Consequences of cathepsin C inactivation for membrane exposure of proteinase 3, the target antigen in autoimmune vasculitis

Membrane-bound proteinase 3 (PR3^m) is the main target antigen of anti-neutrophil cytoplasmic autoantibodies (ANCA) in granulomatosis with polyangiitis, a systemic small-vessel vasculitis. Binding of ANCA to PR3^m triggers neutrophil activation with the secretion of enzymatically active PR3 and related neutrophil serine proteases, thereby contributing to vascular damage. PR3 and related proteases are activated from pro-forms by the lysosomal cysteine protease cathepsin C (CatC) during neutrophil maturation. We hypothesized that pharmacological inhibition of CatC provides an effective measure to reduce PR3^m and therefore has implications as a novel therapeutic approach in granulomatosis with polyangiitis. We first studied neutrophilic PR3 from 24 patients with Papillon-Lefèvre syndrome (PLS), a genetic form of CatC deficiency. PLS neutrophil lysates showed a largely reduced but still detectable (0.5-4%) PR3 activity when compared with healthy control cells. Despite extremely low levels of cellular PR3, the amount of constitutive PR3^m expressed on the surface of quiescent neutrophils and the typical bimodal membrane distribution pattern were similar to what was observed in healthy neutrophils. However, following cell activation, there was no significant increase in the total amount of PR3^m on PLS neutrophils, whereas the total amount of PR3^m on healthy neutrophils was significantly increased. We then explored the effect of pharmacological CatC inhibition on PR3 stability in normal neutrophils using a potent cell-permeable CatC inhibitor and a CD34⁺ hematopoietic stem cell model. Human CD34⁺ hematopoietic stem cells were treated with the inhibitor during neutrophil differentiation over 10 days. We observed strong reductions in PR3^m, cellular PR3 protein, and proteolytic PR3 activity, whereas neutrophil differentiation was not compromised.

Papillon-Lefèvre syndrome with homozygous nonsense mutation of cathepsin C gene presenting with late-onset periodontitis

Papillon-Lefèvre syndrome (PLS) is a rare autosomal recessive disorder of keratinization caused by homozygous mutations in the gene encoding lysosomal protease cathepsin C (CTSC). It is clinically characterized by transgredient palmoplantar keratoderma (PPK) and periodontitis. A 15-year-old boy presenting with PPK from the age of 6 months and late-onset periodontitis that began at the age of 12 years is described. Mutation analysis revealed a homozygous nonsense mutation (p.Y304X) in exon 7 of the CTSC gene. Late-onset periodontitis in a patient with Papillon-Lefèvre syndrome is a rare phenotypic variation.

Serum levels of metal ions in female patients with breast cancer

BACKGROUND

Breast cancer is the second commonest form of cancer among women. Several studies have been conducted to identify potential risk factors. However, role of trace elements or metals in causing breast cancer has not been studied to great extent.

AIMS

To estimate the serum levels of calcium, copper, magnesium, iron, phosphorus and zinc and determine their role in causing breast cancer in female patients.

SETTINGS AND DESIGN

A case-control study on female patients with breast cancer was conducted in a private superspecialty hospital and Cancer centre situated in Southern part of India.

MATERIALS AND METHODS

Newly diagnosed female patients with breast cancer in the age group of 30-60 y attending Oncology clinic were included in the study. These cases were selected irrespective of type and stage of the disease. The age matched control subjects were drawn from apparently healthy women attending master health check at superspecialty hospital. The patients or controls suffering from co-morbid conditions which affect serum levels of metal ions and other malignancies, and those undergoing treatment for breast cancer were excluded from the study. Serum was separated and tests were performed according to standard procedure for each metal ion on the same day. The estimation of metal ions was done by UV-Visible Spectrophotometer-CHEM 7.

STATISTICAL ANALYSIS

Independent Samples T-test was used to calculate difference between the two means. The p-value of <0.05 was considered as significant.

RESULTS

The study was conducted on 54 female patients with breast cancer and 54 female controls with mean age of 47.2±8.14 y and 46.8±8.4 y respectively. There was statistically significant increase in serum levels of calcium, copper, iron and phosphorus in patients with breast cancer when compared to controls. The increase in serum levels of magnesium was insignificant. A statistically significant decrease in serum zinc levels was observed in patient with breast cancer when compared to controls.

CONCLUSION

The present study highlights the role of calcium, copper, iron, phosphorus, magnesium and zinc in the pathogenesis of breast cancer. The estimation of serum levels of these metal ions has a potential role in early detection and monitoring of breast cancer.

A clinical study of 125 patients with phrynoderma

Background:

Phrynoderma is a type of follicular hyperkeratosis. Various nutritional deficiency disorders have been implicated in the etiology of phrynoderma.

Aim:

To determine clinical features of phrynoderma and its association with nutritional deficiency signs.

Materials and Methods:

A cross-sectional descriptive study of 125 consecutive patients with phrynoderma attending the outpatient department (OPD) of dermatology was conducted in a tertiary care hospital. In all patients, a detailed history was taken and cutaneous examination findings such as distribution, sites of involvement, morphology of the lesions, and signs of nutritional deficiencies were noted.

Results:

The proportion of patients with phrynoderma attending the OPD was 0.51%. There were 79 males and 46 females. Age of the patients was in the range of 3-26 years with a mean of 10 ± 4.3 years. The lesions were asymptomatic in 114 (91.2%) patients. The distribution of lesions was bilateral and symmetrical in 89 (71.2%) patients. The disease was localized (elbows, knees, extensor extremities, and/or buttocks) in 106 (84.8%) patients. The site of onset was elbows in 106 (84.8%) patients. The lesions were discrete, keratotic, follicular, pigmented or skin colored, acuminate papules in all patients. Signs of vitamin A and vitamin B-complex deficiency were present in 3.2% and 9.6% patients, respectively. Epidermal hyperkeratosis, follicular hyperkeratosis, and follicular plugging were present in the entire biopsy specimen.

Conclusion:

Phrynoderma is a disorder with distinctive clinical features and can be considered as a multifactorial disease involving multiple nutrients, local factors like pressure and friction, and environmental factors in the setting of increased nutritional demand.

Cutaneous disorders in 500 diabetic patients attending diabetic clinic

Background:

The metabolic complications and pathologic changes that occur in diabetes mellitus (DM) influence the occurrence of various dermatoses.

Aim:

To study the impact of control of diabetes on the pattern of cutaneous disorders.

Materials and Methods:

A cross-sectional descriptive study of patients attending diabetic clinic in a tertiary care hospital. A total of 500 consecutive patients were studied. Detailed history, clinical examination and relevant investigations were done to diagnose diabetic complications and cutaneous disorders. Dermatoses with or without known pathogenesis were correlated with age, gender, fasting plasma glucose (FPG), duration of diabetes, and complications of DM. Statistical analysis was carried out using Student “t” test and Chi-square test with 5% confidence interval (P value 0.05).

Results:

Majority of patients had well-controlled (FPG<130 mg/ml, 60%) type 2 DM (98.8%). No statistically significant difference (P>0.05) between the patients with or without DM specific cutaneous disorders was noticed with reference to age and gender distribution, duration of DM and FPG. Signs of insulin resistance, acrochordon (26.2%), and acanthosis nigricans (5%) were common, followed by fungal (13.8%) and bacterial (6.8%) infections. Eruptive xanthoma (0.6%), diabetic foot (0.2%), diabetic bulla (0.4%), diabetic dermopathy (0.2%), generalized granuloma annulare (0.2%), and insulin reactions (6.2%) and lipodystrophy (14%) were also seen.

Conclusion:

Well-controlled diabetes decreases the prevalence of DM-specific cutaneous disorders associated with chronic hyperglycemia. It is necessary to have a dermatologist in the diabetic clinic for early detection of potentially grave or predisposing conditions.

Actinomycetoma: dramatic response to modified two-step regimen

Mycetoma is a chronic granulomatous infection of the subcutaneous tissue caused by fungi or fungus-like bacteria. The infection eventually spreads to bone resulting in significant morbidity. Rarely, viscera may be involved through contiguous spread. It is common in tropical countries like India, though disease is worldwide in distribution. A 22-year-old male patient, a farmer by occupation, presented with multiple discharging sinuses over the left chest wall, shoulder, upper arm, and adjacent neck of eight months duration. A diagnosis of actinomycetoma was made based on clinical and histopathological features as culture was negative for both fungus and bacteria. The patient was treated with a modified two-step regimen. It consisted of an intensive phase with intravenous gentamicin 80 mg 12th hourly and cotrimoxazole 320/1600 mg twice daily orally for four weeks. This was followed by a maintenance phase with oral cotrimoxazole and doxycycline 100 mg twice daily. Patient showed excellent response with healing of all sinuses after two months of therapy. Involvement of covered parts of the body such as chest wall and shoulders is common in actinomycetoma compared to eumycetoma. Early institution of long-term combination therapy with antimicrobials results in excellent outcome.

Neonatal dermatological emergencies

The neonates are unique in several ways in comparison with older children and adults which render them highly susceptible to severe, sometimes life threatening dermatological disorders. The neonatal dermatological emergencies are a diagnostic and therapeutic challenge. A wide range of dermatoses such as infections, genodermatoses, metabolic disorders and vascular tumors may require emergency care. The clinical presentation also varies from generalized involvement of skin to localized disease with or without systemic symptoms. Irrespective of the etiology and clinical presentation, these disorders are associated with significant morbidity and mortality. With the availability of effective drugs and monitoring facilities, and awareness of need for immediate care, there has been a significant decline in the fatality rate associated with neonatal dermatological emergencies. Knowledge of clinical presentations, rapid diagnostic methods, emergency care and monitoring of progress of the disease helps in comprehensive multidisciplinary care of neonates with these disorders.

Nephrogenic fibrosing dermopathy

An adult female patient on hemodialysis for chronic renal failure presented with large, brownish, and indurated plaques with bound-down skin on both lower limbs and abdomen along with difficulty in movement of the legs. Histopathological features revealed thick collagen bundles admixed with mucin and intercalating spindle-like cells characteristic of nephrogenic fibrosing dermopathy (NFD). Immunohistochemical study showed prominent CD68 positivity and weak CD34 positivity suggesting that the plaques were more than 20-weeks old. NFD in patients with chronic renal failure of unknown cause is a poor prognostic indicator. Early detection before the development of contracture and prompt treatment of NFD and underlying renal failure may reverse this disabling condition.

Finasteride-its impact on sexual function and prostate cancer

Finasteride, a specific and competitive inhibitor of 5alpha-reductase enzyme Type 2, inhibits the conversion of testosterone to dihydrotestosterone (DHT). In adults, DHT acts as primary androgen in prostate and hair follicles. The only FDA-approved dermatological indication of finasteride is androgenetic alopecia. But, apprehension regarding sexual dysfunction associated with finasteride deters dermatologists from prescribing the drug and patients from taking the drug for androgenetic alopecia. Testosterone, through its humoral endocrine and local paracrine effects is relevant in central and peripheral modulation of sexual function than locally acting DHT. Several large population-based long-term placebo-controlled studies, using International Index of Erectile Function-5 questionnaire and objective method (Nocturnal Penile Tumescence) to assess the erectile function have demonstrated no clear evidence of the negative effect of finasteride on erectile function. Reduction in ejaculatory volume is the only established causal relationship between finasteride and sexual dysfunction. Though finasteride causes significant reduction in all the semen parameters except sperm morphology, they did not fall below the threshold levels to interfere with fertility. Therefore, the sexual adverse effects associated with finasteride should be viewed in relation to normal prevalence and natural history of erectile dysfunction in the population, age of the patient, other confounding factors and also nocebo effect. The impact of finasteride on the prevention of prostate cancer has been discussed extensively. Finasteride is found to be effective in significantly reducing the incidence of low-grade prostate cancer. But the paradoxical increase in high-grade cancer in the finasteride group has been attributed to increased sensitivity and improved performance of prostate specific antigen levels to detect all grades of prostate cancer.

Diffuse nonscarring alopecia of scalp: an indicator of early infantile scurvy?

An infant with diffuse nonscarring alopecia of scalp and radiologic features of scurvy responded dramatically to oral vitamin C therapy. The characteristic cutaneous manifestations of scurvy are usually not seen in infancy. The manifestations of initial stage of scurvy that are not related to collagen synthesis, as in the present case, should alert to the possibility of this potentially fatal condition.