Unusual Cortical Phenotype After Hematopoietic Stem Cell Transplantation in a Patient With Osteopetrosis.

The osteopetroses are a group of rare genetic diseases caused by osteoclast dysfunction or absence. The hallmark of osteopetrosis is generalized increased bone mineral density (BMD). However, the bone is fragile and fractures are common. Autosomal recessive osteopetrosis is usually a severe disorder and often life-threatening in childhood. We present male siblings with autosomal recessive osteopetrosis due to biallelic variants in TCIRG1 who survived childhood and underwent hematopoietic stem cell transplant (HSCT) in adulthood. One sibling died of posttransplant complications. After transplant, the other sibling had improvement of multiple clinical parameters, including some decline in BMD Z-scores by dual-energy X-ray absorptiometry (DXA) and cessation of fractures. However, spine quantitative computed tomography 11 years after transplant demonstrated an anvil pattern of sclerosis with BMD Z-score of +18.3. High-resolution peripheral quantitative computed tomography (HR-pQCT) of the tibia demonstrated near complete obliteration of the marrow space combined with an unusual cortical phenotype, suggesting extensive cortical porosity at the distal tibia. This case highlights that despite successful transplantation and subsequent improvement in clinical parameters, this patient continued to have significantly elevated bone density and decreased marrow space. Transplant-associated increased cortical porosity is multifactorial and occurs in two-thirds of non-osteopetrotic patients undergoing HSCT. This finding after transplant in osteopetrosis may suggest particular sensitivity of the cortical bone to resorptive activity of transplanted osteoclasts. The case also suggests HR-pQCT may be a useful modality for imaging and assessing the therapeutic effects on bone in individuals with osteopetrosis. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Malignant Hypertension in Association with Low Estrogen Dose Oral Contraceptives: Case Report and Review of Literature.

Malignant hypertension (MH) has been described in association with high-dose (50 - 100 mcg) estrogen oral contraceptive pills (OCPs). Although the rise in blood pressure (BP) is usually mild, some women will have a more significant increase in BP, and hypertensive emergencies may very rarely occur. We present a 21-year-old Caucasian female with a past medical history of fibromyalgia and family history of hypertension (both grandparents) who was admitted with a three-day history of headache and blurring of vision in her left eye with a BP of 210/150. Her medications, which were continued on admission, included tramadol, 100 mg twice daily (bid), and low-dose estrogen OCP. During the hospital course, she received different antihypertensive medications and her hypertension was controlled. A diagnosis of MH due to OCP was made. All antihypertensive medications were stopped, except metoprolol, and the patient was discharged home on metoprolol with a BP of 107/55 mmHg. On follow-up in the medical clinic three months later, her visual disturbances had completely resolved and her BP was 98/56 mmHg.  One-third of patients aged 15 - 44 years old who develop MH are likely to be on high-dose estrogen OCP. As far as we know, our case is the third documented case of MH occurring in patients on low-dose estrogen OCP. Chronic use of oral contraceptives will slightly increase the systemic BP in most women. It is advisable to avoid OCP in high-risk patients and do regular BP checks on patients on OCP. In patients presenting with hypertension or MH while on OCP, the OCP should be discontinued.

Effect of High-dose Biotin on Thyroid Function Tests: Case Report and Literature Review.

Biotin is a readily available supplement that is part of the B-complex vitamins. It is an essential co-factor for five carboxylases involved in fatty acid synthesis and energy production. The recommended daily intake (RDI) of biotin ranges from 30 to 70 mcg per day. At high doses (10,000 times RDI), biotin improves clinical outcomes and quality of life in patients with progressive multiple sclerosis (MS). It has been reported to cause interference in immunoassays resulting in abnormal thyroid function tests. Hereby we are describing the case of a patient having MS who was on high-dose biotin, seen in the clinic for a follow-up visit with thyroid function tests suggestive of Graves' disease with no signs and symptoms of hyperthyroidism and completely normal physical examination. In the case we have described, the laboratory measurements suggestive of thyrotoxicosis were attributed to interference of the patient's high-dose biotin treatment with the biotin-streptavidin chemistry of the immunoassays. We observed normalization of the thyroid stimulating hormone (TSH) and free T4 measurements when the patient withheld biotin for a week. As our case illustrates, early consideration of biotin interference minimizes unnecessary repeat laboratory studies. As trials in MS are progressing, we expect to see more patients on high-dose biotin treatment with spurious laboratory measurements. Therefore, we advise careful history taking and close communication with the laboratory when the clinical picture does not match with the laboratory results.