Nonspecific interstitial pneumonia pattern is a frequent finding in patients with post-acute COVID-19 syndrome treated with bilateral orthotopic lung transplantation: current best evidence.

Patients with post-acute COVID-19 (PA-COVID) syndrome or long COVID-19 syndrome develop persistent symptoms and complications that last beyond 4 weeks of the initial infection. There is limited information regarding the pulmonary pathology in PA-COVID patients who require bilateral orthotopic lung transplantation (BOLT). Our experience with 40 lung explants from 20 PA-COVID patients who underwent BOLT is described. Clinicopathologic findings are correlated with best evidence from literature. The lung parenchyma showed bronchiectasis (n = 20) and severe interstitial fibrosis with areas resembling the nonspecific interstitial pneumonia (NSIP) pattern of fibrosis (n = 20), interstitial fibrosis not otherwise specified (n = 20), and fibrotic cysts (n = 9). None of the explants exhibited a usual interstitial pneumonia pattern of fibrosis. Other parenchymal changes included multinucleated giant cells (n = 17), hemosiderosis (n = 16), peribronchiolar metaplasia (n = 19), obliterative bronchiolitis (n = 6), and microscopic honeycombing (n = 5). Vascular abnormalities included thrombosis of a lobar artery (n = 1) and microscopic thrombi in small vessels (n = 7). Systematic literature review identified 7 articles reporting the presence in 12 patients of interstitial fibrosis showing the NSIP pattern (n = 3), organizing pneumonia/diffuse alveolar damage (n = 4) and not otherwise specified (n = 3) patterns. All but one of these studies also reported the presence of multinucleated giant cells and none of the studies reported the presence of severe vascular abnormalities. PA-COVID patients undergoing BOLT show a pattern of fibrosis that resembles a mixed cellular-fibrotic NSIP pattern and generally lack severe vascular complications. As the NSIP pattern of fibrosis is often associated with autoimmune diseases, additional studies are needed to understand the mechanism of disease and learn whether this information can be used for therapeutic purposes.

Distinguishing immunohistochemical features of alopecia areata from androgenic alopecia.

BACKGROUND: Distinction between alopecia areata (AA) and androgenic alopecia (AGA) can be made according to clinical presentation and biopsy findings. However, it is sometimes difficult to differentiate them, especially when the diffuse pattern of both AA and AGA is in the differential diagnosis of hair loss in androgen-dependent areas. OBJECTIVES: To evaluate the characteristics of inflammatory cell infiltration using CD3, CD4, CD8, and CD20 antigens, in AA and AGA to find some consistent histological clues for distinguishing these two entities. METHODS: A retrospective analysis of patients with diagnosed AA (30 cases) and AGA (30 cases) was performed based on the clinical and histopathological criteria. We studied immunohistochemical findings for CD3, CD4, CD8, and CD20 in all selected cases. RESULTS: Immunohistochemical stains for CD4 and CD20 were not helpful in differentiating AA from AGA, but the inflammation density for AA was significantly (P-value = .025, .001) higher than AGA in CD3 (specificity= 86.7% and sensitivity= 96.7%) and CD8 (specificity= 50% and sensitivity=86.6%). Our findings revealed that intrafollicular CD3 (P-value = .017) and CD8 (P-value = Ë‚.001) infiltrations were significantly higher in AA samples in comparison with AGA. CONCLUSION: Characterization of CD3 and CD8 in IHC samples is helpful, especially when the density of CD3 and CD8 T cells are significant in more than 50% of the infiltrated cells and are located intrafolliculary. Moreover, the most specific and sensitive test for differentiating of AA from AGA is CD3.

True volumetric method for flow cytometric enumeration of CD34 + stem cells and its agreement with a standard bead-based single-platform protocol.

BACKGROUND AIMS: Stem cells are commonly enumerated with bead-based methods in blood and marrow progenitor cell transplantation centers. We compared the International Society of Hematotherapy and Graft Engineering (ISHAGE) bead-based method with a true volumetric one that obviates the use of fluorescent beads for enumeration. METHODS: From 31 samples, including 15 peripheral blood samples and 16 leukapheresis products, CD34 (+) cells were enumerated with the single-platform bead-based ISHAGE method and a true volumetric method. After exclusion of two outliers, one from the peripheral blood group and the other from the leukapheresis group, the results were compared. RESULTS: In the peripheral blood category, no significant difference was observed. However, a proportional systematic error was seen in the leukapheresis group. The systematic error was corrected in the leukapheresis group using a regression line equation. The 95% confidence interval of differences was [-5.83, 2.18] for the peripheral blood and [-38.40, 38.77] for the leukapheresis group after correction of the systematic error. CONCLUSIONS: The true volumetric method is a simple and reliable approach that can be used instead of the more popular bead-based procedures.