Introduction:
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked genetic disorder characterized by low levels of the G6PD enzyme.Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme which is found in the cytoplasm of cells. It helps in preventing cellular damage from reactive oxygen species (ROS).1 G6PD is the catalyst in the rate-limiting first step of the pentose phosphate pathway, which uses glucose-6-phosphate to convert nicotinamide adenine dinucleotide phosphate (NADP) into its reduced form, NADPH. In red blood cells, NADPH is critical in preventing damage to cellular structures caused by oxygen-free radicals.G6PD deficiency can induce methemoglobinemia by inhibiting NADPH-flavine reductase, which prevents the reduction of methemoglobin.Methemoglobin is unable to bind to oxygen, and the remaining oxyhemoglobin develops heightened oxygen affinity and diminished delivery, leading to tissue hypoxia.
Methods:
We report a case of severe hemolysis due to G6PD deficiency manifesting immediately after dialysis as methemoglobinemia in a 70 year old female never known to have any previous hemolytic episodes or previously diagnosed of G6PD deficiency
Results:
a 70 yr old female who presented with a history of fever for 2 days associated with cough, shortness of breath and drowsiness . She was a known case of type 2 Diabetes Mellitus, hypothyroidism, dementia and chronic kidney disease. She was undergoing maintainance hemodialysis for 2 years.
On examination, patient was drowsy but arousable , obeying commands , GCS-10/15 , PR – 90/min , BP -140/80mm hg ,SpO2 90% at room air, B/l Pitting oedema and pallor was present. Chest examination revealed bilateral basal crepts. Her initial investigation showed Hb – 10.2 , TLC -28.2,PLT- 188 , Urea – 142 , Sr Creatinine – 8.9 , Na – 124, K – 3.8. On day 3, patient underwent her scheduled hemodialysis, soon thereafter, she developed cyanosis of the extremities, which was confirmed by pulse oximetry (SO2 = 79%).In the ABG, spO2 was 98.6% and methHb was 13.1%.Her serials investigation showed a drop in hemoglobin level from 10.2 to 5.9mg/dl. A diagnosis of methemoglobinemia was made on the basis of the gap between the oxygen saturation on the monitor and on the ABGs and raised met-Hb% as measured by the blood gas analysis machine. She was further evaluated for hemolysis.Quantitative G6PD assay demonstrated a low G6PD level of 3.0U/gm.The onset of hypoxia and hemolytic crisis immediately after hemodialysis led to the suspicion of dialysis-associated methemoglobinemia.We tested our filtered water used for dialysis for nitrates and chlorine which came within acceptable limits. There were two more patients who underwent hemodialysis the same day but did not develop methemoglobinemia. Our patient was managed with 100% oxygen, ascorbic acid and blood transfusion was given. Patient gradually improved over a period of next 2-3 days.The methemoglobinemia gradually resolved, and her oxygen requirements decreased.
Conclusions:
Methemoglobinemia may present in patients with G6PD deficiency and severe hemolysis and treating it with methylene blue may be detrimental. Search and treatment for the root cause is mandatory.
It is usually diagnosed in childhood, but here we describe a first presentation of G6PD deficiency in an elderly patient. The case presented herein has many unusual features. First, it is a late presentation of G6PD deficiency.Second, the factor triggering such hemolysis is suspected to be inadequate clearance of chloramine from dialysis water considering the timing of hemolytic crisis immediately post dialysis.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.