[Show abstract][Hide abstract] ABSTRACT: Streptococcus pyogenes (group A streptococcus; GAS) is an etiological agent for pharyngitis, pyoderma, and invasive infections in humans. Pharyngitis and pyoderma may lead to serious immune sequelae such as rheumatic heart disease and post-streptococcal glomerulonephritis (PSGN). Streptococcal Inhibitor of Complement (SIC) and its orthologue, distantly related to SIC (DRS), are virulence factors expressed by only four of more than 100 M types of GAS. These four types (M1, M57, M12 and M55) are among the M types, which are associated with PSGN. In several populations PSGN has been shown to be a risk factor for chronic kidney disease (CKD) and end-stage renal disease (ESRD). Previous studies showed SIC or DRS antibody-prevalence was associated with PSGN, and seroprevalence of SIC antibodies is significantly high among CKD and ESRD patients in Mumbai.
Streptococcal isolates recovered from GAS pyoderma cases were typed. Seropositivity for SIC and DRS antibodies in subjects with pyoderma, PSGN pediatric cases, age matched healthy controls and non-GAS pyoderma cases were determined.
We confirm in this study an association between seroprevalence to SIC and DRS antibodies, and PSGN in Mumbai population despite low point prevalence of M1, M12, M55 and M57. In addition we extended the study to GAS-pyoderma and non-GAS pyoderma cases. To our surprise, we found a positive association between the seroprevalence to SIC and DRS antibodies, and GAS-pyoderma owing to infection with diverse M types. The mechanism of increased predisposition to pyoderma owing to infection by diverse GAS among SIC or DRS antibody-positive population is not clear. Nonetheless, our findings could be explained by a phenomenon akin to antibody-dependent enhancement (ADE).
This is the first report showing a small number of GAS M types conferring predisposition to pyoderma by diverse types. Implications of this ADE-like phenomenon are discussed in the light of evolutionary advantage to GAS, vaccine design and control of renal diseases.
Full-text · Article · Dec 2015 · BMC Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: Xeroderma pigmentosum (XP) is an autosomal recessive genetic disorder characterized by cutaneous and ocular photosensitivity and an increased risk of developing cutaneous neoplasms. Progressive neurological abnormalities develop in a quarter of XP patients.
To study the clinical profile and perform a mutation analysis in Indian patients with xeroderma pigmentosum.
Ten families with 13 patients with XP were referred to our clinic over 2 years. The genes XPA, XPB and XPC were sequentially analyzed till a pathogenic mutation was identified.
Homozygous mutations in the XPA gene were seen in patients with moderate to severe mental retardation (6/10 families) but not in those without neurological features. Two unrelated families with a common family name and belonging to the same community from Maharashtra were found to have an identical mutation in the XPA gene, namely c.335_338delTTATinsCATAAGAAA (p.F112SfsX2). Testing of the XPC gene in two families with four affected children led to the identification of the novel mutations c.1243C>T or p.R415X and c.1677C>A or p.Y559X. In two families, mutations could not be identified in XPA, XPB and XPC genes.
The sample size is small.
Indian patients who have neurological abnormalities associated with XP should be screened for mutations in the XPA gene.
No preview · Article · Jan 2015 · Indian Journal of Dermatology Venereology and Leprology
[Show abstract][Hide abstract] ABSTRACT: Background:
Early lesions of vitiligo can be confused with various other causes of hypopigmentation and depigmentation. Few workers have utilized dermoscopy for the diagnosis of evolving lesions of vitiligo.
To analyze the dermoscopic findings of evolving lesions in diagnosed cases of vitiligo and to correlate them histopathologically.
Dermoscopy of evolving lesions in 30 diagnosed cases of vitiligo was performed using both polarized light and ultraviolet light.
On polarized light examination, the pigmentary network was found to be reduced in 12 (40%) of 30 patients, absent in 9 (30%), and reversed in 6 (20%) patients; 2 patients (6.7%) showed perifollicular hyperpigmentation and 1 (3.3%) had perilesional hyperpigmentation. A diffuse white glow was demonstrable in 27 (90%) of 30 patients on ultraviolet light examination. Melanocytes were either reduced in number or absent in 12 (40%) of 30 patients on histopathology.
Pigmentary network changes, and perifollicular and perilesional hyperpigmentation on polarized light examination, and a diffuse white glow on ultraviolet light examination were noted in evolving vitiligo lesions. Histopathological examination was comparatively less reliable. Dermoscopy appears to be better than routine histopathology in the diagnosis of evolving lesions of vitiligo and can obviate the need for a skin biopsy.
No preview · Article · Nov 2014 · Indian Journal of Dermatology Venereology and Leprology
[Show abstract][Hide abstract] ABSTRACT: Chanarin-Dorfman syndrome (CDS) is a multisystem, autosomal recessive genetic disorder characterized by congenital non-bullous ichthyosiform erythroderma with accumulation of lipid droplets in granulocytes and basal keratinocytes. An 18-month-old female child presented with typical dermatological features of CDS. She was born as a collodion baby. Liver biopsy showed micronodular cirrhosis along with macrovesicular hepatic steatosis. Sequencing of all exons and exon-intron boundaries of the ABHD5 gene showed that the patient was homozygous for a novel mutation g.24947delG (c.773 + 1delG) in intron 5. This is the first Indian child with mutation proven CDS.
No preview · Article · Jul 2014 · Journal of Postgraduate Medicine
[Show abstract][Hide abstract] ABSTRACT: Background:
Palmoplantar lesions in lichen planus (LP) are uncommon. In such cases, diagnosis is usually missed. This study was conducted to document various clinical and histopathological features of palmoplantar LP.
Materials And Methods:
A total of 18 patients from our outpatient department with lesions of LP, either predominantly or exclusively on palms and/or soles were studied. Patients with history of drug intake in recent past and patients with classical acute widespread LP with a few lesions on palms or soles were excluded. In each patient, diagnosis was made on clinicopathological correlation. Various clinical and histopathological features were analyzed.
Average age of onset was 38 years. Male: female ratio was 1:0.6 and average disease duration was 11 months. Exclusive palm or sole involvement was seen in 4/18 patients. Itching was the most common symptom. Clinically the most common variant was hypertrophic. Histologically presence of parakeratosis, spongiosis, lack of melanophages, and lack of hypergranulosis in some cases was seen in addition to classical features of LP. In 3 out of 4 patients with exclusive palmoplantar involvement diagnosis of LP was missed clinically.
Involvement of palms and soles in LP poses a diagnostic challenge due to variable presentations. Histopathology is of vital importance for correct diagnosis and treatment.
No preview · Article · Jul 2014 · Indian Journal of Dermatology
[Show abstract][Hide abstract] ABSTRACT: Background: Rituximab, a monoclonal anti-CD20 antibody, has been used with encouraging results in pemphigus. We describe herein refractory cases of pemphigus vulgaris (n = 23) and pemphigus foliaceus (n = 1) treated with rituximab in addition to steroids and immunosuppressants. Aims: To assess the response to treatment, the duration of clinical remission, serology of the response and adverse effects of rituximab in pemphigus patients. Methods: We recorded observations of 24 patients with pemphigus having either refractory disease in spite of high dose of steroids and immunosuppressants, corticosteroid-dependent disease, strong contraindications to corticosteroids, or severe disease. The patients were treated with infusions of one injection per week for three consecutive weeks of 375 mg of rituximab per m 2 of body-surface area. One similar infusion was repeated after 3 months of 3 rd dose. We observed the clinical outcome after 6 months of 3 rd dose of rituximab and looked for complete healing of cutaneous and mucosal lesions (complete remission). Observations: After follow-up of 7-24 months, five patients showed only partial improvement while 19 of 24 patients had a complete remission 3 months after rituximab. Of these 19 patients, 12 patients achieved complete remission and are off all systemic therapy, and the rest are continuing with no or low dose of steroids with immunosuppressants. Two patients relapsed after initial improvement; one was given moderate dose of oral steroids and immunosuppressant and the other was given repeat single dose of rituximab to control relapse. Conclusion: Rituximab is able to induce a prolonged clinical remission in pemphigus after a single course of four infusions. The high cost and limited knowledge of long term adverse effects are limitations to the use of this biologic agent.
No preview · Article · Jul 2014 · Indian Journal of Dermatology Venereology and Leprology