Cord Blood Serum in the Treatment of Ocular Surface Diseases

The regular collection and banking of cord blood remaining in the placenta after baby's delivery started in the early 1990s and was prompted by the observation that cord blood shows an immunological immaturity which allows to avoid any matching between donor-mother source and patient-recipient, it contains a number of haemopoietic progenitor and stem cells and is therefore potentially and safely useful in the field of regenerative medicine.

Cord blood collection occurs after the umbilical cord has been cut and is extracted from the fetal end of the cord. After collection, the cord blood unit bag is delivered to the lab, processed and then cryopreserved.

The main current clinical use of cord blood is allogeneic transplantation in patients suffering from severe blood diseases but physicians and researchers are making significant progresses evaluating the safety and efficacy of umbilical cord blood stem cells for therapeutic uses far beyond their uses for blood disorders.

Umbilical cord serum (UCS) contains many growth factors and especially EGF and TGF-beta1 concentrations are two-three times higher than in peripheral blood serum and much higher than in tears and is sufficient to prevent squamous metaplasia. In addition, UCS contains anti-inflammatory cytokines with protective effect.

Current therapy for SS-I and GVHD related dry eye depends upon clinical severity of the disease. From mild to progressively severe involvement of corneal epithelial damage , tear substitutes, FANS, steroids, Cyclosporin A, contact lens shields can be topically applied alone or in combination. Autologous serum eyedrops can be an option in severe cases as well, since it supplies epithelial growth factors to the healing process of epithelium.

The use of autologous serum eyedrops, however, is a controversial issues in diseases where inflammatory cytokines are present in peripheral blood, such as GVHD.

The use of cord blood serum based tear substitutes has been recently proposed in the literature for the treatment of ocular surface diseases and neurotrophic keratitis, because it contains growth factors, neurotrophic factors and essential components of tears. Moreover, serum from cord blood is readily available from cord blood banks as quality controlled product and is therefore theoretically attractive for topical use in ophthalmology.

The use of cord blood serum eyedrops as a biological preparation can display in itself efficacy features higher than the other drugs in terms of healing and anti-inflammatory properties in absence of any chemical compound.

In Italy biological products for topical use in ophthalmology to treat corneal epithelial severe defects are not available. The originality of the present study is based on the optimization and standardization of biological eyedrops prepared from cord blood serum. The efficacy and safety of the product for topical use in ocular surface diseases will be evaluated .

For the purpose, the following methods will be applied at baseline and endpoint (28 days of treatment with UCS eyedrops):

• Patients' subjective symptoms evaluation by a validated questionnaire for dry eye (OSDI)
• Slit Lamp examination and evaluation of Tear Film Break Up Time, corneal fluorescein staining score, conjunctival lissamine green staining score, staining will be recorded with digital photos to estimate the healing area in the follow up
• Schirmer I test to evaluate tear production
• Corneal sensitivity test (measured with a Cochet-Bonnet esthesiometer)
• Tear osmolarity, (TearLab, TearLab S.Diego) an indicator of the ability of the patient to compensate
• Tear Clearance Rate, a global indicator of tear production and tear evaporation
• Tear Proteomic to evaluate tear protein profile
• Corneal and Conjunctival inflammatory marker evaluation on cells collected by imprint and scraping cytology

Data will be statistically evaluated after 28 days treatment and matched vs baseline by using the descriptive statistics for paired data. Statistic outcomes will be analyzed with caution due to the non-randomized study design.

Inclusion criteria

• to suffer from GVHD after bone marrow transplantation or SS-I
• presence of permanent or transient corneal epithelial defects scored > 2 , according to DEWS severity classification
• to be in a general healthy condition
• signature of study consent for participation and personal data treatment.

Exclusion criteria

• to suffer from glaucoma and being under treatment with antiglaucomatous drugs
• to have received refractive surgery over the past year