Anti-Ma-1 and Anti-Ma-2 Antibodies in Isolated Fatal Hypothalamitis

Primary autoimmune hypothalamitis: management strategies and long-term outcomes in a tertiary care setting with a focused review of literature

BACKGROUND

Primary autoimmune hypothalamitis is an exceptionally rare inflammatory condition of the hypothalamus. Its etiology, clinical presentation, and management are not well established, with significant overlap and distinctions from hypophysitis.

MATERIAL AND METHODS

This study presents management and outcomes of patients with autoimmune hypothalamitis managed at a tertiary care centre. A literature review was also performed analyzing clinico-demographic, biochemical, radiological, and therapeutic characteristics.

RESULTS

There were 4 cases of autoimmune hypothalamitis out of 2200 sellar-suprasellar lesions managed over the past decade at our centre. Case 1 presented with arginine vasopressin (AVP) deficiency and adipsia, showing partial radiological response to glucocorticoids. Case 2 presented with neuropsychiatric features, with limited improvement on therapy. Case 3 had panhypopituitarism with stable disease on imaging, while Case 4 had AVP deficiency and hypogonadism with no significant radiological or hormonal recovery post therapy. Literature review (n = 34) of all cases showed female predominance (88%), but minimal association with pregnancy (6%). Polyuria-polydipsia was the most common presentation (81%), followed by memory disturbances and/or confusion (35%). Secondary hypogonadism was most common (88%) hormone deficiency followed by hypocortisolism (85%) and AVP deficiency (82%). T2 hyperintensity was the most common feature (95%) on MRI. Glucocorticoids enabled partial radiological response in most cases (82%), with hormonal recovery being less common (18%). Adjunctive medical therapy was required in 54.1% cases (most commonly azathioprine). Surgery was primarily used for biopsy and adjunctive radiotherapy in 3 cases. FDG-PET demonstrated utility in diagnosis, systemic involvement and follow-up.

CONCLUSION

Autoimmune hypothalamitis remains a challenging diagnosis due to its rarity and overlapping features with other sellar pathologies. Histopathological evaluation or circulating antibodies can point towards the diagnosis. FDG-PET can be valuable in diagnosis and follow-up. Glucocorticoids are the mainstay of treatment, with partial radiological response commonly observed.

Hypothalamitis: A Novel Autoimmune Endocrine Disease. A Literature Review and Case Report

CONTEXT

The relationship between the endocrine system and autoimmunity has been recognized for a long time and one of the best examples of autoimmune endocrine disease is autoimmune hypophysitis. A better understanding of autoimmune mechanisms and radiological, biochemical, and immunological developments has given rise to the definition of new autoimmune disorders including autoimmunity-related hypothalamic-pituitary disorders. However, whether hypothalamitis may occur as a distinct entity is still a matter of debate.

EVIDENCE ACQUISITION

Here we describe a 35-year-old woman with growing suprasellar mass, partial empty sella, central diabetes insipidus, hypopituitarism, and hyperprolactinemia.

EVIDENCE SYNTHESIS

Histopathologic examination of surgically removed suprasellar mass revealed lymphocytic infiltrate suggestive of an autoimmune disease with hypothalamic involvement. The presence of antihypothalamus antibodies to arginine vasopressin (AVP)-secreting cells (AVPcAb) at high titers and the absence of antipituitary antibodies suggested the diagnosis of isolated hypothalamitis. Some similar conditions have sometimes been reported in the literature but the simultaneous double finding of lymphocytic infiltrate and the presence of AVPcAb so far has never been reported.

CONCLUSIONS

We think that the hypothalamitis can be considered a new isolated autoimmune disease affecting the hypothalamus while the lymphocytic infundibuloneurohypophysitis can be a consequence of hypothalamitis with subsequent autoimmune involvement of the pituitary. To our knowledge this is the first observation of autoimmune hypothalamic involvement with central diabetes insipidus, partial empty sella, antihypothalamic antibodies and hypopituitarism.

Hypothalamitis and pituitary atrophy

Hypothalamitis is a rare inflammatory disorder involving the hypothalamus and classified as primary, or isolated, and secondary hypothalamitis. Secondary hypothalamitis although very rare is more common than the primary one and may occur in patients affected by autoimmune diseases such as autoimmune hypophysitis, systemic autoimmune diseases, infective diseases in patients affected by immune-deficit, paraneoplastic encephalitis, or in patients treated with immune checkpoint inhibitors. In accordance with the rarity of this disease, diagnosis and management of hypothalamitis prove to be challenging. The diagnosis requires a high index of clinical suspicion. The main symptoms may be: various degrees of hypopituitarism, neuropsychiatric and behavioral disorders, and disturbances of autonomic and metabolic regulation. Magnetic resonance images play a crucial role in the diagnosis of hypothalamitis and in the exclusion of a neoplastic lesion. Therapeutic management should be oriented according to the disease etiology. In most cases, after ruling out infective hypothalamitis, the mainstay of therapy consists of immunosuppressive treatment. Great attention should be paid to hormonal replacement therapy, if partial or total hypopituitarism is present, in particular in patients affected by diabetes insipidus, central hypoadrenalism and hypothyroidism. According to the complexity of this disease, a multidisciplinary approach is strongly advocated to reach an early diagnosis and an integrated therapy.

Anti-Ma encephalitis masquerading as Wernicke encephalopathy

BACKGROUND

Anti-Ma encephalitis is a disease usually associated with testicular cancer in young male patients. Anti-Ma encephalitis presented as Wernicke encephalopathy-like symptoms and with gastric cancer is rare. Here, we report a case of anti-Ma encephalitis with gastric cancer in an elderly patient, which has been misdiagnosed of Wernicke encephalopathy.

CASE REPORT

A 71-year old male with a history of alcohol abuse was admitted to the hospital because of progressive dizziness, diplopia and anorexia lasted for 1 month. He was initially diagnosed as Wernicke encephalopathy. However, this patient failed in the treatment of VitB1. The blood and cerebrospinal fluid examination found the presence of anti-Ma1/2 antibodies. ¹⁸F-FDG PET-MR showed symmetrical hypermetabolic changes on the bilateral hypothalamus, basal ganglion and brainstem, as well as gastric neoplasms with liver metastasis. The patient was finally diagnosed with anti-Ma encephalitis.

CONCLUSION

Anti-Ma encephalitis should be suspected in patient with Wernicke encephalopathy-like symptoms but failed VitB1 treatment.