Connective tissue responses in blacks in relation to disease: further observations

Additional information is presented in support of the hypothesis (Polednak: Am. J. Phys. Anthropol. 41:49-58, 1974) that in some black populations certain connective-tissue responses, which are involved in protection against infection and repair after injury, also may predispose to specific chronic diseases. These diseases include some autoimmune disorders (i.e., systemic lupus erythematosus, sarcoidosis, and scleroderma) and various benign and malignant tumors involving connective-tissue cells. Complex interactions between genetic factors (HLA and non-HLA loci) and environmental agents may be involved both in the etiology of these autoimmune diseases and in population differences in the incidence of these diseases. A framework is reviewed whereby cellular responses to infectious agents, involving chiefly immunoglobulin-producing cells and macrophages, may have consequences in terms of pathogenesis of specific chronic diseases more common in some black populations. The possible role of natural selection in maintaining some of these diseases is also considered, along with the need for involvement of biomedical anthropologists in their investigation.     

Adjuvance in refractory keloids using electron beams with a spoiler: Recent results

Aim

To present clinical results of adjuvant irradiation of excised refractory keloid wounds using a novel bolus-free technique developed within our group to irradiate the skin surface with a linear accelerator.

Background

The use of a bolus to increase surface dose over a newly excised keloid presents several problems. Previous solutions are unsatisfactory. Our technique is promising but needs to be evaluated in practice.

Materials and methods

Twenty refractory skin keloids in 19 patients were excised and irradiated in Hospital Plató (Barcelona, Spain) using a 6 MeV electron beam with a 4-mm aluminium spoiler. 15 Gy in fractions of 3 Gy were delivered to the excision site plus a safety margin. All patients were examined during the follow-up (median: 40 months, interval: 12–68 months) and toxicities were recovered.

Results

At the end of the follow-up period, 76% of the cases had not recurred, while the complete response rate amounted to 53%. Residual hypertrophic scars were classified as partial responses. After therapy, itching and pain were observed in 30% of the patients, as well as one telangiectasia and two hyperchromatic scars.

Conclusion

Our technique avoids using a bolus while combining the benefits of electron beam therapy in keloids (fewer secondary effects, and fewer and shorter treatments) with a dose deposition adequate for skin surface treatments. Our results are in line with the most successful therapies evaluated in the literature, as secondary effects are acceptable and recurrence rates are low.