Cilostazol in Diabetic Neuropathy

Cilostazol is an effective causal therapy for preventing paclitaxel-induced peripheral neuropathy by suppression of Schwann cell dedifferentiation

Chemotherapy-induced peripheral neuropathy (CIPN) can lead to discontinuation of chemotherapy and is consequently a serious impediment to effective cancer treatment. Due to our limited understanding of mechanisms underlying the pathogenesis of CIPN, no causal therapy has been approved for relief of this condition. We previously demonstrated that taxanes (paclitaxel and docetaxel) induce Schwann cell dedifferentiation, characterized by increased expression of p75 and galectin-3, ultimately leading to demyelination. These changes appear to be responsible for CIPN pathogenesis. This study was designed to identify a novel candidate therapeutic for CIPN with the ability to suppress paclitaxel-induced Schwann cell dedifferentiation. Given that elevation of cyclic adenosine monophosphate (cAMP) signaling participates in Schwann cell differentiation, we performed immunocytochemical screening of phosphodiesterase (PDE) inhibitors. We found that the PDE3 inhibitor cilostazol strongly promoted differentiation of primary cultures of rat Schwann cells via a mechanism involving cAMP/exchange protein directly activated by cAMP (Epac) signaling. Co-treatment with cilostazol prevented paclitaxel-induced dedifferentiation of Schwann cell cultures and demyelination in a mixed culture of Schwann cells and dorsal root ganglia neurons. Notably, continuous oral administration of cilostazol suppressed Schwann cell dedifferentiation within the sciatic nerve and the development of mechanical hypersensitivity in a mouse model of paclitaxel-related CIPN. Importantly, cilostazol potentiated, rather than inhibited, the anti-cancer effect of paclitaxel on the human breast cancer cell line MDA-MB-231. These findings highlight the potential utility of cilostazol as a causal therapeutic that avoids the development of paclitaxel-related CIPN without compromising anti-cancer properties.

Off-label prescriptions in diabetic foot

Prescription of a drug outside of the indications for which it was originally approved by regulators is internationally known as "off-label" prescription. We describe off-label treatments for the diabetic foot reported in international scientific literature. This is a qualitative and descriptive bibliographical review based on the results of a search of the Medline international database. The criteria for review were publication between January 1985 and November 2013, and the MeSH (Medical Subject Heading) keywords "off-label use" OR "off-label" OR "off-label prescribing" plus "diabetic foot" were input on the search form. Nine studies were selected that contained information about off-label treatments for the diabetic foot. We conclude that the practice of off-label prescribing has potential benefits. In some situations an off-label prescription is the only treatment available for patients, either because a more targeted drug does not exist, or because other methods of treatment are ineffective or unavailable due to patient intolerance.

Cilostazol prevents foot ulcers in diabetic patients with peripheral vascular disease

Diabetic patients are at high risk of foot ulcerations that may lead to limb amputations with important socio-economic impact. Peripheral vascular disease may be frequently associated in diabetes mellitus type II with its main symptom, intermittent claudication. Many studies reported the known efficacy of cilostazol in treating vascular claudication. Metalloproteinase-9 (MMP-9) seems to be a biochemical marker implicated in chronic wounds and in particular in diabetic foot ulcers. Cilostazol appears to have a lowering effect on MMP-9 levels and this may suggest a beneficial effect in order to prevent or retard the onset of foot ulcer in diabetic patients. In our study, two groups of diabetic patients with peripheral vascular disease were divided into two groups according to the presence of claudication in order to receive cilostazol. Group A (31 patients without claudication) were not eligible to receive cilostazol whereas Group B (47 patients with claudication) received cilostazol administration for 24 weeks (100 mg orally twice daily). Median follow up was of 16 months. During the follow up, 4·25% of patients of Group B and 35·48% of patients of Group A (P < 0·01) showed onset of foot ulceration. Although further randomised and controlled studies are required cilostazol seems to show beneficial effects for primary prevention of diabetic foot ulcers.

Determinants of microbial load in infected diabetic foot ulcers: a pilot study

We examined the determinants of microbial load in infected diabetic foot ulcers in 62 patients (38 men and 24 women, mean age: 65.63 ± 12.71 years) with clinically infected diabetic foot ulcers. Tissue cultures were taken from ulcers by 4 mm punches. Ulcer grade (University of Texas classification), neuropathy disability score (NDS), neuropathy symptom score (NSS), ankle-brachial index (ABI), perfusion, extent, depth, infection, and sensation (PEDIS) grade of diabetic foot infection, and laboratory parameters were evaluated in all patients. Total microbial load was positively correlated with the number of isolates on tissue cultures (r s = 0.544, P < 0.001), white blood cell count (WBC) (r s = 0.273, P = 0.032), and platelet count (PLT) (r s = 0.306, P = 0.015). It also exhibited a borderline insignificant positive correlation with PEDIS infection grade (r s = 0.246, P = 0.053). In stepwise linear regression analysis, the number of isolates on tissue cultures and WBC were identified as the only two significant parameters accounting for 38% of the variation in the log of total microbial load (adjusted R (2) = 0.380, P < 0.001). In conclusion, patients with infected diabetic foot ulcer exhibit a positive correlation of total microbial load with the number of isolates on tissue cultures, WBC and PLT.

Mean Platelet Volume and Platelet Distribution Width in Patients With Chronic Obstructive Pulmonary Disease

We evaluated mean platelet volume (MPV; an indicator of vascular risk) and platelet distribution width in patients with stable chronic obstructive pulmonary disease (COPD; n = 85). We also included a control group of 34 smokers without airflow limitation. Mean platelet volume was significantly higher in patients with COPD (10.69 ± 1.0 vs 9.96 ± 1.10 fL, P < .001) than in the smoker controls. White blood cell (WBC) count was also significantly higher in patients with COPD than in the smoker controls (10 642 ± 1247 vs 7136 ± 1887/μL, P < .001). There was a correlation between MPV and WBC in patients with COPD, especially in those at stage III ( r = .530, P = .004) and IV ( r = .389, P = .023). Mean platelet volume did not correlate with any indices of COPD severity. In patients with COPD, MPV and WBC levels are higher than those of smokers with normal pulmonary function and are significantly correlated. Whether these effects relate to vascular risk in patients with COPD remain to be established.

The ε4 allele of the APOE gene is associated with more severe peripheral neuropathy in type 2 diabetic patients

We examined the association between the ε4 allele of the apolipoprotein E gene and severity of peripheral neuropathy in 234 patients with type 2 diabetes mellitus (T2DM). Based on the Neuropathy Disability Score (NDS), patients were divided into group A (NDS ≤ 6: mild or no neuropathy) and group B (NDS > 6: severe neuropathy). In each group, patients were further divided into ε4 carriers and non-ε4 carriers. In multivariate analysis, a more than 5-fold increased risk of severe neuropathy was associated with ε4 carrier status (adjusted odds ratio [aOR]: 5.26, 95% confidence interval [CI]: 2.24-12.31, P = .0001). The other significant risk factors for severe neuropathy included male gender (aOR: 2.08, 95% CI: 1.05-4.14, P = .036), diabetes duration (aOR: 1.05, 95% CI: 1.00-1.09, P = .039), and hemoglobin A1c (aOR: 1.32, 95% CI: 1.05-1.66, P = .020). In conclusion, the ε4 carrier status appears to be associated with severe peripheral neuropathy in T2DM.