Pathogenesis of Metastatic Calcification and Acute Pancreatitis in Adult T-Cell Leukemia under Hypercalcemic State

Generalized Arterial Calcification of Infancy (GACI): Optimizing Care with a Multidisciplinary Approach

It is very unusual to see evidence of arterial calcification in infants and children, and when detected, genetic disorders of calcium metabolism should be suspected. Generalized arterial calcification of infancy (GACI) is a hereditary disease, which is characterized by severe arterial calcification of medium sized arteries, mostly involving the media with marked intimal proliferation and ectopic mineralization of the extravascular tissues. It is caused by inactivating variants in genes encoding either ENPP1, in a majority of cases (70–75%), or ABCC6, in a minority (9–10%). Despite similar histologic appearances between ENPP1 and ABCC6 deficiencies, including arterial calcification, organ calcification, and cardiovascular calcification, mortality is higher in subjects carrying the ENPP1 versus ABCC6 variants (40% vs 10%, respectively). Overall mortality in individuals with GACI is high (55%) before the age of 6 months, with 24.4% dying in utero or being stillborn. Rare cases show spontaneous regression with age, while others who survive into adulthood often manifest musculoskeletal complications (osteoarthritis and interosseous membrane ossification), enthesis mineralization, and cervical spine fusion. Despite recent advances in the understanding of the genetic mechanisms underlying this disease, there is still no ideal therapy for the resolution of vascular calcification in GACI. Although bisphosphonates with anti-calcification properties have been commonly used for the treatment of CAGI, their benefit is controversial, with favorable results reported at one year and questionable benefit with delayed initiation of treatment. Enzyme replacement therapy with administration of recombinant form of ENPP1 prevents calcification and mortality, improves hypertension and cardiac function, and prevents intimal proliferation and osteomalacia in mouse models of ENPP1 deficiency. Therefore, newer treatments targeting genes are on the horizon. In this article, we review up to date knowledge of the understanding of GACI, its clinical, pathologic, and etiologic understanding and treatment in support of more comprehensive care of GACI patients.

A DRAMATIC RESPONSE TO DENOSUMAB: PROTRACTED HYPOCALCEMIA RELATED TO HUMAN T-CELL LYMPHOTROPIC VIRUS TYPE 1-ASSOCIATED ADULT T-CELL LEUKEMIA/LYMPHOMA

Objective

Adult T-cell leukemia/lymphoma (ATL) is known for its aggressive behavior, frequently presenting with hypercalcemia. ATL tumor cells uniquely secrete parathyroid hormone-related protein, viral peptides, and inflammatory cytokines, inducing a state of high bone turnover and activation of the receptor activator of nuclear factor kappa-B signaling pathway resulting in hypercalcemia.

Methods

A 54-year-old woman diagnosed with ATL presented with severe hypercalcemia refractory to bisphosphonate therapy. Treatment with denosumab was followed by protracted hypocalcemia and hypophosphatemia lasting approximately 5 months.

Results

Hypercalcemia due to acute ATL was responsive in this case to denosumab therapy.

Conclusion

Clinicians should be aware of the possibility of protracted hypocalcemia in patients with ATL exposed to denosumab therapy.

Hypercalcemic crisis due to adult T cell leukemia: a rare cause of paralytic ileus

Adult T cell leukemia- lymphoma is a rare aggressive malignancy of the peripheral T lymphocytes, caused by human T cell lymphotropic virus -1 (HTLV-1) infection. Hypercalcemia occurs in about 70% of patients with acute adult T cell leukemia. However, there are very few case reports of adult T cell leukemia presenting as a hypercalcemic crisis. We report a case of a 54-year-old male who presented with abdominal pain, constipation and altered sensorium. On examination he had generalized lymphadenopathy, hepatosplenomegaly and paralytic ileus. Investigation revealed hypercalcemic crisis with low parathormone (PTH) levels. Peripheral smear and bone marrow aspirate were consistent with adult T cell leukemia. HTLV-1 serology was positive. Despite the corrective measures for hypercalcemia and chemotherapy, he succumbed to the illness in a week.