Clinical and morphological practices in the diagnosis of transplant-associated microangiopathy: a study on behalf of Transplant Complications Working Party of the EBMT

Peripheral blood schistocytes in the acute phase after allogeneic or autologous stem cell transplantation assessed by digital microscopy

“…Enumeration of schistocytes is commonly performed by visually counting them during microscopic evaluation of blood smears. This procedure has a great interobserver variability and despite the recent publication of precise morphological criteria for the assessment of schistocytes, there is a poor standardization in the morphological interpretation and reporting between laboratories and observers . Those variabilities may depend on the area of the smear assessed, differences in the counting method, the number of RBC counted and the heterogeneity in reporting of results .…”

“…The absence of morphological standardization affects the accuracy of clinical diagnosis. This might lead to missing diagnosis of TA‐TMA or to the establishment of diagnosis based on physician's decision, rather than on diagnostic criteria . Automated hematology analyzers are more objective and with the proper manual confirmation of their results, software misjudgments can be avoided and a faster, more unbiased and always based on consensus criteria quantification of schistocytes can be conducted.…”

“…Additionally, we found significantly higher schistocyte counts at 2-3 months in patients with aGVHD and with HLA mismatch compared to patients without aGVHD or HLA mismatch ( observers. 10,14,18,19 Those variabilities may depend on the area of the smear assessed, differences in the counting method, the number of RBC counted and the heterogeneity in reporting of results. 13 This absence of standardization can lead to unreliable diagnostic information, and it can thus affect the treatment and the clinical outcome.…”

A key step towards setting a benchmark for tackling transplant‐associated thrombotic microangiopathy

“…(Gooley et al , ; D’Souza et al , ) Despite these advances, several complex post‐HCT toxicity syndromes that share areas of overlapping pathobiology involving endothelial injury and often underlying allogeneic‐mediated reactivity continue to contribute considerable morbidity and risk of mortality. (Cooke et al , ; Carreras & Diaz‐Ricart, ; Panoskaltsis‐Mortari et al , ; Dalle & Giralt, ; Cornell et al , ; Rodrigues‐Diez et al , ; Moiseev et al , ; Pagliuca et al , ) In the modern era, perhaps the most illustrative of these syndromes is transplant‐associated thrombotic microangiopathy (TA‐TMA), a potentially devastating complication resulting from multifactorial endothelial damage and subsequent complement activation leading to microangiopathic haemolysis, microvascular thrombosis, and eventually end‐organ damage. (Laskin et al , ; Jodele et al , ; Postalcioglu et al , ; Dvorak et al , ) Recent evidence suggests that the mechanistic link between endothelial damage and subsequent complement activation may be the formation of neutrophil extracellular traps that activate the classical and alternative complement pathways further propagating of microvascular injury.…”

Recent developments in transplant-associated thrombotic microangiopathy

“…If proteinuria and an increased level of sC5b-9 concentration are observed, there is a great risk of poor outcome, indicating the need for aggressive treatment. [9]. A questionnaire of the diagnostic methods of TA-TMA was sent to clinicians and morphologists.…”