Altered purine and pyrimidine metabolism in erythrocytes with purine nucleoside phosphorylase deficiency

Purine and pyrimidine metabolism was compared in erythrocytes from three patients from two families with purine nucleoside phosphorylase deficiency and T-cell immunodeficiency, one heterozygote subject for this enzyme deficiency, one patient with a complete deficiency of hypoxanthine-guanine phosphoribosyltransferase, and two normal subjects. The erythrocytes from the heterozygote subject were indistinguishable from the normal erythrocytes. The purine nucleoside phosphorylase deficient erythrocytes had a block in the conversion of inosine to hypoxanthine. The erythrocytes with 0.07% of normal purine nucleoside phosphorylase activity resembled erythrocytes with hypoxanthine-guanine phosphoribosyltransferase deficiency by having an elevated intracellular concentration of PP-ribose-P, increased synthesis of PP-ribose-P, and an elevated rate of carbon dioxide release from orotic acid during its conversion to UMP. Two hypotheses to account for the associated immunodeficiency—that the enzyme deficiency leads to a block of PP-ribose-P synthesis or inhibition of pyrimidine synthesis—could not be supported by observations in erythrocytes from both enzyme-deficient families.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44134/1/10528_2004_Article_BF00484238.pd

Low‐ and high‐risk human papillomavirus genotype infections in intra‐anal warts in HIV

Anogenital warts are often presumed to represent nondysplastic or low-grade anal intraepithelial neoplasia (LGAIN). We previously demonstrated that up to 20% of intra-anal warts in HIV-positive men who have sex with men (MSM) contain regions of high-grade AIN (HGAIN). To determine the causative human papillomavirus (HPV) types of low- and high- grade dysplastic areas in warts from HIV-positive MSM. A total of 42 intra-anal warts from 41 HIV-positive MSM were graded as nondysplastic, LGAIN or HGAIN. Whole-tissue sections (WTS) were analysed with the SPF10 polymerase chain reaction/LiPA25 HPV genotyping system. If the WTS contained multiple HPV types, dysplastic regions were isolated by laser capture microdissection (LCM) for HPV genotyping. Overall, 38 of 42 (91%) WTS tested positive for HPV DNA. Of these, 23 (61%) contained a single HPV type and 15 (39%) contained multiple HPV types. All LCM-selected regions contained no more than one HPV type. Ten of 42 (24%) WTS contained HGAIN disease, of which six (60%) were associated with a high-risk HPV (hrHPV) genotype. Twenty-three of 42 WTS contained LGAIN disease, of which two (9%) were associated with hrHPV. AIN lesions containing hrHPV types were identified using p16 staining. LGAIN lesions can be caused by high-risk HPV genotypes and vice versa. We therefore recommend routine follow-up and treatment of all dysplastic intra-anal warts for HIV-positive MS

Characteristics of mpox positive, versus mpox negative, and mpox unsuspected clients from the Centre of Sexual Health, Public Health Service of Amsterdam, 20 May to 15 September 2022

Background: In May 2022, an outbreak of mpox (monkeypox) in men-who-have-sex-with-men (MSM) emerged and quickly affected over 100 countries. In the early stages of the outbreak, overlap in symptoms with sexually transmitted infections (STI) made triage for mpox testing challenging. More information was needed on whom to screen and the main route of transmission. Objectives: We aimed to identify characteristics of mpox cases to further strengthen case definitions. We also compared Cycle threshold (Ct) values of the DNA positive mpox samples as a proxy for viral load by body location. Methods: From 20 May 2022 to 15 September 2022, we tested all MSM who presented with malaise, and/or ulcerative lesions, and/or proctitis and/or a papular-vesicular-pustular eruption attending the Centre of Sexual Health in Amsterdam, the Netherlands, for mpox, with a PCR test. In the same period, 6932 MSM mpox unsuspected clients were not tested. We compared those tested positive for mpox with those tested negative and those unsuspected for mpox. Results: Of the 374 MSM tested, 135 (36%) were positive for mpox. The mpox-positive MSM were older (median age, respectively, 36, 34 and 34 years, p = 0.019) and more often lived with HIV (30% vs. 16% and 7%, p < 0.001). Furthermore, mpox-positive patients more often reported receptive anal sex without a condom, sexualized drug use, more sex partners, and were more often diagnosed with bacterial STI (p < 0.001). Systemic symptoms and anogenital lesions were associated with mpox infection. For mpox-positive patients, anal samples (p = 0.009) and lesional samples (p = 0.006) showed significantly lower median mpox Ct values compared to throat samples. Conclusions: Mpox-positive patients more often reported receptive anal sex without a condom, had more sex partners and more often lived with HIV. Our results suggest that in the current mpox outbreak among MSM, sexual transmission is the main route