Breaking COVID-19 News! Sri Lankan Physicians Warn That Mild SARS-CoV-2 Infections Can Trigger Macroamylasemia!

COVID-19 News: In the ever-evolving landscape of COVID-19 research, new and intriguing connections continue to emerge. Recently, Sri Lankan physicians from the National Hospital of Sri Lanka made a new discovery that may shed light on an unusual condition known as macroamylasemia and its potential association with mild SARS-CoV-2 infections. This revelation highlights the intricate interplay between viral infections, the immune system, and the delicate balance of enzymatic processes within the human body.


 
Macroamylasemia is a rare medical condition, affecting only 0.5% to 1.5% of the general population. It is characterized by elevated serum alpha-amylase levels, a digestive enzyme crucial for breaking down carbohydrates. However, what sets macroamylasemia apart is the absence of a corresponding increase in urine alpha-amylase levels, a hallmark of the condition.
 
It should be noted that there has been no previous case studies or COVID-19 News reports about SARS-CoV-2 infections and Macroamylasemia but some experts are speculating that perhaps some of the newer SARS-CoV-2 sub-lineages that are already exhibiting greater tropism for the gastrointestinal tract could also be responsible for this new manifestation and it is expected that we should see more such cases soon.
 
Understanding Macroamylasemia
To comprehend the significance of the link between macroamylasemia and COVID-19, it's essential to first grasp the fundamentals of both conditions. Alpha amylase, a vital enzyme involved in carbohydrate digestion, is produced primarily by the pancreas and salivary glands in healthy adults. However, smaller amounts can also be found in various organs like the Fallopian tubes, testes, lungs, thyroid gland, tonsils, mammary glands, and sweat glands. Importantly, alpha amylase can exist in two distinct forms: the pancreatic or p-isoenzyme and the non-pancreatic, salivary, or s-isoenzyme.
 
Most commonly macroamylasemia results from the formation of immune complexes between amylase and immunoglobulins.
 
Macroamylasemia was first described in 1964 and is characterized by the formation of macromolecular complexes (weighing more than 400 KDa) between serum amylase and other serum proteins, notably immunoglobulins A and G. These large complexes are too substantial for the nephrons in the kidneys to filter into the urine, resulting in their accumulation in the bloodstream. As a rare and benign condition, macroamylasemia often goes unnoticed until it is detected during routine blood tests or through investigations for unexplained symptoms.
 
The COVID-19 Connection
As we continue to unravel the complexities of the SARS-CoV-2 virus and its interactions within the human body, researchers have discovered a compelling link between COVID-19 and macroamylasemia. During seroconversion, when the body begins producing specific antibodies against the virus, patients with COVID-19 experience a surge in SARS-CoV-2-specific immunoglobulins and various plasma proteins.
 
Intriguingly, these proteins can bind with alpha amylase molecules, creating macromolecules. This binding phenomenon extends the half-life of amylase due to reduced renal clearance, poten tially resulting in the development of macroamylasemia. To put it simply, the immune response to COVID-19, characterized by the production of immunoglobulins, may inadvertently trigger the formation of these macromolecular complexes, leading to elevated serum amylase levels.
 
The Unprecedented Case
In the annals of medical literature, the Sri Lankan physicians' report marks the first documented case of macroamylasemia in a patient with COVID-19. The patient in question was a 70-year-old individual with a history of hypertension and asthma, who was receiving treatment for mild COVID-19. However, he presented an unexpected symptom - a burning epigastric pain that persisted for a day.
 
Despite the absence of classic pancreatic pain, his serum amylase levels were alarmingly high, reaching 663 U/L. Notably, his renal functions and basic investigations appeared normal, raising initial suspicions of mild acute pancreatitis. Accordingly, he received symptomatic management while awaiting further radiological investigations, ultimately recovering from COVID-19 and being discharged from the hospital.
 
However, his journey did not end there. During follow-up appointments at the gastroenterology clinic, the patient continued to exhibit elevated amylase levels without any signs of pancreatic pain. With clinical and radiological assessments failing to reveal any evidence of acute pancreatitis or other abdominal pathologies, the medical team embarked on a comprehensive evaluation for hyperamylasemia.
 
Advanced imaging techniques, including contrast-enhanced computed tomography (CECT) scans of the abdomen, thorax, and pelvis, yielded results showing a normal pancreas and the absence of solid organ malignancies. Upper and lower gastrointestinal endoscopies were equally unremarkable, with findings limited to mild antral gastritis. Notably, the amylase creatinine clearance ratio was a mere 0.2%, further supporting suspicions of macroamylasemia. Pre-PEG (polyethylene glycol) amylase concentration was measured at 644 U/L, while post-PEG amylase concentration stood at a mere 10 U/L, accompanied by an extremely low post-PEG recovery rate of 1.55%. Collectively, these findings pointed unmistakably to the diagnosis of macroamylasemia.
 
Implications and Considerations
The implications of this novel discovery extend beyond the confines of a single medical case. It underscores the importance of considering alternative diagnoses when dealing with patients who exhibit elevated serum amylase levels, particularly in the context of COVID-19. While the pandemic primarily manifests with respiratory symptoms, the presence of abdominal pain or other gastrointestinal symptoms should not be overlooked, as they may signify underlying conditions unrelated to the viral infection.
 
Moreover, the diagnostic journey for patients with high amylase levels can be arduous and exhaustive. Studies have shown that after extensive investigations, a significant percentage of such patients remain without a specific diagnosis. Therefore, the identification of macroamylasemia in a patient with hyperamylasemia holds significant value for both the healthcare system and the patient. It can prevent unnecessary hospital admissions, reduce the financial burden of extensive investigations, and streamline the treatment process.

Conclusion
The emergence of macroamylasemia in a patient with mild COVID-19 has provided a unique perspective on the intricacies of the human immune response to viral infections. It highlights the potential for the immune system's dysregulation to lead to rare but clinically significant conditions. The case serves as a reminder for healthcare professionals to maintain vigilance in the face of atypical symptoms and laboratory findings, especially in the context of a global pandemic.
 
As we continue to grapple with the ever-evolving challenges posed by COVID-19, this discovery underscores the importance of collaboration between researchers, clinicians, and the scientific community. By sharing and disseminating knowledge about rare and unexpected connections, we move one step closer to understanding the full spectrum of this enigmatic virus's impact on the human body. In the quest for effective management and treatment of COVID-19, every piece of the puzzle counts, and the case of macroamylasemia offers a valuable addition to our growing body of knowledge.
 
The study findings were published on a preprint server but is currently being peer reviewed for publication into the journal: BMV Infectious Diseases.
https://www.researchsquare.com/article/rs-3241111/v1
 
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