPN6 secreted antibodies to identical epitope(s) of a 36-kDa peptide and MPN4 to a different epitope of a 35-kDa peptide. The possible applications of these mAbs were discussed.

Strain dependent & selective modulation of murine humoral immune response by carrageenan

Carrageenan (CGN), a polygalactan extracted from red algae, induced 90 per cent suppression of antibody response to sheep red blood cells in Balb/C strain as compared to the untreated controls. Whereas the treatment failed to induce suppression in C57BL/6 strain. The observed suppression of antibody response was significant on all days tested (up to 40 days) and the suppression induced by CGN was real and not due to any direct effect on antigen or on the assay system followed. On the other hand, as evident from foot-pad thickness, the delayed type hypersensitivity (DTH) was unaltered in Balb/C strain after CGN treatment.

Influence of carrageenan on peritoneal macrophages

BALB/c mice were given five intraperitoneal (i.p.) injections of lambda carrageenan (CGN lambda). Following this treatment, the viability, phagocytic capacity, bactericidal activity, interleukin 1 (IL-1)-producing ability and Ia+ cell content of the peritoneal plastic-adherent macrophage population was analysed. The present study demonstrates the enhancement of bactericidal activity, inhibition of the augmented Ia+ cell content after priming with sheep red blood cells (SRBC), and impairment of IL-1 production by peritoneal macrophages, although their viability and phagocytic function remained unaltered.

Modulation of murine anti-SRBC response by carrageenan: possible mechanism

Carrageenan (CGN), a sulphated polygalactant extracted from red algae, induced antigen-specific suppression of secondary antibody response to SRBC. Unlike the previous studies reported in the literature, in the present study no significant difference could be observed in the number of either total or adherent cells in the peritoneal cavity of CGN treated animals when compared to the untreated controls. However, upon immunization with SRBC, the number of IA and IE positive cells of the treated animals was significantly reduced as compared to the untreated controls. From these results, the possible mechanism in the modulation of immune response by CGN is discussed in the present study.