An anti-i biphasic hemolysin in chronic paroxysmal cold hemoglobinuria

ABO blood group antigens and differential glycan expression: Perspective on the evolution of common human enzyme deficiencies

Enzymes catalyze biochemical reactions and play critical roles in human health and disease. Enzyme variants and deficiencies can lead to variable expression of glycans, which can affect physiology, influence predilection for disease, and/or directly contribute to disease pathogenesis. Although certain well-characterized enzyme deficiencies result in overt disease, some of the most common enzyme deficiencies in humans form the basis of blood groups. These carbohydrate blood groups impact fundamental areas of clinical medicine, including the risk of infection and severity of infectious disease, bleeding risk, transfusion medicine, and tissue/organ transplantation. In this review, we examine the enzymes responsible for carbohydrate-based blood group antigen biosynthesis and their expression within the human population. We also consider the evolutionary selective pressures, e.g. malaria, that may account for the variation in carbohydrate structures and the implications of this biology for human disease.

Adult paroxysmal cold hemoglobinuria following mRNA COVID-19 vaccination

Paroxysmal cold hemoglobinuria (PCH) is an extremely rare subtype of autoimmune hemolytic anemia (AIHA) in adults. PCH is caused by the biphasic Donath-Landsteiner (DL) antibody which fixes complement to red blood cells at low temperatures and dissociates at warmer temperatures, leading to complement-mediated intravascular hemolysis. Autoimmune hematological disorders including AIHA and immune thrombocytopenia have been reported to develop following the mRNA COVID-19 vaccination. However, PCH developing subsequent to mRNA vaccination has never been reported. We report a 59-year-old male who developed PCH approximately a month after his second mRNA COVID-19 vaccination.

A rare case report of autoimmune haemolytic anemia in a female child due to a Donath-Landsteiner antibody

Paroxysmal cold hemoglobinuria is a rare form of autoimmune hemolytic anemia caused by the Donath-Landsteiner autoantibody. The condition is characterized by the presence of an IgG biphasic hemolysin with specificity to the P blood group antigen. The antibody biphasic action may be demonstrated in the Donath-Landsteiner test. While paroxysmal cold hemoglobinuria can be manifested at any age, it typically appears in children following a viral upper respiratory syndrome or immunization, though rarely. This report describes a 23-months old girl presented with 5 days history of fever, erythrocytopenia, leukocytosis and occurrence of dark urine. On admission, the physical examination showed pallor, no scleral icterus, a mild hyperemic throat and no hepatosplenomegaly. The investigations revealed severe anemia with hemoglobin of 44g/L, increased reticulocyte count (10.67%), elevated lactate dehydrogenase (2603IU/L), decreased serum haptoglobin (0.159g/L), normal G6PD. Direct antiglobulin test was positive with C3d and C3c complement components only. Direct and indirect Donath-Landsteiner tests were positive. The girl was treated with a intravenous immunoglobulin infusion and Cefotaxime. She received transfusion of red blood cells, crossmatched, although P antigen untyped. Despite this in vitro serological incompatibility she had a hemoglobin increase. The patient was discharged in stable condition on the seventh day following admission. Paroxysmal cold hemoglobinuria is a hemolytic anemia for which a specific diagnostic test is available. Timely recognition of the disease by pediatricians is crucial as well as the highly skilled hospital blood bank staff performing Donath-Landsteiner testing.

Paroxysmal Cold Hemoglobinuria in an Adult with Respiratory Syncytial Virus

Paroxysmal cold hemoglobinuria (PCH) is a rare form of cold autoimmune hemolytic anemia first discovered in the early 20th century in adults with tertiary syphilis. Today, it is more commonly seen in children as a life-threatening anemia during a viral upper respiratory tract infection (URI). Although respiratory syncytial virus (RSV) has previously been reported to cause PCH in a child, herein we present the first documented case in an adult. The Donath–Landsteiner (DL) test, the diagnostic test for PCH, was positive on two separate occasions. The patient was treated successfully with warming and avoidance of cold temperatures. To facilitate identification of this rare entity by clinicians, we include a discussion about the pathophysiology, diagnosis, and treatment of PCH.

Paroxysmal cold hemoglobinuria due to an IgA Donath-Landsteiner antibody

Paroxysmal cold hemoglobinuria (PCH) is an autoimmune hemolytic anemia (AIHA) characterized by the presence of a Donath-Landsteiner (D-L) antibody. PCH occurs most commonly in young children and is associated with acute, often self-limited hemolytic anemia. The D-L antibody is classically a biphasic IgG anti-P autoantibody identified by the D-L test. Rare case reports confirm the existence of IgM D-L antibodies. We report the case of a 2-year-old male diagnosed with acute AIHA and found to have PCH caused by an IgA D-L antibody. The clinical course and treatment of this condition, which has not been reported previously, are described.

A case study of a child with chronic hemolytic anemia due to a Donath-Landsteiner positive, IgM anti-I autoantibody

In children, paroxysmal cold hemoglobinuria (PCH) is generally considered an acute self-limited autoimmune hemolytic anemia caused by an IgG biphasic auto-anti-P antibody identified by the Donath-Landsteiner (D-L) test. We report a case of a 5-year-old female with a chronic hemolytic anemia. The etiology of the hemolysis appears to be an unusual D-L positive, IgM antibody with specificity for the I antigen. The clinical course is described and a discussion of PCH and the D-L antibody is presented. We also discuss intravenous immunoglobulin infusions as a therapy for children with this form of severe chronic autoimmune hemolytic anemia.

Erythropoiesis: Paroxysmal Cold Haemoglobinuria: A Clinico-Pathological Study of Patients with a Positive Donath-Landsteiner Test

52 patients (30 male, 22 female) with paroxysmal cold haemoglobinuria (PCH) were identified by critically examining the records of all cases with Donath-Landsteiner antibodies seen over a 37 year period. Although ages ranged from 1-82 years, PCH was much commoner in young children; the median age at presentation was 5 and the peak incidence, 0.4 per year per 100,000 of the population at risk, was in the 4 years and under group. 44 patients had acute transient PCH, 3 chronic non-syphilitic PCH and 1 chronic syphilitic PCH; 4, in whom the positive Donath-Landsteiner tests were incidental findings, could not be classified. Acute PCH typically presented in young children as sudden onset of malaise, haemoglobinuria and pallor, often associated with mild jaundice - all 30 patients who were 13 or younger had this type. There was usually a history of a recent viral type infection, most commonly of the upper respiratory tract. The occurrence of acute PCH had no obvious relation to exposure to cold. Dramatic and rapid falls in haemoglobin level were common, often accompanied initially by relative or absolute reticulocytopenia. The illness was severe, but the prognosis was generally good and the majority of patients had completely recovered within one month, some requiring no treatment. In approximately 68% of patients, blood transfusion was needed; the P blood group was not taken into account, but the patients were kept warm throughout. Steroids (usually prednisolone) were given in many cases; but since there was no evidence to support their benefit, it was recommended that they were stopped as soon as the diagnosis was confirmed. Chronic non-syphilitic PCH was much rarer; the patients had a characteristic presentation of severe systemic symptoms (paroxysms) and haemoglobinuria brought on by exposure to cold. The clinical manifestations varied in intensity between individuals; at the extreme, severe debility was experienced over many years. Warmth and avoidance of cold were an effective treatment, though in a severely afflicted patient, an attack could be precipitated by relatively little exposure to cold. With chronic syphilitic PCH there was the added need to treat the specific infection. The direct antiglobulin test was almost always positive (50 out of 51 cases tested), with C3d coating the red cells. The Donath-Landsteiner antibodies were of IgG class, but this was rarely demonstrated unless direct antiglobulin tests were carried out at 4 degrees C. The antibodies showed the classical anti-P specificity in 27 of the 30 patients tested; other specificities were unusual. Although acting much better as haemolysins, Donath-Landsteiner antibodies could also cause weak agglutination at room temperature. This was paralleled in vivo by predominantly intravascular haemolysis with an extravascular component. Diagnosis was usually easy when PCH was suspected, though in some patients Donath-Landsteiner tests did not become positive until more sensitive techniques involving papainised red cells or two-stage procedures were employed. Of particular interest was the association in some cases with lymphoproliferative disorders, collagen disease, myelodysplastic syndrome, delayed haemolytic transfusion reaction and other types of autoimmune haemolytic anaemia. In one patient, an aetiological relationship was confirmed by a saline extract of lymphoma tissue behaving as a strong Donath-Landsteiner antibody with the same anti-P specificity as the serum. 4 patients had other types of autoimmune haemolysis concomitant with, but distinct from, the PCH; in 3 cases this was cold haemagglutinin disease and in one it was warm type autoimmune haemolytic anaemia.