Endocrine dysfunction in leprosy

Changes in plasma levels of endocrine hormones in lepromatous leprosy patients

Background

Leprosy affects various endocrine glands and causes disorders in internal organs in addition to the skin and peripheral nerves. These disorders are often silent and remain undiagnosed or underreported. In particular, patterns of hormone changes during leprosy, especially in lepromatous leprosy (LL) patients, are often associated with dysregulation of different endocrine and sex hormones. The aim of this study was to assess changes in four endocrine hormones - namely cortisol, dehydroepiandrosterone (DHEA), growth hormone (GH), and leptin - among LL patients compared with apparently healthy controls.

Method

In total, 80 plasma samples were systematically retrieved from a biorepository at the Armauer Hansen Research Institute (AHRI), based on quality, adequacy of sample volume, and appropriateness of linked clinical and sociodemographic data. Forty of the samples were obtained from LL patients (cases) and the remaining 40 from apparently healthy controls. Enzyme-linked immunosorbant assay (ELISA) was used to quantify levels of DHEA, cortisol, GH, and leptin hormones in the plasma samples. Data were analyzed using non-parametric statistics and the Mann-Whitney U-test (GraphPad Prism version 7.01). A p-value < 0.05 was considered statistically significant.

Results

Plasma levels of cortisol concentration were significantly higher in LL cases (median = 111.4 ng/ml, range = 20.54-525.7) compared with healthy controls (median = 51.98 ng/ml, range = 3.805-328.4) (p = 0.003). Levels of GH and leptin were significantly lower in LL cases compared with healthy controls (median values for GH = 1.01 µIU/ml, range = 0.4625-86.82 and 2 µIU/ml, range = 0.5838-63.36, respectively (p = 0.022); median values for leptin = 891 pg/ml, range = 728.4-21816 and 5147 pg/ml, range = 730.4-52747, respectively (p < 0.0001)). There was an apparent reduction in the plasma levels of DHEA among LL cases compared with healthy controls (p = 0.297), although this difference was not statistically significant.

Conclusion

Alterations in levels of endocrine hormones seen in LL patients reflect clinical and immunological conditions during lepromatous leprosy. However, large-scale studies are warranted to determine how leprosy causes such alterations in hormones and the interplay between endocrine hormones and the immune system during leprosy disease.

Genome-wide association study of leprosy in Malawi and Mali

Leprosy is a chronic infection of the skin and peripheral nerves caused by Mycobacterium leprae. Despite recent improvements in disease control, leprosy remains an important cause of infectious disability globally. Large-scale genetic association studies in Chinese, Vietnamese and Indian populations have identified over 30 susceptibility loci for leprosy. There is a significant burden of leprosy in Africa, however it is uncertain whether the findings of published genetic association studies are generalizable to African populations. To address this, we conducted a genome-wide association study (GWAS) of leprosy in Malawian (327 cases, 436 controls) and Malian (247 cases, 368 controls) individuals. In that analysis, we replicated four risk loci previously reported in China, Vietnam and India; MHC Class I and II, LACC1 and SLC29A3. We further identified a novel leprosy susceptibility locus at 10q24 (rs2015583; combined p = 8.81 × 10-9; OR = 0.51 [95% CI 0.40 - 0.64]). Using publicly-available data we characterise regulatory activity at this locus, identifying ACTR1A as a candidate mediator of leprosy risk. This locus shows evidence of recent positive selection and demonstrates pleiotropy with established risk loci for inflammatory bowel disease and childhood-onset asthma. A shared genetic architecture for leprosy and inflammatory bowel disease has been previously described. We expand on this, strengthening the hypothesis that selection pressure driven by leprosy has shaped the evolution of autoimmune and atopic disease in modern populations. More broadly, our data highlights the importance of defining the genetic architecture of disease across genetically diverse populations, and that disease insights derived from GWAS in one population may not translate to all affected populations.

Ancient DNA study reveals HLA susceptibility locus for leprosy in medieval Europeans

Leprosy, a chronic infectious disease caused by Mycobacterium leprae (M. leprae), was very common in Europe till the 16th century. Here, we perform an ancient DNA study on medieval skeletons from Denmark that show lesions specific for lepromatous leprosy (LL). First, we test the remains for M. leprae DNA to confirm the infection status of the individuals and to assess the bacterial diversity. We assemble 10 complete M. leprae genomes that all differ from each other. Second, we evaluate whether the human leukocyte antigen allele DRB1*15:01, a strong LL susceptibility factor in modern populations, also predisposed medieval Europeans to the disease. The comparison of genotype data from 69 M. leprae DNA-positive LL cases with those from contemporary and medieval controls reveals a statistically significant association in both instances. In addition, we observe that DRB1*15:01 co-occurs with DQB1*06:02 on a haplotype that is a strong risk factor for inflammatory diseases today.

Leprosy, caused by infection with Mycobacterium leprae, was common in Europe in the Middle Ages. Here, Krause-Kyora et al. analyze ancient DNA from a medieval Danish leprosarium to assemble 10 complete bacterial genomes and perform association analysis of the DRB1*15:01 allele with risk of leprosy infection.

Endocrine dysfunction in patients of leprosy

BACKGROUND

Leprosy is a chronic granulomatous disease and affects many internal organs in addition to the skin and peripheral nerves. Endocrine dysfunction is often silent and is often missed in patients of leprosy leading to significant morbidity. We studied the presence of occult endocrine disorders in leprosy patients and compared the same with disease parameters.

MATERIALS AND METHODS

We evaluated 40 patients of leprosy (aged 18-70 years, any duration) in this cross-sectional, observational study. All subjects were assessed for pituitary, thyroid, adrenal, gonadal function, and dynamic testing was done when deemed necessary. The participants were divided into two groups: Group 1 (Leprosy, n = 40) and Group 2 (Controls, n = 20) and the data were analyzed with appropriate statistical tests.

RESULTS

The study participants (35 males, 5 females) had a mean age of 36.4 ± 11.3 years, and duration of the disease was 2.5 ± 5.5 years. Eleven out of 40 patients showed results consistent with an endocrine disorder, including subclinical hypothyroidism (n = 4), sick euthyroid syndrome (n = 3), growth hormone (GH) deficiency (n = 2), primary hypogonadism (n = 2) and secondary hypogonadism in one patient. One patient had partial hypopituitarism (GH deficiency and secondary hypogonadism) and none of the controls showed any hormonal dysfunction. Testosterone levels showed inverse correlation with the number of skin patches (P = 0.0006).

CONCLUSION

Occult endocrine dysfunction is seen in a quarter of patients with leprosy. Thyroid and gonadal axes abnormalities are common, and the severity is more in lepromatous forms of the disease. Further large studies are required to confirm the findings observed in our study.

Risk factors for leprosy reactions in three endemic countries

The objective of this study was to ascertain risk factors for complications (reactions or neuritis) in leprosy patients at the time of diagnosis in three leprosy-endemic countries. Newly diagnosed patients were enrolled in Brazil, the Philippines, and Nepal, and risk factors for reactions and neuritis were assessed using a case-control approach: "cases" were patients with these complications, and controls were patients without complications. Of 1,972 patients enrolled in this study, 22% had complications before treatment. Type 1 reaction was diagnosed in 13.7% of patients, neuritis alone in 6.9.%, and type 2 reaction in 1.4%. The frequency of these complications was higher in Nepal, in lepromatous patients, in males, and in adults versus children. Reactions and neuritis were seen in patients at diagnosis, before treatment was started. Reactions were seen in adults and children, even in patients with only a single lesion. Neuritis was often present without other signs of reaction. Reactions and neuritis were more likely to occur in lepromatous patients, and were more likely to be seen in adults than in children.

Menstrual irregularities, fertility status, and ovarian function in female patients with leprosy in India

BACKGROUND

Gonadal involvement in males in lepromatous leprosy is not uncommon, but there is a paucity of literature on the involvement of gonads in female patients with leprosy. This study was undertaken to determine if there is any menstrual dysfunction, alteration in fertility status and circulating luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, and estradiol in female patients with paucibacillary (PB) and multibacillary (MB) leprosy.

MATERIALS AND METHODS

In a cross-sectional study, 229 patients with leprosy (79 with PB leprosy and 150 with MB leprosy) and 100 age-matched non-leprosy controls were evaluated for menstrual function, fertility status, and circulating sex hormones.

RESULTS

Twenty percent of patients with MB leprosy had menstrual irregularities post-dating the onset of leprosy in comparison to 6.3% patients with PB leprosy, and this difference was statistically significant (P < 0.001). However, the fertility profile of patients with PB leprosy was comparable to that of patients with MB leprosy (P > 0.05). A significantly higher number of patients with MB leprosy (9.3%) had elevation of circulating FSH, LH, and prolactin vis-à-vis patients with PB leprosy (1.3%), and this difference was statistically significant (P < 0.05). Similarly, the mean levels of LH, FSH, and prolactin were significantly elevated in patients with MB leprosy vis-à-vis patients with PB leprosy and controls (P < 0.05).

CONCLUSIONS

Multibacillary leprosy may be associated with menstrual irregularities and elevation of gonadotropin hormones, indicating an ovarian dysfunction.

The clinical & neurophysiological study of leprosy

OBJECTIVES

The aim of this study was to evaluate neurological and neurophysiological features of leprosy.

METHODS

Seventy seven hospitalized leprosy patients (52 male, 25 female) were examined neurological and neurophysiologically between 2010 and 2012. Standard procedures were performed for evaluating sensory and motor conduction studies to all patients. Motor studies were carried out on median, ulnar, tibial and common peroneal nerves. Sensory studies were carried out on median, ulnar and sural nerves. Sympathetic skin response (SSR) recordings on both hands and feet, and the heart rate (R-R) interval variation (RRIV) recordings on precordial region were done in order to evaluate the autonomic dysfunction.

RESULTS

The mean age was 59.11±14.95 years ranging between 17 and 80 years. The mean duration of disease was 35.58±18.30 years. Clinically, the patients had severe deformity and disability. In neurophysiological examinations, sensory, motor conduction studies of the lower extremities were found to be more severely affected than upper, and sensory impairment predominated over motor. Abnormal SSRs were recorded in 63 (81.8%) cases of leprosy. Abnormal RRIVs were recorded in 41 (53.2%) cases and abnormal RRIVs with hyperventilation were recorded in 55 (71.4%) cases of leprosy. Significant differences were found between SSR and sensory conduction parameters of median, ulnar nerves as well as motor conduction parameters of median, ulnar and peroneal nerves (p<0.05).

CONCLUSION

Peripheral nervous system dysfunction is accompanied by autonomic nervous system dysfunction in leprosy patients. Sympathetic involvement may predominate over parasympathetic involvement.

Natural selection and infectious disease in human populations

Infectious pathogens are among the strongest selective forces that shape the human genome. Migrations and cultural changes in the past 100,000 years exposed populations to dangerous new pathogens.

Host genetics influences susceptibility to infectious disease. Evolutionary adaptations for resistance and symbiosis may underlie common immune-mediated diseases.

Signatures of selection and methods to detect them vary with the age, geographical spread and virulence of the pathogen.

A history of selection on a trait adds power to association studies by driving the emergence of common alleles of strong effect. Combining selection and association metrics can further increase power.

Genome-wide association studies (GWASs) of susceptibility to pathogens that are moderately old (1,000–50,000 years ago), geographically limited in history and exerted strong positive selective pressure will have the most power if GWASs can be done in the historically affected population.

An understanding of host–pathogen interactions can inform the development of new therapies for both infectious diseases and common immune-mediated diseases.

The impact of various infectious agents on human survival and reproduction over thousands of years has exerted selective pressure on numerous regions of the human genome. This Review describes how such signatures of selection can be detected and integrated with data from complementary approaches, such as genome-wide association studies, to provide biological insights into host–pathogen interactions.

The ancient biological 'arms race' between microbial pathogens and humans has shaped genetic variation in modern populations, and this has important implications for the growing field of medical genomics. As humans migrated throughout the world, populations encountered distinct pathogens, and natural selection increased the prevalence of alleles that are advantageous in the new ecosystems in both host and pathogens. This ancient history now influences human infectious disease susceptibility and microbiome homeostasis, and contributes to common diseases that show geographical disparities, such as autoimmune and metabolic disorders. Using new high-throughput technologies, analytical methods and expanding public data resources, the investigation of natural selection is leading to new insights into the function and dysfunction of human biology.

Diabetic status of patients with leprosy in Kuwait

OBJECTIVE

The aim of this study was to screen for diabetes mellitus in leprosy patients to elucidate whether leprosy infection may play a role in the pathogenesis of diabetes mellitus in this population.

SUBJECTS AND METHODS

Thirty patients of different ages and of both sexes with various types of leprosy were included in this study. In addition, 15 healthy individuals of comparable age and sex who had no family history of diabetes mellitus were identified as controls. In both groups, determinations of fasting and postprandial blood sugar, an oral glucose tolerance test (OGTT), measures of fasting serum insulin and pro-inflammatory cytokine tumor necrosis factor alpha (TNFα), as well as calculations using the Homeostasis Model Assessment for Insulin Resistance (HOMA-IR), were carried out.

RESULT

Approximately 13.3% of the leprosy patients were diabetic, and 37.7% were in pre-diabetic. The highest incidences of diabetes and pre-diabetes were in lepromatous leprosy (10% and 20%, respectively); a lower incidence of pre-diabetes (6.6%) was observed in tuberculoid leprosy; and the lowest incidence of diabetes (0.0%) was noted in borderline leprosy patients. Although normal healthy persons were not diabetic (0%), 20% were pre-diabetic.

CONCLUSION

This study revealed that the incidence of diabetes was higher in the leprosy patients than in the control group. As a result, we recommend that all leprosy patients should be screened for diabetes.

Circulating levels of insulin-like growth factor-I (IGF-I) correlate with disease status in leprosy

BACKGROUND

Caused by Mycobacterium leprae (ML), leprosy presents a strong immune-inflammatory component, whose status dictates both the clinical form of the disease and the occurrence of reactional episodes. Evidence has shown that, during the immune-inflammatory response to infection, the growth hormone/insulin-like growth factor-I (GH/IGF-I) plays a prominent regulatory role. However, in leprosy, little, if anything, is known about the interaction between the immune and neuroendocrine systems.

METHODS

In the present retrospective study, we measured the serum levels of IGF-I and IGBP-3, its major binding protein. These measurements were taken at diagnosis in nonreactional borderline tuberculoid (NR BT), borderline lepromatous (NR BL), and lepromatous (NR LL) leprosy patients in addition to healthy controls (HC). LL and BL patients who developed reaction during the course of the disease were also included in the study. The serum levels of IGF-I, IGFBP-3 and tumor necrosis factor-alpha (TNF-α) were evaluated at diagnosis and during development of reversal (RR) or erythema nodosum leprosum (ENL) reaction by the solid phase, enzyme-labeled, chemiluminescent-immunometric method.

RESULTS

The circulating IGF-I/IGFBP-3 levels showed significant differences according to disease status and occurrence of reactional episodes. At the time of leprosy diagnosis, significantly lower levels of circulating IGF-I/IGFBP-3 were found in NR BL and NR LL patients in contrast to NR BT patients and HCs. However, after treatment, serum IGF-I levels in BL/LL patients returned to normal. Notably, the levels of circulating IGF-I at diagnosis were low in 75% of patients who did not undergo ENL during treatment (NR LL patients) in opposition to the normal levels observed in those who suffered ENL during treatment (R LL patients). Nonetheless, during ENL episodes, the levels observed in RLL sera tended to decrease, attaining similar levels to those found in NR LL patients. Interestingly, IGF-I behaved contrary to what was observed during RR episodes in R BL patients.

CONCLUSIONS

Our data revealed important alterations in the IGF system in relation to the status of the host immune-inflammatory response to ML while at the same time pointing to the circulating IGF-I/IGFBP-3 levels as possible predictive biomarkers for ENL in LL patients at diagnosis.

Recent advances in leprosy and Buruli ulcer (Mycobacterium ulcerans infection)

PURPOSE OF REVIEW

After tuberculosis, leprosy (Mycobacterium leprae) and Buruli ulcer (M. ulcerans infection) are the second and third most common mycobacterial infections in humankind, respectively. Recent advances in both diseases are summarized.

RECENT FINDINGS

Leprosy remains a public health problem in some countries, and new case detections indicate active transmission. Newly identified M. lepromatosis, closely related to M. leprae, may cause disseminated leprosy in some regions. In genome-wide screening in China, leprosy susceptibility associates with polymorphisms in seven genes, many involved with innate immunity. World Health Organization multiple drug therapy administered for 1 or 2 years effectively arrests disseminated leprosy but disability remains a public health concern. Relapse is infrequent, often associated with higher pretreatment M. leprae burdens. M. ulcerans, a re-emerging environmental organism, arose from M. marinum and acquired a virulence plasmid coding for mycolactone, a necrotizing, immunosuppressive toxin. Geographically, there are multiple strains of M. ulcerans, with variable pathogenicity and immunogenicity. Molecular epidemiology is describing M. ulcerans evolution and genotypic variants. First-line therapy for Buruli ulcer is rifampin + streptomycin, sometimes with surgery, but improved regimens are needed.

SUMMARY

Leprosy and Buruli ulcer are important infections with significant public health implications. Modern research is providing new insights into molecular epidemiology and pathogenesis, boding well for improved control strategies.

Management of osteoporosis in the aging male: focus on zoledronic acid

Osteoporosis in the aging male remains an important yet under-recognized and undertreated disease. Current US estimates indicate that over 14 million men have osteoporosis or low bone mass, and men suffer approximately 500,000 osteoporotic fractures each year. Men experience fewer osteoporotic fractures than women but have higher mortality after fracture. Bisphosphonates are potent antiresorptive agents that inhibit osteoclast activity, suppress in vivo markers of bone turnover, increase bone mineral density, decrease fractures, and improve survival in men with osteoporosis. Intravenous zoledronic acid may be a preferable alternative to oral bisphosphonate therapy in patients with cognitive dysfunction, the inability to sit upright, or significant gastrointestinal pathology. Zoledronic acid (Reclast) is approved in the US as an annual 5 mg intravenous infusion to treat osteoporosis in men. The zoledronic acid (Zometa) 4 mg intravenous dose has been studied in the prevention of bone loss associated with androgen deprivation therapy.