Immunological functions of the human prepuce

The demonisation of the human male prepuce has been an unscientific process, even though some research, on the surface, might seem to support it. In the late 19th century, when male circumcision came into vogue in medicine in the United States, there was near universal acceptance among American medical professionals that circumcision was an eVective treatment for such “diseases” as masturbation, headache, insanity, epilepsy, paralysis, strabismus, rectal prolapse, hydrocephalus, and clubfoot. Leading medical journals published thousands of case reports demonstrating these and other miraculous therapeutic benefits from preputial amputation. The notion that circumcision improves hygiene and prevents sexually transmitted diseases (STDs) originated at the same time in the context of the discourse over racial and moral hygiene. The peculiar American phenomenon of mass newborn (that is, involuntary) circumcision is a product of the cold war era. United States doctors readily embraced the concept of mass, involuntary circumcision just as they had embraced involuntary sterilisation and other eugenic measures— practices rejected by almost all other Western nations. Mass circumcision peaked in the 1970s, when almost 90% of male neonates in the United States were circumcised. Since then, the rate has declined, but circumcision industry spokesmen have added to the list of diseases that circumcision allegedly prevents and cures. Historically, the most common reason given for circumcision has been that it prevents masturbation. Today, the most common reason given is that it inhibits the transmission of STDs, even though rigorously controlled studies have consistently shown that circumcised males are at greater risk for all major STDs than males whose penises are intact. Circumcision advocates are now claiming that circumcision prevents AIDS. A review of the scientific literature, however, reveals that the actual eVect of circumcision is the destruction of the clinically demonstrated hygienic and immunological properties of the prepuce and intact penis. The sphincter action of the preputial orifice functions like a one way valve, blocking the entry of contaminants while allowing the passage of urine. 8 Ectopic sebaceous glands concentrated near the frenulum produce smegma. This natural emollient contains prostatic and seminal secretions, desquamated epithelial cells, and the mucin content of the urethral glands of Littre. 14 It protects and lubricates the glans and inner lamella of the prepuce, facilitating erection, preputial eversion, and penetration during sexual intercourse. The inner prepuce contains apocrine glands, which secrete cathepsin B, lysozyme, chymotrypsin, neutrophil elastase, cytokine (a non-antibody protein that generates an immune response on contact with specific antigens), and pheromones such as androsterone. Lysozyme, which is also found in tears, human milk, and other body fluids, destroys bacterial cell walls. The natural composition of preputial bacterial flora is age dependent and similar to that of the eyes, mouth, skin, and female genitals. Washing the preputial sac was once thought to aid hygiene. Washing a stallion’s preputial sack with soap, however, encourages the growth of pathogenic organisms. Washing the human prepuce with soap is a common cause of balanoposthitis. Fussell et al have claimed that the prepuce is predisposed to colonisation by pathogenic bacteria, but they did not measure naturally occurring bacterial flora in living cohorts with undisturbed preputial microenvironments. They measured bacterial rates in dead, amputated, chemically treated prepuces inoculated with virulent strains of pathogenic bacteria— conditions that represent no known biological or behavioural reality. Animal experiments reveal that in the presence of hydrogen peroxide and halide or pseudohalides, soluble peroxidase in the prepuce has an antimicrobial activity. Plasma cells in the mucosal lining of the bovine prepuce secrete immunoglobulin under the epidermis that diVuses across the epidermis into the preputial cavity. In response to pathogenic bacterial infection, preputial plasma cells increase. Antibodies in breast milk supplement genital mucosal immunity in infants. Oligosaccharides in breast milk are ingested, then excreted in the urine, where they prevent Escherichia coli from adhering to the urinary tract and inner lining of the prepuce. An 8 year prospective study that controlled for genitourinary abnormalities found no diVerence in the rate of upper urinary tract infections between circumcised and intact boys. There are no histological studies that validate the claim that the sclerotic keratinisation of the epithelium of the surgically externalised, desiccated glans penis, meatus, or scar of the circumcised penis creates a barrier against infection. The higher rate of STDs in circumcised males might well be the result of Sex Transm Inf 1998;74:364–367 364