Hair microscopy: an easy adjunct to diagnosis of systemic diseases in children

Chedíak-Higashi Syndrome: Hair-to-toe spectrum

Chedíak-Higashi Syndrome (CHS) is a rare autosomal recessive disorder caused by mutations in the Lysosomal Trafficking Regulator (LYST) gene, leading to defective lysosomal function in immune cells, melanocytes, and neurons. Clinically, CHS is characterized by a spectrum of symptoms, including immunodeficiency, partial oculocutaneous albinism, bleeding tendencies, neurodevelopmental deficits and progressive neurodegenerative symptoms. The severity of CHS correlates with the type of LYST mutation: the classic form, linked to nonsense or frameshift mutations, presents early in childhood with severe immune dysfunction, recurrent infections, and a high risk of hemophagocytic lymphohistiocytosis (HLH), a life-threatening hyperinflammatory state. Without timely treatment, including hematopoietic stem cell transplantation (HSCT), prognosis is poor, with high mortality in early life. Atypical forms, associated with missense mutations, manifest later with milder immunologic symptoms but inevitably progress to neurological impairment, including cognitive decline and motor dysfunction. Diagnosing CHS is complex due to its rarity, phenotypic variability, and overlap with other disorders. A thorough approach, incorporating clinical evaluation, peripheral blood smear for giant granules in leukocytes, and genetic testing for LYST mutations, is crucial for accurate diagnosis. Management of CHS requires a multidisciplinary approach, focusing on HSCT for immunologic and hematologic stabilization and symptomatic and supportive care for neurological symptoms. Even those patients who undergo stabilizing HSCT eventually develop neurological difficulties. This review provides an in-depth exploration of CHS, covering its epidemiology, clinical presentation, molecular genetics, diagnostic challenges, and current management strategies, while emphasizing the necessity of a comprehensive, multidisciplinary approach to improve patient outcomes.

Early diagnosis of immunodeficient patients with partial albinism: The role of hair study and peripheral blood smear

BACKGROUND

Primary immunodeficiency diseases (inborn errors of immunity) with partial albinism are a group of autosomal recessive syndromes including Chediak Higashi Syndrome (CHS), Griscelli Syndrome type 2 (GS2), Hermansky-Pudlak Syndromes type 2 and 10 (HPS2, HPS10), Vici syndrome and P14/LAMTOR2 deficiency.

METHODS

Twenty-five patients including 10 CHS, 10 GS2, and 5 HPS2 were evaluated in this study within the last 10 years. Five cases with oculocutaneous albinism (OCA) and 5 healthy subjects without albinism were used as two control groups. Genetic analyses were performed by whole exome or panel sequencing or targeted Sanger sequencing. Subsequently, leukocyte granules in peripheral blood smear and hair shaft were examined as screening tests.

RESULTS

Giant granules were only presented in the leukocytes cytoplasm of 10/10 CHS patients. The uneven cluster of pigments and giant melanin granules in hair samples were observed in 10/10 GS2 and 10/10 CHS patients, respectively. In both 5/5 OCA and 5/5 HPS2 patients, there were regular pigments in the middle of hair shafts. Genetic analyses were performed for all patients, revealing 7 novel variants in LYST gene for CHS patients and 4 novel variants in AP3B1 for HPS2 patients.

CONCLUSION

Receiving hematopoietic stem cell transplantation (HSCT) in a timely manner is crucial in CHS and GS2 patients; therefore, screening tests may provide a vital clue for early diagnosis in these patients. However, the final confirmation of CHS, GS2, and HPS2 disorders is done by genetic assay.

Linear hair growth rates in preschool children

BACKGROUND

Human scalp hair is a validated bio-substrate for monitoring various exposures in childhood including contextual stressors, environmental toxins, prescription or non-prescription drugs. Linear hair growth rates (HGR) are required to accurately interpret hair biomarker concentrations.

METHODS

We measured HGR in a prospective cohort of preschool children (N = 266) aged 9-72 months and assessed demographic factors, anthropometrics, and hair protein content (HPC). We examined HGR differences by age, sex, race, height, hair pigment, and season, and used univariable and multivariable linear regression models to identify HGR-related factors.

RESULTS

Infants below 1 year (288 ± 61 μm/day) had slower HGR than children aged 2-5 years (p = 0.0073). Dark-haired children (352 ± 52 μm/day) had higher HGR than light-haired children (325 ± 50 μm/day; p = 0.0019). Asian subjects had the highest HGR overall (p = 0.016). Younger children had higher HPC (p = 0.0014) and their HPC-adjusted HGRs were slower than older children (p = 0.0073). Age, height, hair pigmentation, and HPC were related to HGR in multivariable regression models.

CONCLUSIONS

We identified age, height, hair pigment, and hair protein concentration as significant determinants of linear HGRs. These findings help explain the known hair biomarker differences between children and adults and aid accurate interpretation of hair biomarker results in preschool children.

IMPACT

Discovery of hair biomarkers in the past few decades has transformed scientific disciplines like toxicology, pharmacology, epidemiology, forensics, healthcare, and developmental psychology. Identifying determinants of hair growth in children is essential for accurate interpretation of hair biomarker results in pediatric clinical studies. Childhood hair growth rates define the time-periods of biomarker incorporation into growing hair, essential for interpreting the biomarkers associated with environmental exposures and the mind-brain-body connectome. Our study describes age-, sex-, and height-based distributions of linear hair growth rates and provides determinants of linear hair growth rates in a large population of children. Age, height, hair pigmentation, and hair protein content are determinants of hair growth rates and should be accounted for in child hair biomarkers studies. Our findings on hair protein content and linear hair growth rates may provide physiological explanations for differences in hair growth rates and biomarkers in preschool children as compared to adults.

CBD: A Potential Lead against Hair Loss, Alopecia, and its Potential Mechanisms

BACKGROUND

Nowadays, the majority of the population suffers from the problem of hair loss. It leads to disturbed mental health, lower self-confidence, and a lot more problems. A lot of the hair loss therapies available are not reliable and lead to recurrence and side effects after some time. Cannabinoids (CBD) have recently become quite popular for their benefits against hair loss. CBD oil preparations have been used both internally and externally for oral and topical use, respectively. Due to the presence of the endocannabinoid system (ECS) in the body, which naturally targets CB1 and CB2 receptors, the control of hair fall is possible. CBD is used topically for hair loss, whereas it is administered orally for the treatment and management of a medical condition, i.e., alopecia.

AIM/OBJECTIVE

The present review aimed to provide an in-depth study on hair loss and its management using CBD and its associated mechanisms.

METHODS

Electronic databases, such as ScienceDirect, Google Scholar, PubMed, Wiley, Springer, and Scopus, were thoroughly searched for information about how CBD is used, how it works, and what role it plays in treating alopecia and hair loss.

RESULTS

This review has highlighted the use of CBD-based hair loss therapy, and described various types of hair loss and their treatments. This review also details the phytocannabinoids and the potential mechanisms of CBD's activity against hair loss and alopecia.

CONCLUSION

The data obtained from the literature regarding CBD and hair loss provide a scientific basis for CBD use in alopecia. Additionally, a more precise and comprehensive study concerning CBD needs to be carried out at the pre-clinical and clinical levels.

Non-Invasive Techniques for Evaluating Alopecia Areata

Alopecia areata (AA) is a disease affecting mostly young patients, being the second most prevalent cause of alopecia. For the assessment of AA patients, numerous non-invasive techniques are available. For diagnosing and treating AA, non-invasive hair follicle exploration is crucial. Trichoscopy, videodermoscopy, pull test, global scalp photography and scalp imaging techniques (reflectance confocal microscopy (RCM), multiphoton microscopy (MPM), and high-frequency ultrasonography (HF-USG) are non-invasive methods used to assess the hair loss. Short vellus hairs and yellow dots were the most commonly reported and sensitive trichoscopy signs of AA. Additionally, it was observed that AA activity was associated with black dots, micro-exclamation mark hairs and tapering hairs. A good prognosis of AA includes the transformation of vellus into terminal hairs. Reflectance confocal microscopy is a non-invasive imaging technique for in vivo evaluation of the skin and observation of cell morphology with a nearly histological resolution, which is helpful in diagnosis and management of AA. Additionally, MPM delivers information on hair follicles and scalp inflammation and can be utilized to assess hair growth while undergoing treatment. High-frequency ultrasonography allows distinguishing between hair cycle phases, which is undoubtedly important from the prognostic of AA. The current review aims to discuss the non-invasive methods of diagnosis of AA.