Lymphocyte transformation in subjects with nodulo cystic acne

About local administration of antibacterial drugs for acne therapy

The review summarizes and systematizes data accumulated in the world research literature, which are related to the role of P. acnes in the pathogenesis of acne, its microbiology and antibacterial resistance; it also examines antibacterial drugs for the external therapy of acne and recommendations for their use.

The role of Propionibacterium acnes in acne pathogenesis: facts and controversies

We have come a long way since 1896, when it was first suggested that Propionibacterium acnes, found in acne lesions, was the cause of acne. Although several lines of evidence suggest the direct role of P acnes in acne, the mechanism by which P acnes contributes to the pathogenesis of acne is debated. The importance of P acnes in the induction and maintenance of the inflammatory phase of acne has been established. Emerging data that inflammatory events occur in the very earliest stages of acne development have reopened the debate about the potential involvement of this microorganism in comedogenesis and acne initiation.

Resolution of inflammatory acne vulgaris may involve regulation of CD4+ T-cell responses to Propionibacterium acnes

BACKGROUND

Propionibacterium acnes has been strongly implicated in inflammatory acne. However, its role in the disease is unclear. It has been hypothesized that an immune response to P. acnes and/or P. acnes heat shock proteins (HSPs) may play a role in the pathogenesis of inflammatory acne.

OBJECTIVES

To compare the cell-mediated immune response to P. acnes and HSPs in acne patients, nonacne controls and individuals with resolved acne.

METHODS

The proliferative response of peripheral blood mononuclear cells (PBMC) from acne patients, resolved acne donors and healthy controls to P. acnes, P. acnes HSP60 and HSP70, and mycobacterial HSPs was assessed by lymphocyte transformation assay (LTA). The proliferative response of purified CD4+ T cells was further analysed by limiting dilution analysis (LDA). Contingency tables (G-test) were used to analyse the proportion of individuals in each group showing a positive proliferative response for LTA or data fitting single-hit kinetics for LDA.

RESULTS

Analysis of stimulation of PBMC with P. acnes, P. acnes HSP60 and HSP70 in the LTA showed the proportion of positive responders to be independent of subject group. However, the proportion of acne patients with a positive response to mycobacterial HSPs was significantly higher than those for the other subject groups. Analysis of LDA data showed the proportion of resolved donors with responses to P. acnes fitting the single-hit kinetics model to be significantly lower than those of the other groups. There were no significant differences in responses to other antigens.

CONCLUSIONS

The significantly lower proportion of resolved donors demonstrating a single-hit kinetics response to P. acnes by LDA may represent negative regulation of the CD4+ T-cell response to P. acnes in these subjects.

The Role of Inflammation in the Pathogenesis of Acne and Acne Scarring

Evidence now supports a pivotal role for cellular inflammatory events at all stages of acne lesion development, from preclinical initiation to clinical presentation of active lesions through to resolution. The emphasis has moved from acne as a primarily hyperproliferative disorder of the sebaceous follicle to that of an inflammatory skin disorder. However, although the sequence of events leading to lesion formation has become clearer, the triggers for initiation remain speculative. The development of noninvasive techniques to detect preclinical "acne-prone" follicles is essential before triggers for initiation can be defined. Finally, the differences highlighted in the inflammatory profiles of inflamed lesions from patients who scar, as compared with other nonscarring acne patients reinforces the view that acne is a disorder, which embraces a number of pathologies.

Inflammation in acne scarring: a comparison of the responses in lesions from patients prone and not prone to scar

BACKGROUND

Many patients with inflammatory acne suffer from significant scarring, which is disfiguring and difficult to treat. A cell-mediated immune response is considered to be involved in the pathogenesis of acne, although the extent of this response has been found to differ among patients.

OBJECTIVE

To assess whether there were differences in the cell-mediated immune responses at different time points in inflamed lesion development and resolution in patients who were prone (S patients) and those with the same degree of inflamed acne who were not prone (NS patients) to develop scarring.

METHODS

Cellular and vascular markers were investigated using standard immunohistochemical techniques on biopsies of inflamed lesions of known duration, i.e. < 6 h (n = 14), 24 h (n = 14), 48 h (n = 10), 72 h (n = 10) and 6-7 days (n = 11) from the backs of acne patients.

RESULTS

In early lesions from NS patients there was a large influx of CD4+ T cells, macrophages and Langerhans cells with a high number of cells expressing HLA-DR. Also there was significant angiogenesis and vascular adhesion molecule expression. Cell recruitment peaked in 48 h lesions, after which leucocyte numbers decreased and vascular activity returned to normal. Of the T cells, only 50% were memory/effector (CD45RO+) and naive (CD45RA+) cells, while the remainder were unclassified (CD45RO-, CD45RA-). In early lesions from S patients, CD4+ T cell numbers were smaller, although a high proportion were skin homing memory/effector cells. Langerhans cell numbers and cellular HLA-DR expression were low, while numbers of macrophages, blood vessels and vascular adhesion molecules were high. In resolving lesions angiogenesis remained high, with a further influx of macrophages and skin homing memory/effector cells and increased cellular HLA-DR expression.

CONCLUSIONS

The cellular infiltrate was large and active with a greater nonspecific response (few memory T cells) in early lesions of NS patients, which subsided in resolution. In contrast, a predominantly specific immune response was present in S patients, which was initially smaller and ineffective, but was increased and activated in resolving lesions. Such excessive inflammation in healing tissue is conducive to scarring and suggests that the use of topical anti-inflammatory treatments would be appropriate for these patients.

Propionibacterium acnes and inflammation in acne; P. acnes has T-cell mitogenic activity

BACKGROUND

Circumstantial evidence suggests that Propionibacterium acnes has a role in the inflammation of acne. This could be effected by antigenic or superantigenic or mitogenic reactions.

OBJECTIVES

The purpose of this investigation was to determine whether P. acnes had only antigenic activity or additional superantigenic and mitogenic activity.

METHODS

A lymphocyte transformation assay was used to detect responses to a mixture of eight P. acnes whole cell isolates, and their supernatant culture fluids. In order to determine the nature of T-cell reactions to P. acnes cells a mouse-antihuman major histocompatibility complex class II monoclonal antibody was used in the lymphocyte transformation assay to inhibit the antigenic stimulation of lymphocytes. An analysis of the T-cell receptor (TCR) variable region beta (BV) repertoire was undertaken using flow cytometry of the unstimulated and stimulated cells.

RESULTS

Peripheral blood mononuclear cells (PBMNC) from adults with no history of acne responded strongly to stationary growth phase cells of P. acnes, less strongly to cells in the exponential growth phase. No response was detected to supernatant culture fluids. PBMNC from five cord blood samples (CBMNC) responded maximally after 3 and 7 days of incubation with stationary growth phase cells of P. acnes. The reaction of CBMNC to P. acnes cells was not suppressed completely by the blocking antibody. The analysis of the TCRBV repertoire indicated that P. acnes induced no deletion or over-representation of certain BV element-bearing T cells. The TCRBV analysis was repeated after preincubation with the blocking antibody. Deletion of T cells bearing certain BV components occurred and there was no over-representation of T cells carrying certain BV components.

CONCLUSIONS

Two mechanisms of lymphocyte activation by P. acnes cells are proposed, antigen and mitogen driven. These results are consistent with the histological evidence of inflammation in acne lesions.

Post-acne scarring: a short review of its pathophysiology

The onset of acne is an expected phenomenon in adolescence. However, its arrival produces long-term psychological and physical sequelae for the individual. A review of available data illustrates the pathophysiological sequence of the advent of post-acne scarring from its humble beginnings as a microscopic comedone to its eventual devastating end point of indented or exophytic scars. Acne scarring shows many different forms and is explainable by the depth and severity of the antecedent inflammation and the ability of the individual to heal these lesions. Post-acne scarring is debilitating and socially disabling for many and is the avoidable outcome of untreated or inadequately treated acne. Treatment will depend on the resultant scar topography.

Acne: a review of immunologic and microbiologic factors

Acne vulgaris is a self-limiting skin disorder seen primarily in adolescents, whose aetiology appears to be multifactorial. The four main aetiological factors are hypercornification of the pilosebaceous duct, increased sebum production, colonization with Propionibacterium acnes, and subsequently the production of inflammation. Considerable investigation has addressed the immunologic reaction to extracellular products produced by the acne-causing organism, P acnes. The immunologic response involves both humoral and cell-mediated pathways. Further research should clarify the role of complement, cytotoxins, and neutrophils in this acne-forming response.

Inflammation in acne vulgaris

Recent findings suggest that an overly vigorous immune response to Propionibacterium acnes may be the fundamental problem in patients with inflammatory acne. These data and evidence for the antiinflammatory effects of acne medications are reviewed.

Detection of Propionibacterium acnes polypeptides which have stimulated an immune response in acne patients but not in normal individuals

Patient and normal volunteer sera were used as probes in two-dimensional PAGE of P. acnes culture supernatant fluid and cell extracts to determine whether specific P. acnes polypeptides were associated with the immune reaction in acne. Eight polypeptides, M(r) 20 to 131 x 10(3), pI 4.7 to 6.5 in the cell extract, and 7 polypeptides M(r) 10 to 24 kD, pI 4.8 to 7.5 in the culture supernatant fluid were specifically highlighted by patient sera and not volunteer sera. These polypeptides were not related to described extracellular enzymes of P. acnes. It is possible that these polypeptides are involved in the induction of acne.

Musculoskeletal syndromes associated with acne

The acne conglobata (AC)-, acne fulminans (AF)-, and isotretinoin-associated musculoskeletal syndromes are three distinct clinical entities. The AC-associated musculoskeletal syndrome occurs primarily in black men over the age of 22, who develop sacroilitis with or without a peripheral arthropathy. In contrast, the AF-associated musculoskeletal syndrome is found almost exclusively in white male teenagers. Fever, weight loss, and arthralgias are prominent components of this syndrome. A unique feature of the AF-associated musculoskeletal syndrome is osteolytic lesions that occur most frequently in the clavicle, sternum, long bones, and ilium. The isotretinoin-associated musculoskeletal syndrome occurs with equal frequency in male and female acne patients. Mild, transient myalgias and arthralgias are very common and do not require discontinuation of isotretinoin therapy. Asymptomatic, small, hyperostotic lesions of the spine occur in approximately 10% of acne patients with the isotretinoin-associated musculoskeletal syndrome.

Osteomyelitis-like bone lesions in acne fulminans

Two young males with acne fulminans (AF) are described. In addition to severe skin lesions, they had musculoskeletal symptoms including bacteriologically negative osteolytic lesions in the clavicles. Both patients received antibiotics for suspected septic infections. The response was unsatisfactory in both patients, and combination treatment with prednisolone was started. A favourable response was observed, and a relapse occurring in the first patient was controlled by steroids alone. The possible pathomechanism of bone lesions in AF is discussed.

A histological and immunocytochemical study of early acne lesions

We examined 69 biopsies of acne lesions known to be 6, 24 or 72 h old and found that the lymphocyte was the predominant cell at 6 and 24 h. The helper:suppressor T cell ratio in the inflammatory infiltrate was 2.8:1. Polymorphonuclear leukocytes were increasingly seen at 24 and 72 h and were associated with disruption of the duct. We hypothesize that this early lymphocytic infiltrate represents a cell mediated immune response to an antigen within the duct lumen.

IgG subclasses in acne vulgaris

IgG subclasses were measured in male patients with very low grade or severe acne. No IgG subclass deficiencies were found. Patients with severe acne had a significant increase in total IgG attributable to their exposure to antigens which stimulate the production of antibodies in the IgG2 and IgG3 subclasses.

Lymphocyte subpopulations in patients with acne vulgaris

T- and B-lymphocyte subpopulations were measured in the peripheral blood of patients with varying severity of acne and in acne-free control subjects. Increased severity of acne correlated with an increased number of T lymphocytes, helper T cells and B cells, while the number of suppressor T cells remained normal and did not alter significantly. This evidence suggests that there is no lack of regulation of the immune response in acne patients.

Chemotactic efficiency of various chemoattractants for polymorphonuclear leukocytes in inflammatory acne vulgaris

The chemoattractant efficiencies of a Propionibacterium acnes (P. acnes) cell wall preparation, a P. acnes culture supernatant, and a soluble comedonal extract in the presence and absence of autologous serum for polymorphonuclear leukocytes (PMNs) have been compared in the present study. It has been found that all three preparations have no or very little chemotactic activity for PMNs in the absence of serum. In the presence of autologous serum chemotactic factors is generated by all preparations via the alternative complement pathway. The relative efficiencies of the various preparations to induce chemotactic factor by the alternate complement pathway has been evaluated. Based on the bacterial numbers of the original preparations from which the test preparations had been derived the comedonal extract appears to be more efficient in generating chemotactic factor than the other preparations. It is concluded that in vivo generation of chemotactic factors occurs mainly via the alternate complement pathway activated by soluble comedonal factors diffusing through the follicular wall.

Therapy of acne

Today acne vulgaris is a disease which can be well controlled using a combination of topical, systemic, and physical therapeutic modalities. However, successful acne management depends to a large extent on physician interest and the ability of the physician to apply therapy to the evolutionary stage of the disease and to the disturbed pathogenetic mechanisms. It is this author's opinion that grades I and II comedonal and papulopustular acne can be effectively treated solely with topical preparations, particularly the concurrent use of tretinoin with benzoyl peroxide or topical antibiotics. The majority of patients with grades III and IV inflammatory disease require oral antibiotics in addition to aggressive topical treatments. Intralesional steroids can be effective in all grades of acne when lesions develop an inflammatory nodulocystic quality. The physician should consider the use of estrogen (in females) or oral vitamin A in the small group of patients with grades III and IV inflammatory-cystic acne that has been unresponsive to conventional therapy. Combined systemic therapies of high-dose antibiotics, systemic corticosteroids, and sulfones clearly take precedence over topical preparations in conglobate acne and acne fulminans. Finally, oral isotretinoin, alone and perhaps in combination with more conventional modalities, should play an important role in the future management of severe inflammatory-cystic acne.

Delayed skin test reactivity to Propionibacterium acnes correlates with severity of inflammation in acne vulgaris

Propionibacterium acnes is the bacterial species most consistently isolated from acne lesions. Intradermal injection of a heat-killed suspension of P. acnes induced a delayed erythematous and often popular inflammatory reaction which was maximal after 24-48 h. This response was dose related and was probably mediated at least partly by immune mechanisms. In eighty-one subjects with acne of varying severity of the acne. These findings indicate that the host response to P. acnes is an important variable in determining the severity of inflammatory acne.

Sebaceous gland suppression in female acne patients by combined glucocorticoid-oestrogen therapy

Women with severe acne were treated with a combination of oestrogen and a low dose of glucocorticoid daily in order to suppress their androgen production. This combination therapy reduced their sebum production by 50%, with a concomitant improvement in their acne.

Complement C3 and immunoglobulin in inflammatory acne vulgaris

In patients with moderate to severe inflammatory acne, complement (C3) was detected by immunofluorescence in sixteen early inflammatory acne lesions but in only one of thirteen biopsies of non-inflamed skin from acne sites. C3 deposition occurred particularly in the walls of small dermal blood vessels and at the dermo-epidermal junction. IgM was identified in vessel walls in four of sixteen early lesions. In eight late inflammatory lesions C3 deposition was much less prominent and was present in vessel walls in only two. None of the late lesions showed vascular deposition of IgM. The observations indicate that complement activation occurs in inflammatory acne and it is suggested that this may play a pathogenic role in the inflammation.

The chemoattractant properties of comedonal components

Acculation of clusters of polymorphonuclear leukocytes (PMN) along the periphery of the walls of comedones (predominantly of the closed variety), has been described as the first change marking the transition of quiescent, noninflamed lesions in acne, into inflammatory ones. The present study analyzed the chemoattractant properties of different comedonal components for human PMN in an effort to evaluate the potential significance of these substances in stimulating the chemotactic response of PMN in the initial phases of inflammatory acne. It was found that the lipids extracted from pooled comedones had chemotactic activity for PMN in vitro. Beyond that, all chemotactic activity in comedones was related to bacteria. Propionibacterium acnes produced low molecular weight, dialyzable, heat stable chemotactic factors which were released into culture medium during bacterial growth. In addition to the extracellular cytotaxins, P. acnes whole cells and other extracellular products were strong cytotaxigens and activated heat labile chemotactic factors in human and guinea pig serum.

Analysis of the water soluble extract of comedones

The water soluble fraction of 713 open comedones, pooled from both the face and back of 47 subjects representing all grades of acne, were analyzed for total protein content, carbohydrate content, and for identification of specific proteins. In the water soluble fraction, the protein content represented 11.5%, and carbohydrate content 0.2% of the total comedonal crude weight. Esterase and hyaluronidase activity was demonstrated. Propionibacterium acnes antigenic material, serum albumin, and serum Zn alpha 2 glycoprotein, a minor serum constituent, were identified by immunodiffusion and immunoelectrophoresis.

Cellular immunity to P. acnes in the normal population and patients with acne vulgaris

Patients with varying degrees of acne, acne-free adult controls and samples of cord blood were investigated for cell mediated immunity to P. acnes using a leukocyte migration inhibition test. Despite the fact that the mean migration index tended to decrease with acne severity, only the patients with severe acne showed cell-mediated immunity. It is suggested that when cellular immunity arises it is a late event which may contribute to inflammation but is probably not a factor in its initiation.